T VN

1

T VN

1.Tnh cp thit ca ti lun n

Tng huyt p ngy nay vn ang l vn thi s. Theo c tnh ca cc nh khoa hc M t l tng huyt p trn th gii nm 2000 l 26,4% (tng ng 972 triu ngi, ring cc nc ang pht trin chim 639 triu) v s tng ln 29,2% vo nm 2025 vi tng s ngi mc bnh tng huyt p trn ton th gii khong 1,56 t ngi m 3/4 trong s l ngi thuc nc ang pht trin [62]. Cc s liu iu tra thng k tng huyt p Vit Nam cho thy t l tng huyt p nm 1960 chim 1,6% dn s, 1982 l 1,9%, nm 1992 tng ln 11,79% dn s, 2002 Min Bc l 16,3%, ring thnh ph H Ni c t l 23,2%, cn nm 2004 Thnh ph H Ch Minh l 20,5% [1] v nm 2007 ti Tha thin -Hu l 22,77% [11]. Bn cnh , tng huyt p cn l yu t nguy c bnh ng mch vnh. Khi qun th dn s bin i gi hn, cng theo s ngi tng huyt p c bnh ng mch vnh cng ph bin. Hn na, hai bnh ny c quan h c bit ring trong bnh sinh v iu tr. Tuy nhin, nghin cu tc ng ca huyt p ln tn thng ng mch vnh (MV) v iu tr bnh ng mch vnh trn bnh nhn tng huyt p l nh th no? y l vn cn thit do yu cu thc tin t ra. Mc d vy, Vit Nam vn cha c nhiu ti nghin cu vn ny.

S khc nhau gia huyt p trung tm v ngoi bin, cng nh thay i vai tr d bo hu qu bnh tim mch ca cc thng s huyt p theo tui l do c im n hi ca ng mch hay ni khc hn l cng ng mch m c bit l ng mch ch quyt nh. Vy thc s, cng mch c vai tr g trong quan h gia huyt p ln mch vnh, cng nh trong tin trnh x va ng mch vnh ngi tng huyt p? Mt khc, mi bin c tim mch u xy ra qua ng ng mch hay cch khc hn ng mch l mc tiu, l mu s chung ca nhiu bin c tim mch. Cc yu t nguy c tim mch iu phi tc ng ca chng nh thay i cu trc, tnh cht v chc nng thnh mch, thnh phn ni mc thn ng mch v thng khc nhau gia cc ging mch khc nhau. Pht hin v gim st tn thng di lm sng, th hin nh hng ly tch v phi hp ca cc yu t nguy c trong lm suy yu tnh ton vn thnh ng mch, c tim nng ci thin su sc phn tng nguy c tim mch v cho php can thip sm, ngn hoc lm suy yu qu trnh tin trin bnh. Tm quan trng vic nh gi tnh ton vn thnh ng mch c khng nh bi cc nghin cu chng minh gim chc nng mch p hay cng ng mch ln l yu t nguy c c lp cho bin c tim mch tng lai. Chc nng mch p ng mch suy yu hay cng mch c xem l yu t d bo nguy c c lp cc bin c mch mu do lo ha v cc bnh cnh khc bao gm bnh ng mch vnh, suy tim xung huyt, tng huyt p v bnh i tho ng. Bin i hot ng c hc thnh mch mu tc ng n pht trin v ti cu trc tt c cc phn thnh ng mch, nh hng tim tng s pht trin v tin trin bnh ng mch. Tm li, nhng vn trn cn thit trong thc hnh lm sng nhng hin ti cha c nhiu nghin cu cp, gii quyt rt ro nhng vn cp thit y nn chng ti tin hnh nghin cu ny.2. Mc tiu ca lun n:

2.1. Kho st c im hnh nh v mc tn thng ng mch vnh qua chp mch bnh nhn tng huyt p nguyn pht c bnh ng mch vnh. 2.2. nh gi cng ng mch bng vn tc sng mch ng mch ch v xc nh mi lin quan ca n vi mc tn thng ng mch vnh trn bnh nhn tng huyt p nguyn pht c bnh ng mch vnh.

3. ngha khoa hc

Nghin cu nu r c im v mc tn thng ng mch vnh bnh nhn tng huyt p nguyn pht v lm sng t mi quan h sinh l bnh gia hai bnh ny vi nhau.

Lm r vai tr ca cng ng mch trn ngi tng huyt p c bnh MV cng nh nh hng ca n trn tin trnh x va ng mch vnh.

4. ngha thc tin

m bo k hoch iu tr tng huyt p (THA) bao qut v hiu qu hn, mc tiu iu tr THA tr nn r rng hn trn bnh nhn THA v THA c bnh MV.

Nhn thc tt hn bnh MV ngi THA nguyn pht m khi in tm b mt gp kh khn, hn ch nht nh trong pht hin v chn on bnh ny. T , khuyn co thi thch ng ca cc nh lm sng khi i din vi nhm bnh ny.

C th theo di tin trin v tn thng c quan ch, hiu qu cng nh mc p ng iu tr bnh MV bnh nhn THA. ng dng nh gi vn tc sng mch ng mch ch cho phn tng nguy c, pht hin nhng i tng nguy c cao bnh tim mch ni chung v bnh MV ni ring c k hoch thay i li sng hay iu tr gip ngn s tin trin bnh MV v bnh tim mch trong tng lai.

Chng 1TNG QUAN TI LIU

1.1. C CH TNG HUYT P V BNH NG MCH VNH

1.1.1 Cc c ch vt l v huyt ng hcTrong bnh THA va tng nhu cu tiu th oxy c tim va gim lu lng vnh hoc t nht gim d tr vnh. Nhu cu tiu th oxy tng do tng hu gnh lm sc cng thnh tim tng, cng nh ph i tht tri nu c. Gim d tr vnh c th do tc nghn mch vnh bi mng x va, ti cu trc mch vnh va v nh, HATTr thp gim p lc ti mu mch vnh.

Cc lc vt l (p sut v lu lng) l nhng yu t quyt nh chnh cho hot ng chc nng v cu trc tim, cng nh nh hng n qu trnh ti cu trc v x va M. HATT tng, tng tr khng ng ra tht tri va tng sc cng thnh tim, lm tng nhu cu oxy c tim. M rng khong ALM (pulse pressure) v THA tm thu bnh nhn ln tui gn nh lun do tr khng MC cao khng thch hp. Tr khng cao do ng knh MC gim hoc do dy thnh, bin i tng cng thnh MC. Qu trnh lo ha lm gim v ph v tnh n hi mch mu, tng lng ng collagen. Qu trnh thoi ha hin r hn bnh nhn THA tm thu n c.

HATT khng ging nhau cc M do thay i c tnh cu trc, chc nng lin quan lan truyn v di li ca sng mch. HATT trung tm b nh hng c bit bi sng phn hi. Lc sng ny tng dn theo tui v nhng thay i cu trc thnh M. Tng di li ca snglm tng HATT trung tm, tng gnh tht v cng c tim, dn dn gy ph i tht tri v TN [94], [107].

Nhng ngi sm b THA hoc HA bnh thng cao, sc cng thnh mch tng ph v v b gy cc si n hi, cng nh tng lng ng collagen trong M. Hu qu gim co gin mch mu. Nhng bt thng cu trc, ri lon chc nng ni mc do lo ha v THA gp phn tng CM ngi cao tui lm tng ALM v THA tm thu n c sau ny. CM (tng vn tc v sng phn x) lm tng hu gnh v HATT trung tm, ng thi gim HATTr gim p lc ti mu vnh. Tng HATT MC trung tm do lo ho, bnh THA v/ hoc bnh M, lm tng ng k cng c tim, bnh tim lin quan p lc bao gm c bnh MV v ph i tht tri [94], [107].

1.1.2 Stress oxy haStress oxy ha l c tnh quan trng trong bnh THA v bnh sinh x va. Pht sinh qu mc cc gc oxy phn ng (reactive oxygen) lm tn hi cc t bo ni m hay t bo c, dn n thay i cp thi cng nh lu di cu trc, chc nng. V d, lp ni m tn thng lm mt kh nng gin mch, gp phn gy huyt khi v tc mch. Cc gc oxy phn ng kch thch phng thch cytokine v cc phn t bm dnh b mt ni m b tn thng, lm bch cu lu thng tng bm dnh thnh mch mu. Qu trnh vim mch nh trng din l nn tng cho x va pht trin v gp phn tng huy ng bch cu tun hon vo lp di ni m. Cht trung gian gy vim kch hot t bo c trn, lm cc t bo ny tng sinh v di chuyn t trung mc ti ni mc. S hin din ri lon lipid mu, cc n bo trong thnh mch nut LDL-C oxy ha v tr thnh i thc bo cha y lipid, l li ca mng x va. Khi c thng tn, i thc bo ti ch tit cc cht metalloproteinase v cathepsins, cc cht ny lm mt n nh mng x va gy t v mng bm v phng thch cc yu t m gy ra huyt khi, tc ng mch vnh v nhi mu c tim cp [94], [107].Cc qu trnh ny gy bt thng cu trc vi tun hon gp trong THA mn. m mch mu, cc tc nhn chnh gy tn thng oxy ha l nhng cht oxy ha NAD(P)H, cht ny c kch hot bi cc lc c hc (v d THA), cc hormon (c bit l angiotensin II), cholesterol oxy ha v cc cytokine. Khi cc t bo c kch hot, nhng cht oxy ha ny d lm pht sinh anion peoxide (O2-). O2- d dng phn ng vi oxide nitric to thnh peroxynitrite (ONOO-) l cht chuyn ha gy c v rt ngn thi gian na vng i ni m, ni sn sinh oxide nitric. Cc gc oxy phn ng (reactive oxygen) nh hydrogen peroxide v ONOO- nhanh chng oxy ha lipid, gy x va nhiu hn v gy thay i kiu hnh nh tng sinh t bo c trn mch mu, bc l phn t bm dnh v gy lo ha t bo mch mu. Nhiu cht ng dng oxy ha NAD(P)H gy bc l lp t bo c trn mch mu v ni m, lm tng qu trnh x va v tn thng M [94], [107].1.1.3 Cc yu t chuyn ha v th dch Cc c ch THA cng l cc c ch gy tn thng c quan ch, bao gm mch vnh v c tim. Nhng c ch ny gm tng hot h thn kinh giao cm v h renin-angiotensin-aldosterone (H RAA); gim phng thch hoc gim hot cc cht gin mch, v d oxide nitric, prostacyclin v cc peptide li niu; cc bt thng cu trc v chc nng M, c bit ri lon chc nng ni m; tng cc yu t tng trng v cytokin gy vim trong h thng M. Da vo cc c ch , cc loi thuc h p mang li hiu qu c li trn mch mu thng qua tc dng h p c lp [107].

Angiotensin II gy THA v tn thng c quan ch, trong c x va ng mch bi rt nhiu c ch. Angiotensin II tc dng trc tip ln s co tht v khng thnh mch, tng hp v phng thch aldosterone, tng hot h thn kinh giao cm v tngcatecholamine t tuyn thng thn v

u tn cng h thn kinh giao cm ngoi bin. Aldosterone tc ng ging hoc lm tng c tnh ln mch mu ca angiotensin II v norepinephrin. Angiotensin II trc tip xc tin qu trnh ph i t bo c trn mch mu v tim thng qua hot ng ca th th 1 ca angiotensin II (AT1) v gin tip qua kch thch mt s yu t tng trng v cytokine, v d nh yu t tng trng tiu cu, yu t tng trng nguyn bo si, yu t tng trng insulin-like v yu t tng trng chuyn i v cc th th cng nh protein-1 gy ha hng ng t bo n nhn v phn t-1 bm dnh t bo mch mu. Cui cng, mi lin quan gia kch hot h RAA v ly gii fibrin. Angiotensin II gy hnh thnh cht c ch-1 hot ha plasminogen qua tc ng ph thuc th th AT1 ln t bo ni m, trong khi ACE (men chuyn) gim hot ha sn xut plasminogen m bng gim Bradykinin, y l mt cht kch thch mnh hot ha plasminogen ni m [77], [94], [107].Thuc c ch men chuyn v c ch th th Angiotensin cho thy hiu qu lm gii hn phn ng oxy ha mch mu bng ngn hot ha cht oxy ha NAD(P)H, do c ch h RAA ngoi tc dng h p, cn c tc dng bo v mch mu. Hn na, c bng chng lin quan gia h RAA v ri lon lipid mu. Tng cholesterol mu lm tng hot h RAA, nht l tng hot ng v mt th th AT1 mch mu v tng tng hp Angiotensin II h thng. H RAA cng gy lng ng LDL-C thnh M [94], [107].

1.2. CNG NG MCH 1.2.1. nh ngha ca cng ng mchCng ng mch (arterial stiffness) hay cng mch l thut ng dng ch kh nng co gin ng mch theo chu k co bp tim. Cc thut ng khc nh s co gin (Compliance), gin n (Distensibility) v n hi (Elasticity) l cc kha cnh khc nhau ca cng ng mch. Mc d, cc thut ng ny quan h vi nhau nhng chng khng hon ton ng ngha nhau [93].Nhiu thut ng tn ti trong lnh vc ny vi cch gii thch hi khc nhau v thng gn vi mt phng trnh hay mt c tnh vt l ring. Cng ng mch (arterial stiffness) c chn nh mt thut ng chung trong y vn ngy ny trnh nhm ln v m t bn cht n hi hay ngc li l cng ca thnh ng mch [79].Cng cn gii thch thm, cng ng mch (arterial stiffness) theo ngha mi ca thut ng m y vn th gii mun cp l hon ton khc vi x cng ng mch (arteriosclerosis) lu nay tn ti trong y vn Vit Nam. Cng ng mch (arterial stiffness) ch ni n s gim st kh nng co gin n hi ca ng mch m bt lun nguyn nhn g nm bn di cho d l x cng ng mch (arteriosclerosis), x va ng mch (atheros-clerosis), THA hay lng ng canxi thnh mch iu ny cn phn bit hiu r khi nim cng ng mch (arterial stiffness) ca y vn th gii.1.2.2. Nhng nh hng lm sng ca cng ng mch

Tng huyt p tm thu n c (HATT 140 mmHg v HATTr < 90 mmHg) v tng p lc mch l 2 biu hin lm sng ca gim kh nng co gin ng mch. T l THA tng dn theo tui, hn 60% ngi trn 65 tui b THA vi HATT 140 mmHg v/ hoc HATTr 90 mmHg; ngi da en ln tui c t l THA cao hn ngi da trng trong tt c mi nhm tui. Khng ging nh THA ngi tr, trong c HATT, HATTr v trung bnh u l yu t nguy c gy bin c tim mch; tng HATT n c cng nh tng p lc mch (ALM) v tng vn tc sng mch (PWV Pulse wave velocity) gy nguy c t qu, NMCT, suy tim v t vong chung cao hn ngi ln tui. S khc v c tnh nguy c gi c khc v c ch sinh l bnh THA ngi tr so vi ngi ln tui v c s khc nhau v phng php iu tr. Thc t, theo bo co c tng mi 2 mmHg HATT s tng nguy c t qu t vong 7% v bin c bnh MV t vong 5%. Tng huyt p trung bnh (HATB) mn tnh dn n dy thnh M ch yu trung mc. THA dn n ti cu trc thnh mch l c ch b tr lm bnh thng ha tc ng huyt p tng ln trn thnh mch. Ngc vi tc ng lo ha, s cng thnh mch ngi THA khc ngi bnh thng v ph i thnh do THA c th hi phc mt phn sau khi gim HATB . Tng sc khng mch mu ngoi bin, kt hp tng CM ngi cao tui dn n THA tm thu n c. iu quan trng, gim HA v/ hoc tng co gin thnh mch kt hp gim nguy c tim mch. Tuy nhin, kh phn tch tc ng ring ca can thip bng thuc v ca li sng ln gim HA so vi tc ng trc tip trn thnh mch. Bin i HATB xu hng tng quan tt bin i co gin M hn l bin i HATT. Cc th nghim lm sng v quan st cho thy gim HA lin quan gim nguy c tim mch gn lin gim CM, tuy nhin, khng nht thit phi nh hng trc tip thnh phn cu trc gp phn vo cng [31], [35], [63], [73], [88], [109], [115], [130]. 1.2.3. C ch, sinh l bnh ca cng ng mch

1.2.3.1. Cc thnh phn cu trc ca cng ng mch

Tnh n nh, kh nng phc hi, s co gin n hi mch mu ph thuc ng gp tng h ca hai protein l collagen v elastin. Lng tng i cc phn t ny thng n nh nh qu trnh chm (slow) nhng hot ng (dynamic) sn xut v gin ha. Ri lon cn bng do kch thch ca tnh trng vim, lm sn xut qu mc collagen bt thng v gim thiu elastin bnh thng, tng CM. Tng p lc ni mch hoc THA gy sn xut collagen qu mc. M bnh hc mch mu bnh bin i ch yu tng gp i n gp ba ln lp ni trung mc t tui 20 n 90, ph i lp c trn mch mu. Lp ni mc (intima) M cng, t bo ni m bt thng v ln xn, tng collagen, elastin try trt v t gy, nhim t bo c trn, i thc bo cng nh t bo n nhn v tng matrix metalloproteinase (MMP), yu t tng trng bin i , phn t bm dnh gian bo v cytokines. Bn cnh thnh mch dy ln, lo ha lm tng ng knh lng M trung tm (9% mi mi nm t tui 20-60 ca MC ln), mc d, nghin cu gn y gi iu ny nhng cha th kt lun cui cng [32], [57], [89], [142].Mng nn ngoi bo (extracellular matrix - ECM) thnh mch gm collagen, elastin, glycoprotein v proteoglycans. Nh , hai thuc tnh u tin l tnh ton vn v cu trc v tnh n hi c iu ha hiu qu bi cc enzyme metalloproteases d ha mng nn (matrix metalloproteases - MMPs). Thng qua tc ng gin ha collagen v elastin ca mnh, MMPs lm suy yu ECM do tho xon, gim collagen hiu lc v t gy elastin tng ng. Cc t bo mch mu v t bo vim nh i thc bo, bch cu a nhn trung tnh sn xut enzyme collagenases (MMP-1, MMP-8, MMP-13) v elastases (MMP-7 v serine protease). Suy thoi hn na mng nn ECM do tc ng ca tc nhn ha hc kch hot enzyme gelatinase (MMP-2 v MMP-9). Hot ng enzyme iu ha bi tng biu hin gen, hot ha sau chuyn i do phn ct cc protein tin MMP, do tc ng tng h gia MMP-MMP v bi plasmin, thrombin cng nh cc gc oxy phn ng (ROS). Cht c ch m ca MMPs chng li cc phn ng ny. Cht c ch m - MMP ca cn bng MMPs l trung tm kim sot ti cu trc. Lng ng chondroitin sulfate, heparin sulfate, proteoglycans v fibronectin lm dy v cng thm ECM [32], [52], [131], [142]. Collagen to bn cng gin thnh mch, c enzyme lin kt ngang ngay sau hnh thnh gip khng ha tan bi enzym thy phn. t gy lin kt ni phn t lm mt an nu nhau ca mng collagen. Hn na do tc thy phn chm, collagen d b lin kt ngang glycation (gn ng) khng cn enzyme. iu ny lm trng lng phn t collagen tng ln, km phn b cc si cha c t chc cao hn v mt chc nng. Phn t Elastin n nh cng nh lin kt ngang hnh thnh desmosine v isodesmosine. S t gy cc lin kt ngang lm suy yu mng elastin v khuynh hng khong ho ca canxi v pht pho lm tng cng mch. Hn na, s hot ha ca serine khc nhau v cc metalloproteases to ra cc phn t elastin b t gy v try tra. S thay i sn xut elastin v cc c ch chnh sa gp vo lm mt tnh n hi ca mch mu [32], [127], [142].

Cng M cng do cc sn phm cui glycation (ng hoa) bc cao (advanced glycation end products - AGEs), kt qu ca Glycation ha protein khng cn enzyme to lin kt cho khng th o ngc gia cc protein kt cu di nh collagen. Collagen lin kt vi AGE s cng hn v t chu nh hng bi chu trnh thy phn. iu ny dn n dn ng phn t collagen thiu ht v cu trc. Tng t nh vy, cc phn t elastin cng chu nh hng bi lin kt cho vi AGE lm gim mng lin kt n hi thnh mch. AGE cng nh hng chc nng t bo ni m bng dp tt (quencing) tng hp NO v tng to gc oxy ha nh peroxinitrite. Thng qua cc th th lin h Ig ca chng (RAGE), AGE tc ng to tn hiu v p ng vim, tng bc l p21 (ras), yu t nhn NF-B, hnh thnh gc oxy ha, cytokines tin vim, yu t tng trng v cc phn t bm dnh mch. Qua cc cht trung gian nh vy c th lm tng CM thng qua con ng MMPs, gp phn ri lon chc nng ni m lm tng trng lc c trn, suy gim th gin ni m do dng chy, gim phn ng vi chn thng mch, sinh mch v thc y hnh thnh mng x va. Phn ng tin x c kch hot c lp theo ng tt qua TGF- bi tc ng tng h gia RAGE vi phn t AGE [23], [32], [74], [106], [122], [136].

1.2.3.2. Vai tr ca t bo mch mu trong cng mch

CM chu tc ng mnh bi tn hiu t bo ni m v trng lc t bo c trn mch mu (VSMC). Trng lc VSMC thay i bi kch thch c hc, sc cng t bo v thay i tn hiu canxi v cht trung gian ni tit nh angiotensin II, endothelin, stress oxy ha v oxide nitric. Ri lon chc nng t bo ni m mt phn t mt cn bng gia NO v cc yu t i nghch ngun gc ni m, cc hormon gy co mch v oxygenases (v d, cyclooxygenase, NADPH v xanthine oxidase). Oxide nitric biu l gim st v tng biu hin cht c ch enzyme tng hp oxide nitric (oxide nitric synthase - NOS) nh dimethylarginine bt i xng lin quan n cng mch. Chc nng oxide nitric gim do hot ha gc oxy phn ng bi stress, hormon v c th c AGEs [34], [85], [126], [142].Gn y, cc nghin cu cng a ra iu ngc li tc cng mch lm thay i chc nng ni m v lm tng thm cng mch. Th nghim nui cy trong ng n hi cc t bo ni m sp xp th lp di tc dng dng chy mch p, kt hp ko cng v trt tng pha gy gia tng qu trnh phosphoryl ha ca Akt kinase serine-threonine v kch thch NOS ni m. Tuy nhin, khng c biu hin phosphoryl ha v cng nh khng c biu l NOS trn cc t bo ni m nui cy trong ng cng chu tc ng dng mch p tng t. iu ny cho thy thnh mch c ko cng c tc ng c hc truyn ln ni m su sc hn nhiu so vi ch c tc ng dng mch p n thun v s thiu co gin thnh mch lm suy gim hot ng NOS, dn n cng mch hn na [98].1.2.3.3. Vai tr ca Hormone v mui n

Angiotensin II (AII) kch thch sn xut collagen, tc ng ti cu trc mng nn v ph i thnh mch, gim tn hiu ph thuc oxide nitric, tng stress oxy ha v gim tng hp elastin. Ngoi ra, AII kch thch cc cytokine v cc yu t tng trng trong m lin kt gp phn tng p ng vim. Nhng thay i ny c chuyn i bi oxidase NADPH chu hot ha bi AII v khng kt hp NOS. Tng hp Aldosterone ch yu iu tit bi hot ng ca AII trn th th AT1, thc y cng mch v THA do kch thch ph i VSMC, x ha v fibronectin [44], [68], [127], [132].Mui n lm tng CM theo tui, khu phn n t mui ngi cao tui ci thin gin n M. Trong p ng vi mui n, cc thnh phn thnh mch b thay i vi tng ng k lp trung mc km ph i VSMC, sn xut nhiu collagen v elastin. Mui n tng tc vi a hnh thi di truyn v gen th th AT1, oxide nitric v tng hp Aldosterone. Suy chc nng ni m gim sn xut oxide nitric bi NOS, gim kh dng sinh hc ca oxide nitric v bi kch thch dimethylarginine khng i xng (ADMA), cht c ch NOS v tng hot ng Oxidase NADPH. Cui cng dn n kch thch ROS gia tng nh l mt c ch chung cho CM [22], [41], [59], [110]. 1.2.3.4. Glucose, Insulin v s cng mch

bnh nhn T v hi chng chuyn ha, CM tm thy trn mi la tui. Tng ng mu v insulin mn tnh gia tng hot ng ti ch ca h renin-angiotensin-aldosterone (RAA), bc l th th angiotensin I trong m mch mu, thc y ph i thnh mch v x ha. Tng insulin mu c tc ng tng sinh, v khng insulin lm suy yu tn hiu ph thuc PI 3-kinase chu trch nhim v tc dng chuyn ha nhy ca insulin. Hot ng cc mitogen kch thch tng trng theo con ng kch hot kinase vn cn tng i c bo v. Suy gim dung np glucose gy tng gn ng ln cc protein khng cn enzyme, lin kt cho cc collagen v lm thay i tnh cht c hc m k thnh mch. CM tip tc tng nng hn do ri lon chc nng ni m do tng cao LDL, axit bo t do, endothelin-l, tc ng gin mch khng ca insulin hoc mc thp adiponectin v peptides li niu. Quan trng hn, tng CM hi chng chuyn ha khng phi hu qu T m do bt thng chuyn ha v hormon tinh t biu hin kh sm vo giai on u ca khng insulin [33], [56], [105], [114].1.2.3.5. Bnh thn mn tnh

Cng mch bnh thn mn do mt s c ch nh: dy ni trung mc v tng THA, tng collagen mng nn, tng sinh VSMC do hot ha h RAA ti ch v ton th. Hn na, gim tnh n hi v kh b thoi bin ca collagen cng nh cc protein ECM khc do hnh thnh AGE v phn ng vi methylglyoxal, cc hp cht phn ng cacbonyl khc tng ln bnh nhn tng ur mu. Cng M cn do khuch tn vi ho o trong M khng do phn ng vim. Cc t bo ging nh osteoblast tit protein mng lin kt ca xng [18], [43], [90].1.2.3.6. Di truyn hc ca cng mch mu

S tham gia ca nhiu protein v cc hormon trong cng mch mu th r rng khng ngc nhin g khi tinh cht a hnh thi di truyn c xc nh trong lin quan n tnh trng tng CM [32], [67].

1.2.3.7. Sinh l bnh cng ng mchCM lm m rng khong ALM nh hng su sc n mch mu v sinh hc tim. Trong M, cc bin i do tc ng c hc ch yu lin h ti s va p ln mch mu do lan truyn mch v p lc tng. Vng quanh ch chia i mch mu c nhiu dng chy ri v nm tri cng cao hn ca tc ng lan truyn dao ng vi mc tc ng nng hn, khuch i ri lon chc nng ni m v bnh mch mu. M mm mi, ti mu dng mch p tng lm tng gin mch, bin i h qu do tng sn xut NO cng nh kch hot knh K+ nhy cm canxi lin quan yu t cng phn cc (hyperpolarizing) ngun gc ni m. iu ny khuch i ging mch gin ra thm na khi ALM tng kch thch knh K+ nhy cm ATP ti ch, c ch thng thng quyt nh dng chy cc b trong MV v mch mu ngoi vi. Tuy nhin, gia tng dng mch p cn gin n (distensibility) mch bnh thng, v gim co gin thnh mch s chn tn hiu quan trng lin quan n p ng ny. i vi tim, cng mch nh hng hu gnh tht tri, hiu sut tng mu tim v ti mu chnh bn thn tim. Khi M cng, HATT cao hn vi cng mt th tch tng mu do tim bp so vi M bnh thng. Hu qu tng hu gnh lm tng nhu cu nng lng c tim, lu dn gy ph i c tim thm ch ngay cng mc HATB. Cng mch cng thay i dng thc ti mu tim. Mch vnh nhn mu ch yu k tm trng, do vy thay i trong HATT tc ng tng i t v ti mu trung bnh. Tuy nhin, tim tng mu vo MC cng, ti mu vnh cho thy dng tm thu kh di do lin quan ti HA ti mu tm thu tng cao. iu ny lm hot ng bp ca tim b gim st. Khi bin c thiu mu cc b cp, dng vnh nhy cm hn nhiu vi s suy gim chc nng tm thu hn ch khng phi cch thc khc (chc nng tm trng). iu ny c chng minh thc nghim trn ch, trong tim tng mu ngu nhin trc tip vo MC gin n bnh thng hoc mt ng cng (ct MC ni vo mt on ng cng). Tim tng mu vo ng dn cng c bin co gin bung tim ln hn v s nh tr tim (cardiodepression) xy ra sm hn khi lm tc vnh cp so vi tim tng mu vo MC mm mi mc d mc tng ng v nhu cu chuyn ha tim c bn [32], [95], [98], [142].1.3. PHNG PHP NH GI CNG NG MCH

1.3.1. nh gi cng ng mch khng xm nhp

1.3.1.1. Cng ng mch vng hay mt on ng mch

Vn tc sng mch (Pulse Wave Velocity - PWV)Sng p lc mch sinh ra v lan truyn n ngoi bin vi tc khc nhau ty thuc bn cht phn on M. M cng, PWV lan truyn nhanh hn. Cc yu t quyt nh PWV l tnh n hi thnh M, hnh thi hc M cng nh nht mu. Mons-Korteweg gii thiu phng trnh xc nh PWV nh sau: PWV = [(E.h) / (2r.)]; E l Modun n hi ca Young, h l dy thnh mch, r l bn knh v l t trng mu [69].

PWV cn c tnh bng o thi gian truyn sng mch gia u xa v u gn ca on M v khong cch gia hai im o. Sng mch trong tng M (cnh, i, quay v ng mch chy) c th ghi khng xm nhp bng nhiu loi cm bin khc nhau hoc bng u d doppler lin tc. Thi

gian truyn sng mch l thi gian tr gia sng mch u gn v u xa xc nh bi phng php o chn n chn (foot-to-foot) hai chn sng p lc hai v tr o. Chn sng mch l im HA tm trng ti thiu hoc nt bt u hng ln ca p lc tm thu sng mch. Khong cch gia hai im ghi o trn b mt c th bng thc dy. Khong ny khng l khong cch ng ca sng mch i, ch l mt c tnh thi. Cch ny c th nh gi qu cao khong cch sng truyn ngi bo ph v thp khong cch ny bnh nhn MC quanh co. PWV c tnh (Hnh 1.3) vi thi gian truyn sng mch (t) v khong cch (L) nh sau [69], [118], [141]:PWV (cm/s hoc m/s) = L /t.

Mt trung bnh khong 10 nhp p lin tip hoc s nhp p trong khong 10 giy c nh gi cho mt s chu k h hp. PWV c th c o ti a im khc nhau: 1) PWV cnh-quay, t ng mch cnh n ng mch quay; 2) PWV i-chy, t M i chung n M chy; 3) PWV cnh- i, t M cnh n M i chung; 4) PWV cnh tay-mt c chn, t M cnh tay n M chy [55].

Tin b cng ngh gn y cho php o PWV cc vng khc nhau d dng. H thng Complior (Artech Medical, Pantin, Php) o PWV t ng vi cm bin p trc tip ln da, thu sng mch t hai im cng mt lc. Thit b ny dng rng ri trong cc nghin cu dch t hc, cung cp thng tin d bo ca PWV cho bin c tim mch. H thng SphygmoCor (AtCor, Sydney, Australia) dng o sng mch tun t ti hai im v thi gian truyn sng mch c tnh bi bt u t nh sng R in tm ghi km theo. Thi gian truyn sng mch gia hai im l hiu s thi gian gia nh sng R v chn sng mch u xa vi thi gian gia nh sng R v chn sng mch u gn (hnh 1.6) [69]. Trng lc mch k vi trung thc cao (Millar) c dng ghi li cc sng mch. Thit b ny cng c th o huyt p MC trung tm v ch s gia tng. VP-1000/2000 (Colin Co, Komaki, Nht Bn) l thit b duy nht o PWV cnh tay-mt c chn. Sng mch t M cnh tay v M chy thu c vi cm bin hng ngoi tch hp trong bng qun o HA bc quanh cnh tay v c chn. Thit b ny cng o PWV MC trung tm (PWV tim - M i) v PWV ngoi vi (M i, mt c chn) vi cc nhn cm trng lc mch. Kt qu mt s nghin cu nh ch ra PWV cnh tay-c chn l mt d bo c lp ca t vong tim mch v bin c tim ngi cao tui trong qun th cng nh bnh MV. Mc d, gi tr ca PWV cnh tay-mt c chn d on bin c tim mch c hn ch, PWV ny l d o nn c tim nng ng dng trong sng lc [103], [104], [128], [141].

1.3.1.2. Cng ng mch ti chS gin n (Distensibility), co gin (Compliance) M biu hin mi quan h gia bin i thun ty hay tng i dung tch M do bin i p lc gin mch. Thc t, gin n mch tnh nh sau (hnh 1.7) [69]:

Gin n mch (Distensibility- D) (Pa-1 hoc mmHg-1) D= A / (A PP) = (Ds2 Dd2) / Dd2 PP = (2D Dd + D2) / Dd2 PP. A khc bit din tch ct ngang tm thu v tm trng M, PP la ALM, Ds v Dd ng knh M ti a, ti thiu theo p lc v D khc bit ng knh tm thu v tm trng. Dd ng knh M cui tm trng.

Co gin M l biu hin bin i thun ty trong dung tch M cho mt n v bin i p lc (trn c th sng gi nh chiu di mch l khng i trong k tim tng mu) v c tnh:Co gin k hiu C (cm2/ mmHg hoc m2/Pa) = A / PP

= (Ds2-Dd 2) / 4PP = (2.D Dd + D2) / 4PP.

M un n hi Young l mt ch s khc ca CM, o cng thnh M. M un n hi c tnh ton da vo thay i ng knh lng M v dy thnh M th hin nh sau: M un n hi E (mmHg/ cm hoc Pa/ cm) = (PP x D) / (D h)

Trong h l dy thnh M. M un n hi Young l t s sc p trn sc cng thnh M, o cng ni ti thnh M. CM lin kt cht ch vi HA. Biu thc gin n v co gin M l hm s ca HA [69]. kho st CM c lp vi HA, ngi ta dng ch s cng mch beta (). y c mt hiu chnh ton hc cho tc ng HA. V cng knh, hiu chnh ton hc ny thng t c dng. Tuy nhin, ch s cng beta () tng i c lp vi thay i HA nht thi, bng s dng mt chuyn i lgarit ca t l HATT v HATTr l d hn cho s dng: [55].= [ln (SBP/DBP) D]/ D; vi SBP l HATT v DBP l HATTr.

Siu m thng dng cho o ng knh M. Loi siu m tt nht cho vic o ny l phng php theo di m di vi u d dng tn s radio hoc u d Doppler pht hin di chuyn ca thnh gn v xa ca M. Tuy nhin, phng php ny qu t v cha thc t cho p dng lm sng. Kiu siu m B-mode c th c dng vi u d ghi hnh nh t ng. ng knh M tm thu v tm trng o bng tay t hnh nh B-mode nh thc o in t cng vi s gip ca ECG. Vn khc l HA cn cho tnh ch s CM. Hu ht cc nghin cu s dng HA cnh tay khi nh gi cng MC v cnh. iu ny phi xem rng HA ca MC v cnh tng t nh M cnh tay. Tuy nhin, HA thay i dc theo cy M. HATT ca M ngoi vi cao hn M trung tm n hi (M ch v cnh). Thng nh gi HA M cnh v ch bng trng lc mch k qua u d chc nng ring. Mt khc c c khng khi o CM ti ch m dng phn nh cng cc M khc, hin vn vn cha c gii quyt [55], [102].

MRI cng dng cho o gin n MC. gin n MC ngi khe mnh nh gi bng MRI cho thy ln nht MC ln tip theo l quai MC, ri n u gn MC xung. Nhng MRI qu t v khng thc t cho thm khm thng thng [55]. 1.3.2.3. Cng ng mch h thng (Systemic arterial stiffness)Co gin ng mch h thng (Systemic arterial compliance)Co gin ng mch c nh ngha l mi quan h gia s bin i v th tch vi mi n v bin i p lc mch. Mt trong nhng phng php c dng o co gin M h thng l "phng php din tch" th hin nh sau:

Co Gin M h thng = Ad / [R (Ps-Pd)], trong Ad l phn din tch di ng cong p lc mch k tm trng (t cui tm thu n kt thc k tm trng), R l tng tr khng ngoi vi, Ps HA MC tm thu v Pd HA MC tm trng (Hnh 1.8). Dng sng p lc gc MC rt ra t sng M cnh bng trng lc mch k trc p ln u gn M cnh phi. HATT trung tm ly t hiu chnh p lc thu c bng trng lc mch k so vi HA cnh tay o cng thi im. Tng khng ngoi bin c tnh l HATB chia cho lu lng dng mu trung bnh. Tc dng chy lin tc ca MC ln c th o vi tc k dng Doppler t trn hm c. Khi lng trung bnh dng chy l tch s ca dng tm thu trung bnh nhn bi din tch gc MC o bng siu m [76]. Phng php khc n gin l t s ca th tch tng mu chia cho p lc mch p nh sau: Co gin h thng = SV/ P, vi SV l th tch tng mu v P l hiu p. V c tnh chnh xc th tch tng mu l kh khn, gi tr d bo ca SV / P b hn ch trong nghin cu [55].

Co gin M h thng theo sc cha C1 (M ln) v theo dao ng C2 (M nh) tnh bng phn tch sng mch v m hnh Windkessel b sung (phn tch k mch tm trng). Cm bin trng lc mch t vo M quay v mt cm bin giao ng t M cnh tay bn kia. Phn tch k mch cn o c c hai chc nng dung cha (capacitive) ln s dao ng (oscillometric). S dng k mch lng gi hot ng (dung cha) M ln v dao ng ca M nh, i din cho ngun s cp ca sng phn x hay s dao ng trong h M. Tuy nhin, tnh chnh xc ca co gin ly t m hnh Windkessel b sung cn b nghi ng, iu ny do s khc bit trong co gin M cnh tay v chn chu nh hng mnh c tnh tun hon vng. Gi tr d bo ca co gin M h thng hin cha xc nh [55], [79].

Phn tch k sng mch (pulse wave contour Analysis)Ch s gia tng (Augmentation Index AIx)

Phn tch dng sng mch M trung tm (MC, cnh chung) c th cung cp thng tin v CM h thng. Cc dng sng mch trung tm chu nh hng khng ch bi cng cc b (trung tm) m cn bi cc tnh cht n hi ca ton b mng M [19], [69], [138].

Sng p lc M gm sng pht sinh t tng mu tht tri v sng di li t ngoi bin. Tng cng MC s tng PWV trong MC; trng hp ny sng di v gc MC sm trong k tm thu mun khi tm tht vn cn tng mu, kt hp sng di vi sng pht lm gia tng HATT trung tm. Tng HATT trung tm v ALM lm tng sc cng thnh M, tin trin ca x va M v ph i tht tri do tng hu gnh. S tr v sm ca sng phn hi gy gim HATTr trung tm dn n gim ti mu MV. Ch s gia tng (AIx) l thng dng v n gin o tc ng ca phn hi sng. AIx c tnh nh sau: AIx (%) = (P / PP) 100P l huyt ap gia tng hay chinh la s khc bit gia huyt p tm thu v p lc ti im un m chnh l im khi i ln ca sng p lc di v PP l ALM (hnh 1.9). nh tm thu th hai l vai ca sng mch v nh u tin l im ti a ca p lc tm thu trung tm. xc nh tc ng ca sng phn hi trn tm tht tri v MV, AIx nn tnh t sng p lc ca M trung tm, tc l MC ln hay mch cnh [55], [69], [79].

Ghi sng p lc MC ln xm nhp s khng thc t cho s dng lm sng. Gn y, sng p lc MC ly ra t sng p lc tm thu M b mt nh M quay hoc M cnh bng s dng u d chc nng. Sng p lc M quay ghi vi trng lc mch k ri sng p lc MC rt ra bi chc nng tng qut ha ca u d (h thng SphygmoCor, AtCor, Sydney, c). Ghi sng p lc M quay c chung hn v M quay c xng quay nng cho php ghi c sng p lc ti u. Ghi sng p lc M cnh kh hn, i hi chuyn mn cao cho d u d chc nng cha cn thit dng v M cnh gn MC nn dng sng s tng t. Vic o ny kh khn khi bnh bo ph v hp cnh. Mc d, AIx MC rt t sng p lc M quay c dng ph bin nh l mt ch s cng MC. chnh xc ca chc nng tng qut ha ca u d ang c t ra. C bo co khng c mi quan h gia AIx MC trung tm v AoPWV, nn AIx MC v AoPWV khng dng thay th cho nhau nh l mt ch s ca cng MC. Cng cn thm nh s chnh xc khi ly sng p lc trung tm t sng mch quay nh chc nng tng qut ha ca u d [50], [111].

1.3.2.4. Mt s phng php khc nh gi cng ng mchPhn tch sng mch th tch s ha

Sng mch th tch s c th c ly t ngn tay vi mch tch cm quang hng ngoi (infrared photoethysmography). Bn sng trong tm thu (a, b, c, v d) v mt sng trong tm trng (e) thu c t ngun gc th pht ca dng sng p lc. T l chiu cao ca cc sng d v sng a (d / a) lin quan n tui v HA. T b / a tng vi tui, t c / a, d / a v e / a gim vi tui. T nhng kt qu ny, Ch s lo ha c nh ngha nh sau (Hnh 1.10)

Ch s lo ha (Aging Index AgI) = (b-c-d-e) / a. Tuy nhin, PWV MC c bo co l mt du hiu tt hn cho s hin din ca bin i x

va M hn l so vi ch s lo ha [55].

Ch s cng mch lu ng (Ambulatory)HA lu ng 24 gi thng dng trong thc hnh lm sng. Ghi HA 24 gi cho php tnh dc hi quy ca HATTr trn HATT. nh ngha ca ch s CM lu ng (Ambulatory arterial stiffness index AASI) nh sau: AASI = 1 - (h s gc hi quy ca HATTr/ HATT). AASI l tng quan ng k vi PWV (r= 0,51) v AIx trung tm (r= 0,48) [55], [70].Hin nay do tin b ca nhiu phng tin k thut, cng ngh thng tin v da trn c s sinh l hc v huyt ng h M, h tun hon m ngi ta tin hnh nhiu bin php v cc ch s nh gi CM khc nhau. Bng 1.1 Bng tm tt cc ch s cng mch [32], [69] Tn ch sCch tnhCng c hay dng

p lc mch PP = Ps Pd (mmHg)Huyt p k

Modun n hi Ep* Ep = PP.D/D (mmHg)Siu m, MRI

Modun Young E* E = PP.D/D.h (mmHg/cm)Siu m, MRI

Gin n mch* D = D / D.PP (1/mmHg)Siu m, MRI

Co gin (Ct ngang)* C = D /PP (cm/mmHg)

hoc C = A / PPSiu m, MRI

Vn tc sng mch* PWV = L/t (m/s)Sng p lc

Siu m, MRI

Ch s gia tng AIx* AIx = P gia tng/ALM (%)Sng p lc

Ch s cng mch * = Ln(Ps/Pd)/[(Ds-Dd)/Dd]Siu m

* i hi o huyt p ti ch

1.3.2. nh gi cng ng mch xm nhp

Kho st CM, hai thng s cn l HA ti ch M kho st vi bin thin kch thc M tng ng. o HA xm nhp ng nhin l tiu chun vng ca nh gi HA. Vn quan trng l cn nm r k thut c kt qu ng. V kch thc M bin thin s c c t chp nhum M c thuc cn quang gip c c thng s kch thc cn kho st.

1.3.2.1. o p lc mch mu xm nhp

Nguyn l hot ng

Nguyn l hot ng h thng o p lc xm nhp (ALXN) kh n gin. p lc trong lng mch tc ng trc tip ln mng nhn cm ca b chuyn i (BC) s c chuyn thnh in p v c ghi nhn li trn mn hunh quang hay k thut s di dng sng dao ng iu ha. Gi thnh cao cng nh tnh phc tp ca h thng c b tr bng vic s dng thun tin, chnh xc cao v nht l c th theo di tnh trng huyt ng bnh nhn lin tc. V vy o ALXN l mt phng tin theo di khng th thiu trong hi sc bnh nhn nng, l tiu chun vng theo di huyt p trong phu thut tim mch [47], [58], [113], [134].Cc b phn ca h thng o ALXN

Catheter hay ng thng.

H thng dy ni, kha 3 nhnh v thit b bm lin tc 1-3 ml/gi.

B chuyn i (transducer): chuyn bin i p lc c hc thnh nhng bin i v in p.

Ghi nhn trn mn hnh nhng thay i in hc k trn.

H thng tng ra (flush systems).

ng thng (catheter)

Trong thng tim, ngi ta thng dng ng thng c 4F - 6F nn vi c ln nh vy kt qu o ALXN cng chnh xc hn. V li, ch thao tc trn bnh nhn trong mt thi gian ngn nn t c tai bin to huyt khi trong lng mch. Cht liu thng dng l Teflon lm cho ng thng mm v t to huyt khi.

H thng dy ni

Gm dy dn, kha 3 nhnh v thit b tng ra lin tc.

B chuyn i

BC chuyn nhng thay i p lc c hc thnh thay i v in p. BC hin nay dng mng silicone gn nhng cht cm nhn sc khng.

Ngi ta sn xut BC vi hiu in th 5 microvolt, trong mt milimet thy ngn kch thch mt vn (volt). V vy v l thuyt, BC c th s dng cho mi my theo di (monitoring). Cc BC hin i loi b nhng kh khn khi phi lun chnh li im khng (0).H thng phn tch v hin hnh (monitoring)

Cc thit b hin i dng h thng vi tnh x l phn tch v ghi nhn cc thng tin p lc. Chng ghi nhn cc ng cong thay i p lc, cc gi tr p lc tm thu, tm trng, trung bnh, chc nng bo ng, lu tr d liu, chc nng in. Cc thut ton v phn mm dng phn tch thng tin p lc v cung cp d liu bng s thay i gia my ny v my khc.

H thng tng ra (flush systems):

trnh huyt khi lng mch v kt qu ghi nhn chnh xc hn [47], [58], [113], [134]. B chuyn i c in (transducer)

S thay i p lc trong lng mch c ghi nhn bng nhng sng dao ng iu ha phc hp. Nh vt l hc ng thi cng l nh ton hc Fourrier tm ra phng php gim phc tp khi phn tch sng vt l c chu k lp i lp li theo thi gian. Sng p lc trong h tun hon cng l loi sng c chu k phc tp nu trn. Theo Fourrier, tt c cc dng sng phc tp c th phn thnh mt lot cc dao ng cn bn m mi dao ng c tn s l bi s nguyn ca sng cn bn. Hay ni cch khc, sng phc hp ny c din t nh s kt hp ca mt lot nhng sng hnh sin n vi bin , bc sng, tn s v pha khc nhau, trong c mt sng cn bn v mt lot nhng sng dao ng phi hp khc.

Hnh 1.12 Sng sin n [58]

Hnh 1.13 Hai sng sin vi bin v tn s khc nhau [58]

Hnh 1.14 Sng hp ca hai sng trn [58]Trong h thng o HA xm nhp, sng phc hp c phn tch bi mt b vi x l thnh ra nhng sng hnh sin thnh phn, ri c xy dng li t sng nn v tm hay hn nhng sng ha hp vi n c tn s cao hin th chnh xc sng nguyn bn. H thng o HA xm nhp phi c kh nng truyn v pht hin ra nhng thnh phn tn s cao ca sng huyt p (t nht 24 Hz) hin th sng p lc M chnh xc. y l iu quan trng cn ghi nh khi xem xt tn s ring ca h thng [47], [58], [113], [134].

Nguyn l hot ng ca b chuyn i

chnh xc BC chuyn i nng lng c hc thnh nng lng in hc l mt trong nhng yu t chnh cn thit to ra chnh xc dng sng p lc. BC l tng s chuyn hon ton nng lng nhn vo thnh nng lng i ra [58].1.3.2.2. nh gi cng ng mch vng xm nhp

nh gi cng ng mch bng vn tc sng mch ng mch ch (MC). Vn tc sng mch (PWV - Pulse Ware Velocity) on MC ln - ng mch i c xc nh bng phng php xm nhp kt hp ngay trong lc chp ng mch vnh (MV) nh b phn bn t ng i km theo my DSA Phillips mt bnh din cho php ghi in tim vi ghi p lc ng mch xm nhp tun t ti hai v tr ng mch ch ln v ng mch i chung km theo phn mm tnh thi gian truyn sng phn tch nh trn hnh minh ha. Chng ti tnh thi gian theo cch o t chn phc b QRS ca ECG n chn sng p lc mch (phng php foot to foot) ca 3 bc sng lin tip sau cng li v chia trung bnh ta s c c thi gian truyn sng T ti mt v tr o. T1 l thi gian truyn sng p lc mch ti MC ln v T2 tng t l thi gian truyn sng p lc mch ti ng mch i. Nh vy thi gian truyn sng p lc ng mch gia on MC ln v M i chnh l dT = T2 - T1(hnh 1.16). Khong cch gia hai im ghi ti MC ln v M i (L) c xc nh bng hiu s chiu di phn ngoi c th ca catheter o p lc xm nhp khi ghi lu p lc ti i tr i chiu di ca catheter khi ghi ti MC ln. o chiu di catheter bng thc dy t nh ng t lng mch n ui catheter. PWV xc nh bng cng thc c in khong cch chia cho thi gian. Nh th, PWV MC ln-i c tnh theo cng thc [64], [79], [83]:PWV = L/ (T2 T1) = L/dT (m/s)

Mt phng php khc xc nh vn tc sng mch xm nhp khng ghi p lc tun t m ghi ng thi ti hai v tr. Khi mt ng p lc ghi ti MC ln qua catheter pigtail 5F v mt ng ghi ti M i qua cnh tay bn ca ng t lng mch 6F (sheath) nh hnh 1.17.

nh gi vn tc sng mch xm nhp c u im o c khong cch tht on MC m sng mch truyn qua thay v o gi nh on M cnh-i bn ngoi c th. V mt thi gian truyn sng mch gia hai phng php xm nhp v khng xm nhp theo nghin cu ca Thomas Weber v cs c tng quan cht ch r = 0,8, p < 0,0001 [135].1.3.2.3 nh gi cng ng mch ti ch xm nhp

nh gi cng ti ch phi cn hai thng s l huyt p o ti ch M cn nh gi v ng knh M o cng mt ch. Huyt p gc MC ln o xm nhp trong thng tim. Thng s v ng knh c c t kt qu chp bung tht hay chp nhum gc MC vi thuc cn quang.

So snh gia phng php xm nhp khi thng tim v khng xm nhp qua siu m nh gi gin n MC ln c C. Stefanadis v cs nghin cu t 1990. ng knh MC tm thu v tm trng o bng hai phng php cho thy khng khc bit c ngha thng k, tuy nhin o huyt p xm nhp ti MC ln v khng xm nhp bng huyt p k qun cnh tay th li c s khc bit c ngha thng k [120].1.3.2.4 nh gi CM h thng hay ch s gia tng xm nhpVic nh gi nay tng t nh phng php khng xm nhp. Khc bit chnh l dng sng gc MC ln hay dng sng p lc trung tm thu c bng o p lc xm nhp ngay trn van MC bng ng thng pigtail 5F, khng phi sng p lc trung tm t mch quay qua hiu chnh bng chc nng u d c bit. Phn tch thng s ny tin hnh bn t ng hay t ng ty thuc phn mm tnh huyt ng nh km trong h thng chp vnh cho php [83].1.4. TNG HUYT P V CNG NG MCHCc mch mu n hi (ng mch) tr nn cng hn l mt qu trnh lin quan vi tui v c gia tng ln do THA. THA c th to CM v c

hai phng din chc nng v cu trc. S cng mch c kh nng hi phc cp thi v ko di ca MC ngc v cc nhnh ca n xy ra khi mc HA M tng ln. Ngi tr THA tng sc khng xui dng tiu M, gy nn p lc gin mch tng truyn ngc li trn M n hi trung tm. iu ny lm cho mng n hi ang chu ti ca M ln b cng ra thm v tr nn cng hn. THA theo thi gian dn n ti cu trc mch mu, ph i v tng sinh thay i cu trc lm x cng chnh bn thn cc M ny. THA ngi tr thng biu hin vi HATTr cao trong cc dng tng HATT v TTr hoc tng HATTr n c. Ngc li, tng HATT n c ca ngi gi, lin quan vi tng HATT v gim HATTr, thng biu hin vi ALM m rng l du hiu ca tng CM. CM thng thy nhng ngi cao tui vi tng HATT l c trng bi t gy cc protein elastin, tng sinh collagen v lng ng canxi thng xuyn gn vi gin rng MC. Khi cc M ln gin, cng thnh v tc ng mch p tng, lm trm trng thm thoi ha thnh M, do bt u ngay mt tc ng phn hi dng m theo THA dn n tng thoi ha hn na [39], [77].Nghin cu Framingham cho thy nhng ngi bnh khng c iu tr tc THA t l vi tng cng M ln v do ko theo mt vng lun qun ca THA v tng thm cng ng mch ln. Ngi trung nin v ngi cao tui THA khng iu tr c nhiu kh nng biu l cc du hiu lin quan n tui do tng HATT v gim HATTr so vi chng HA bnh thng. Benetos v cng s pht hin ra rng hng nm t l tin trin ca vn tc sng mch (PWV) trn bnh nhn c theo di iu tr THA cao hn so vi cc i tng HA bnh thng, cho thy tin trin nng ln ca CM trn i tng THA d c iu tr. Ngoi ra, cc nh iu tra cn thy rng HA ng mch trung bnh, biu hin sc khng ngoi vi, khng tng trong sut 6 nm theo di nhng PWV th tin trin ln gp 3 ln v kh kim sot hn nhiu so vi vic kim sot tt mc THA. V vy, c hai nhm nghin cu Framingham v Benetos cng cs nhn thy h qu iu tr khng thng xuyn hoc khng c iu tr, THA s dn n tng tc CM ln theo tui - mt thc o ca lo ha mch mu [26], [39].Thng thng, CM l hu qu ca THA ch khng phi l nguyn nhn ca n, nhng c bng chng rng mi quan h gia THA v CM theo hai chiu thun nghch. Nm 1999, Liao v cng s t nghin cu nguy c x va M trong cng ng (ARIC) ngi trung nin (tui 45 n 64), s dng siu m B-mode vi phn gii cao kim tra M cnh chung tri, thy rng c tng 1 lch chun ca CM cnh lin quan ti tng 15% nguy c mc THA trong tng lai, c lp vi cc yu t nguy c thng thng v mc ca HA. Cng vn ny, Dernellis v Panaretou xc nhn nhng pht hin ca Liao v cs nhng cn m rng tui t 35 n 93 tui. CM ch xc nh bng siu m tim M mode bi k thut phn tch hi quy a bin, o ng knh MC tm thu, tm trng v dng cc phng trnh tiu chun tnh ch s cng, gin n (distensibility) v ch s cng MC. Tin trin t ngi HA bnh thng n THA c lin quan n tui, gii v t l tin trin ny sau bn nm theo di thp nht ph n tr (4%) v nam gii tr (11,5%), cao nht ph n ln tui (26%) v nam gii ln (59%). Dng m hnh hi quy tuyn tnh a bin, h pht hin cng MC ngi HA bnh thng d on THA trong tng lai sau khi iu chnh cc yu t nguy c bao gm HATT, tui, gii tnh, BMI, nhp tim, cholesterol ton phn, T, ht thuc l, tiu th ru v hot ng th cht. Nhng kt qu pht hin ny c ghi nhn cho cc i tng tr, gi v cho c hai gii. [37], [75], [119].

Bo co ny t ra nhng cu hi ng c quan tm. Lm th no CM lin quan n THA? N tht s l yu t nguy c hay ch l du hiu nguy c? Mt yu t nguy c tht s b nghi ng l nguyn nhn ca qu trnh bnh. Mt du hiu nguy c s ch kt hp vi qu trnh bnh m khng cn nm trong con ng nhn qu. Hu ht, cc nghin cu nh gi CM v THA l nghin cu ct ngang nn rt hn ch kt lun v nguyn nhn mt cch ng tin cy. Nghin cu ct dc ca Dernellis v Panaretou ch ra tng CM tim n nguy c v sau, l tin cho s pht trin ca THA. Nhng pht hin ca Dernellis v Panaretou cng nh ca Liao v cng s cng vi cc nghin cu trc y cung cp h tr cho CM v THA trong mi tng tc thun nghch theo hai chiu. Cc nghin cu ny s kch thch nhng nghin cu tng tc ca cc gen, kiu hnh tc thi v cc yu t mi trng tin cho tng tc lo ha mch mu v THA. Hn na, chn on sm CM vi cc k thut khng xm ln trc khi s pht trin ca THA hoc cc bin chng tim mch c th xc nh ngi c nguy c vo thi im cn phi can thip li sng c th c xem l iu tr hu ch [37], [39], [75].1.5 CNG NG MCH V BNH NG MCH VNH

Cc vn sinh l bnh lin quan gia hai bnh ny hin vn cn thiu, cn ang c tch cc nghin cu lm r. Nhng d liu cho n nay phn ln l cc kt qu nghin cu chng minh hu qu bnh tim mch ni chung v bnh mch vnh ni ring do cng ng mch ln gy ra. Nhng nhn thc ban u v vn ny xin c trnh by s lc di y.Cng ng mch ln c th l nguyn nhn v cng l hu qu ca x va ng mch v lin quan c lp n hu qu bnh ng mch vnh. Mi quan h ny c th l quan h nhn qu do nh hng bt li ca cng ng mch ln trn huyt ng mch vnh. Cng ng mch ln c lin quan vi bnh mch vnh, thiu mu cc b c tim v t vong do bnh ng mch vnh. Mi quan h lin kt gia cng ng mch ln v bnh ng mch vnh khng n gin v c kh nng hai chiu. Cng ng mch c th c hai l nguyn nhn v hu qu ca x va ng mch. Tuy nhin, bt k c ch no, r rng l cng ng mch ln lm trm trng thm cc triu chng thiu mu cc b ca bnh ng mch vnh. Mi quan h gia cng ng mch v t vong do bnh ng mch vnh c kh nng l quan h nhn qu. C th tm lc c ch quan h gia hai bnh ny nh hnh sau [65].

Hnh 1.18 Cng ng mch v bnh MV [65]1.6 CC NGHIN CU TRONG V NGOI NC LIN QUAN1.6.1. Nghin cu trong ncTc gi inh Th Thu Hng (2008) nghin cu trn 123 ngi Vit Nam khe mnh trung nin vi tui 51,2 13,9 bng phng php khng xm nhp Complior thy vn tc sng mch cnh i l 10,2 1,6 m/s v tng quan thun vi tui r= 0,56 p 180

> 14090 - 99

100 - 109

> 110

< 90

Chn on bnh nhn THA nguyn pht da vo khm lm sng. Nu lm sng c gi nguyn nhn THA chng ti s lm thm cc xt nghim cn thit khc chn on loi tr. c bit trong ti ny i vi bnh nhn THA c km bnh T th phi c tin s THA r rng trc khi pht hin bnh T mi c chn (trnh THA th pht do T).

2.1.3. Xc nh bnh nhn khng THA

L cc bnh nhn c tr s huyt p lm sng tm thu < 140 mmHg v/ hoc tm trng < 90 mmHg.

Khng c tin s THA v khng ang dng thuc h p.

2.1.4. Tiu chun chn bnh MV v khng bnh MV

Bnh nhn bnh MV phi c hp ng knh ti thiu mt trong cc

nhnh MV chnh vi khu knh tn thng hp 50 % (loi nu < 50%).

Ngi khng bnh MV l ngi c chp vnh v c kt qu khng hp ( hp 0%) trn bt c nhnh MV no.2.1.5. Tiu chun loi tr

- xc nh hoc nghi ng THA th pht.- THA cn iu tri cp cu (e doa bin chng, THA c bit cao > 220/120 mmHg, THA nng vi bnh vong mac III-IV) ma khng kim sot c [9].

- Bnh tim bm sinh, bnh van tim v ri lon nhp tim.

- NMCT cp, suy tim, suy thn nng, suy gan nng.

- Cc bnh mn tnh (Phi, ton th).

- Bnh v mu, bnh c tnh.- Hoc khng chp nhn tham gia nghin cu.

2.2 PHNG PHP NGHIN CU2.2.1. Thit k nghin cu

Tin hnh nghin cu ti thi im bnh nhn trc chp vnh v trong chp vnh nu cn kim tra li sau chp vnh.

Phng php: tin cu, m t ct ngang, c so snh i chng.2.2.2. Cc phng php nghin cu c th

Mi bnh nhn c kho st theo phiu nghin cu vi quy trnh sau: Tin hnh hi tin s, bnh s, khm lm sng t m chn la i tng nghin cu t tiu chun quy nh.

Cc xt nghim sinh ha mu c ly m bo ng quy trnh, cc th thut thm d c tin hnh v phn tch ti cc trung tm chuyn khoa ng tin cy v chnh xc ca Bnh vin Trung ng Hu. Tt c cc d kin c ghi chp vo h s hay phiu nghin cu.2.2.2.1. Phng php o huyt p

o theo hng dn Hi Tim mch Vit Nam [9]

Bnh nhn trong trng thi ngh ngi (t nht 5 pht trc o) khng dng cc cht kch thch c nh hng n huyt p (c ph, ht thuc l...).

Bnh nhn t th ngi gh ta, bc l canh tay o huyt ap, tay trn bn sao cho np khuu tay ngang vi mc tim, th lng tay v khng ni chuyn trong khi o. i vi ngi gi v bnh nhn T, khi thm khm ln u th nn o c HA t th ng.

o t nht 2 ln cch nhau t nht 2 pht, con s cui cng l trung bnh cng nu c s khc bit > 5mmHg.Bng qun t ngang mc tim d bnh nhn t th no. Mp di bng qun trn ln khuu 3 cm.o HA c hai tay v ly tr s bn c s o cao hn. Khi cn c th o HA c t th nm hoc ng. HA tm thu tng ng vi pha I ca Korotkoff (xut hin ting p u tin) v HA tm trng l pha V (mt ting p). o huyt p ca bnh nhn trc khi bnh nhn chun b c chp vnh. Kt hp vi ch s HA lc vo vin v tin s THA ca bnh nhn nhn nhn tnh trng THA ca bnh nhn [9].2.2.2.2. Khm lm sng cc i tng nghin cuVic khm v hi bnh s y mi bnh nhn v ch trng- Tm cn nguyn THA th pht loi tr.- Yu t chi phi.

- nh gi cc bin chng (tn thng c quan ch).

- nh gi cc yu t nguy c v tim mch hoc cc ri lon khc c thi iu tr ng mc v t chun ly vo nghin cu [9], [60].

Khai thc bnh s bao gm

Tin s gia nh, ch trng THA, T, thi gian v mc THA.

Tin s lm sng bao gm:

Cc gi tr HA trc y v tn ti bao lu.

S dng cc thuc hay cc cht lm THA nh cam tho, cocaineCc thi quen, li sng nh l ch n m, ht thuc l, ung ru, ch n nhiu mui, tp th dc, trnh gio dc, iu kin sng...

Cc triu chng trong qu kh hoc gn y ca bnh tim mch, tai bin mch no, ri lon m mu...

iu tr thuc h p trc y, mc p ng, tc dng ph v cch thc tun th iu tr.

Cc yu t v mi trng nh hng THA [9], [15], [60].

Thm khm thc th

o HA, bt mach quay, mach canh va mu chn hai bn, nghe M canh, o HA cc t th v o HA t chi. Khm ton trng, chiu cao, cn nng.

Thm khm h tim mch v cc h c quan khc [9], [15], [60].2.2.3. Cc tham s nghin cu khc

2.2.31 Tui v phn nhm tui

Tui c tnh n nm ang tin hnh nghin cu. Phn nhm tui c chia thnh nhm 55 tui, 55< tui 65 v > 65 tui.

2.2.3.2 Gii

2.2.3.3 Ht thuc l

Theo tiu chun ca nghin cu COMMIT (Community Intervention Trial ) [78].Bnh nhn hin l ngi ang c ht thuc l v ht t nht 100 iu tr ln c xem l ngi c ht thuc l.

Ngi bnh cha bao gi ht thuc l hoc c ht nhng ngh ht t nht l 5 nm gn li y c xem la ngi khng ht thuc l.2.2.3.4. Ch s khi c th (BMI)+ o chiu cao v cn nng:

Thc o chiu cao l thc o mu c gn cng vi cn bn c thanh nh mc ngang vung gc vi trc ng ca thc gip xc nh ng chiu cao ca bnh nhn. Dng cn bn hiu TZ 20 c i chiu vi cc cn khc, t v tr cn bng v n nh.

Bnh nhn ng thng t th thoi mi, nhn v pha trc, hai chn song song trn mt cn, hai ngn ci cch nhau 10cm, hai gt chn st mt sau cn, ch mc qun o mng, khng i dp guc v khng i m, khng cm bt k mt vt g. Kt qu tnh bng mt, sai s khng qu 0,5cm.

o trng lng c th bng cn bn TZ 20 c chun ha trc khi s dng. T th o ging nh khi o chiu cao. n v tnh bng kg v sai s khng qu 100g. Cn chnh xc n 0,5kg v o chiu cao chnh xc n 1cm. n v biu th: Cn nng (P) = kg, chiu cao (H) = mT tnh ch s khi c th (BMI) da theo cng thc sau:

)

m

kg

(

H

P

BMI

2

2

=

Bng 2.2. Tiu chun chn on bo ph ca TCYTTG nm 2002 [137]Phn loiBMI ( Kg/ m2)

Gy< 18,5

Bnh thng18,5 - 22,9

Bo ph( ( 23 )C nguy c23 -24,9

Bo 125 - 29,9

Bo 2( 30

Do iu kin dinh dng, chng tc theo vng a l khc nhau v da vo kt qu thc t cc nghin cu v tnh trng bo ph cc nc chu . Da trn ch s BMI v s o vng bng, TCYTTG khuyn co cc nc ny ly tiu chun ban hnh thng 2/2002 lm tiu chun chn on bnh bo ph. Chn on bo ph khi bnh nhn c ch s BMI ( 23 [137].2.2.3.5. Tnh ti

Quan im Hi Tim Mch Hoa K v ngn nga bnh Tim mch.- i tng c xem l c vn ng th lc thng xuyn khi tp luyn u n hng ngy (( 3 ngy/ tun vi thi gian trn 30 pht mi ln tp) nh tp th dc, i b hay chi mt mn th thao no ...

- i tng c xem l t vn ng th lc thng xuyn l i tng khng tp luyn hay tp luyn khng u n (< 3 ngy/ tun) [28].

2.2.3.6. Tiu chun chn on T

Chng ti dng tiu chun chn on T ca T chc Y t Th gii (TCYTTG) nm 1998 v c xc nh li 2002. Chn on xc nh T nu c mt trong ba tiu chun di y v phi c t nht hai ln xt nghim hai thi im khc nhau:

1. Glucose huyt tng (mu tnh mch) bt k trong ngy ( 200 mg/dl ((11,1 mmol/l), km ba triu chng lm sng kinh in gm tiu nhiu, ung nhiu, st cn khng gii thch c.

2. Glucose huyt tng lc i ( 126 mg/dL (( 7mmol/l ) (i c ngha l trong vng 8 gi khng c cung cp ng).

3. Glucose huyt tng hai gi sau ung 75g glucose ( 200 mg/dl (11,1mmol/l) khi lm nghim php dung np glucose bng ng ung [3].

2.2.4. Cc xt nghim c tin hnh Mu mu c gi lm cc ch s sinh ha ti Khoa Sinh ha - Bnh vin Trung ng Hu.

2.2.4.1. Bilan lipid v chn on ri lon Lipid mu- Cholesterol ton phn: nh lng theo phng php so mu enzym, k thut CHOP-PAP (test quang ph men) vi kit Cholesterol FS* (DiaSys).

- Triglycerid: nh lng theo phng php so mu enzym vi kit Triglycerid GPO-PAP.

- HDL-cholesterol: nh lng bng phng php Burstein v Lopes-Virella vi k thut CHOP- PAP. Nng HDL- C bnh thng ca ngi Vit Nam l 0,9 - 2 mmol/l.- LDL- cholesterol: Tnh gin tip theo cng thc FRIEDEWALD

LDL - C (mg/dl) = TC - ( TG/5 + HDL - C ).

( Cng thc ny ch c gi tr trong trng hp TG < 4g/L (< 4,57mmol/l ).

Nng LDL-C bnh thng ngi Vit Nam l < 2,6 mmol/l [12].Ri lon lipid mu c nh gi ch yu bng nh lng bilan lipid mu. Theo tiu chun chn on ca WHO/ISH nm 1999 v khuyn co ATP III - NCEP thng 5/2001, bnh nhn c chn on ri lon lipid mu khi kt qu xt nghim c bt thng mt trong nhng thnh phn lipid:

- Triglycerid tng > 1,7 mmol/l v, hoc

- Cholesterol tng > 5,2 mmol/l v, hoc

- HDL - Cholesterol gim < 1 mmol/l v, hoc

- LDL - Cholesterol tng > 3,4 mmol/l [12], [53].2.2.4.2. Xt nghim v ng mu, cm muLm cc xt nghim c bn

Thi gian mu chy bnh thng 2-5 pht, ko di khi qu 15 pht mu cn chy.

Thi gian ng mu bnh thng 8-15 pht, trn 25 pht l bnh l r rt, t 15 25 pht l nghi ng, cn lm li hoc theo di thm.2.2.4.3. Ure v creatinin muUre c nh lng theo phng php Neman v Jegenhorm vi k thut phn ng enzym urease, gi tr bnh thng 1,7 - 8,3 mmol/l.

Creatinin c nh lng theo phng php Jaff, gi tr bnh thng 62 - 115 (mol/l.

2.2.5. Chp MV chn lc

Chng ti tin hnh chp MV chn lc theo khuyn co ca Hi Tim Mch Hoa K [17], [100].2.2.5.1. Chun b bnh nhn

- Khi c ch nh chp MV, bnh nhn c kim tra li tnh trng lm sng v cc xt nghim cn thit mt ln na.

- Bnh nhn v gia nh c gii thch v th thut, phi c ng ca bnh hoc ngi thn c trch nhim k giy cam oan tin hnh th thut.- Hng dn Bnh nhn nhn n v i v sinh trc khi lm th thut.2.2.5.2. Tin hnh

- Bnh nhn nm nga thoi mi trn bn chp mch, theo di in tim lin tc. Vng M chn lm ng vo (thng l M i phi) c lm sch, st trng (c hai bn) v tri khn v khun c cha l ti ch chc.

- Ngi chp MV mc o ch, ra tay, mc o m v mang gng v khun, ging nh mt cuc phu thut.- Chng ti tin hnh chp MV chn lc theo phng php Judkins, qua ng ng mch i, s dng k thut chc mch qua da ca Seldinger.

V tr chc ng mch i

- Xc nh v tr chc M i ht sc quan trng. Cc bnh nhn bnh thng, im chc mch thng l 1-2cm di cung i, ni M p r.

- Nu chc cao qu, c nguy c gy chy mu vo khoang ngoi phc mc v kh khn khi p cm mu (Hnh 2.2). Ngc li nu chc thp qu c th c bin chng gi phnh mch hoc d ng - tnh mch [10], [17], [24], [27], [100].

Chc ng mch i theo phng php Seldinger

Hnh 2.3 S chc mch theo Seldinger [24].- Sau khi xc nh v tr chc ng mch i, chng ti dng kim nh (s 25- 27 G) gy t ti ch bng 3-5ml Xylocain 2%, sau dng kim ln (18- 22G) ng mch i (c rch 1mm da) ti v tr xc nh trn theo s di (hnh 2.3) .

A: kim chc to thnh mt gc 30- 40( so vi ng mch i v chc vo lng ng mch; B: Mt dy dn ngn c y qua kim vo lng ng mch v t t kim c rt ra qua dy dn trong khi p pha trn ch chc; C: ng t lng c c nng c y vo theo dy dn n st gc ri rt nng v dy dn ra ngoi; D: ng t lng mch c van c nm li trong lng ng mch i [10], [17].Lun ng thng chp vo l vnh .

Thng thng dy dn c lun trong ng thng Judkins tri (hoc phi) s 5F (JL5) ri y qua ng t lng mch c van cm mu (sheath) vo M i. Sau ng thng c y theo dy dn di mn hunh quang ti MC ln. Ti y dy dn c rt ra cn ng thng c ni vi h thng manifold bm ra v theo di p lc ngay (Hnh 2.4).i vi l MV tri dng loi ng thng JL u cong 3; 3,5 hay 4; c 4 - 6F cng dy dn mm t th soi tim u tin chch trc phi (RAO) 300, Khi lun vo l MV tri, y ng thng ti st van t chim, sau ko nh ng thng ra cho n khi c cm gic t vo l MV tri (hnh 2.4 A-D). Trong qu trnh di chuyn ng thng c th bm nh thuc cn quang d tm l MV. Nhng trng hp kh nh MV lc ch, rng ca MV khng ph hp vi ng thng, ta phi thay i loi ng thng JL cc c khc nhau hoc ng thng Amplaz...v phi rt kin nhn khi thc hin th thut.

Hnh 2.5 Biu din p lc bnh thng (A-D), bt thng (B-C) [24]i vi l MV phi dng loi ng thng JR u cong 3; 3,5 hay 4; c 4 - 6F t th soi tim u tin chch trc tri (LAO) 450, y ng thng n mc l MV tri, ng thi ko nh v xoay t t theo chiu kim ng h sao cho cm thy u ng thng nm ng l MV phi (hnh 2.4 E-G). Trong qu trnh di chuyn ng thng c th bm nh thuc cn quang tm l MV. Nhng trng hp kh nh ng mch vnh lc ch, rng ca ng mch vnh khng ph hp vi ng thng th phi thay i loi ng thng JR cc c khc nhau hoc Amplaz... v phi rt kin nhn khi thc hin th thut [10], [17], [24], [27], [100].Trong khi li ng thng cn theo di st p lc u catheter phi biu hin bnh thng (hnh 2.5 A), phng hai tnh hung c th xy ra l ng p lc b tt (damping) (hnh 2.5 C) hoc hin tng tht ha. Hin tng damping c th do u ng thng b t vo thnh MV, cn hin tng tht ha l do y ng thng vo qu su (c 2 l MV) hoc n ch hp kht ca thn chung MV tri lm ng thng bt lun MV (hnh 2.5 B). Khi xy ra hin tng ny cn rt ngay ng thng v gc MC ng p lc s v bnh thng (hnh 2.5 D), c th chp li on phim khng chn lc t xoang Valsalva, gc ng mch ch nh gi s b MV tri (phi), sau thay th bng mt ng thng c nh hn hoc s dng ng thng c l bn. Tuyt i trnh khng c bm thuc chp nu thy hai hin tng trn v c th gy hu qu nghim trng (bc tch thn chung MV tri, rung tht...) [9], [24]. Chp ng mch vnh tri phi chn lc

Tin hnh chp MV, vic bm thuc cn quang rt quan trng. Cn phi bm u tay vi sc y lin tc v mnh m bo cn quang tt h MV. Khi bm cn quang, u bm tim phi hi chc xung bt kh ni ln trn, khng lt vo MV, bm bng tay, mi ln 3-5 ml, thi gian ko di cho n khi xut hin r ht cc nhnh MV, thng 2-3 giy.

T th chp MV tri: chch tri u, chch tri chn, chch phi u, chch phi chn v t th chp ngang. chp MV phi: nghing tri, nghing phi, chch tri u [10], [17], [24], [27], [100].

Kt qu c lu li trn my tng sng, in trn bng video v my tnh, sau c nh gi t nht 2 bc s c kinh nghim v chp MV.

Rt ng thng, p cm mu kt thc chp

Sau khi chp xong, ta rt u ng thng ra khi l MV, va rt ng thng va cho dy dn vo v rt c hai ra ngoi (khng ng t lng chy theo), tip rt ng t lng v p cm mu khong 7 pht. Bng p cm mu v tr chc ng mch, kt thc qu trnh chp. Bnh nhn c theo di sau chp ti phng cp cu tim mch [10].2.2.6. o cng ng mch ch bng vn tc sng mch xm nhp2.2.6.1. L do chn phng php v dng c nghin cu ti

C rt nhiu thng s nh gi CM nh ch s n hi xc nh kh nng n hi ti mt im M, PWV xc nh bn cht thnh mch mt on M, ch s gia tng Trong , PWV c xem l tiu chun vng nh gi CM, phn nh trc tip bn cht thnh M ch khng gin tip nh ch s gia tng. Hai nhm nghin cu u chu, nghin cu Rotterdam [84] v nhm thnh vin an Mch tham gia trong MONICA (Monitoring Trends and Determinants in Cardiovascular Disease) [46], bo co vn tc sng mch ng mch ch (AoPWV), cung cp thng tin d bo vt tri so vi cc yu t nguy c truyn thng bao gm tui tc, gii tnh, huyt p, cholesterol, bnh tiu ng v ht thuc l. Thm vo , khuyn co 2007 Chu u v iu tr THA s dng vn tc sng mch ng mch ch (AoPWV) nh l mt du hiu ca CM vo phn tng nguy c bnh nhn THA trn thc hnh [81]. V vy, chng ti dng vn tc sng mch on MC ln v M i (AoPWV) nghin cu. o vn tc sng mch c th bng phng php xm nhp hay khng xm nhp. Khng xm nhp u im v mt dch t, d ng dng, tuy nhin kh xc nh khong cch gia hai im ng mch kho st v phi o bn ngoi c th. Phng php xm nhp khng p dng rng ri c, tuy nhin chnh xc cao hn v o c khong cch tht gia hai im ng mch nh vo catheter lun vo mch. Mt khc, nghin cu chng ti l nghin cu v l thuyt ban u v trn bnh MV c chp mch nn phng php xm nhp c chn. o vn tc sng mch c tin hnh nh s h tr ca Modun my tnh i km trong h thng chp vnh xa nn DSA ca hng philips ti Trung tm Tim Mch Hu, vi s gip ca phn mm chuyn dng LabSystem Pro c chc nng tnh thi gian truyn sng mch ra ms.2.2.6.2. o vn tc sng mch ng mch ch xm nhp

Vn tc sng mch ng mch ch (AoPWV Aortic Pulse wave velocity) nh gi cng ng mch ch c tin hnh o cho tt c cc i tng nghin cu ngay sau chp vnh. Tin hnh tun t theo sau:

Chun b bnh nhn v th thut

o xm nhp AoPWV ch kt hp trong chp MV nn cng tc

chun b ny cng chnh l chun b bnh nhn cho chp vnh.

Bnh nhn v gia nh c gii thch v th thut, cn phi c s ng ca bnh nhn hay ngi thn c trch nhim k vo giy cam oan chp nhn tin hnh th thut.

Bnh nhn nhn n v i v sinh trc khi tin hnh th thut.

Tin hnh o AoPWV xm nhp

Bc 1: Bnh nhn nm nga thoi mi trn bn chp mch, theo di in tim lin tc. Mt h 3 in cc in tim c dn thm trn 2 vai v di bng bnh nhn, ly tn hiu in tim (DI, DII) ra trn my ghi o lu p lc xm nhp cn cho tnh AoPWV. Khi ng h thng my tnh l Modun i km my chp vnh v phn mm LabSystem PRO ca Modun ny, tin hnh nhp tn, tui, a ch v gii tnh ca bnh nhn. Ni h thng o p lc ca Modun vo h thng o p lc chung trn bnh nhn.

Vng M chn lm ng vo (thng l M i phi) c lm sch, st trng (c hai bn) v tri khn v khun c cha l ti ch chc. Bnh nhn tin hnh c chp MV chn lc theo qui trnh thng thng.

Bc 2: Trc khi kt thc chp MV, c th kt thc chp bung tim bng catheter pigtail 5F, chng ti rt catheter (c dy dn) ra khi bung tim v u catheter ngay v tr st trn van MC (khng chm vo van), dng bm tim 5cc nc mui sinh l bm ra vo catheter (sau rt dy dn) m bo thuc cn quang sch trong lng v khng cn bng kh gip qu trnh o p lc chnh xc. Sau bm ra xong chng ti xoay kha 3 cnh ui catheter v v tr ni thng h thng o p lc xm nhp vi lng catheter tin hnh ghi lu kt qu p lc xm nhp ti gc MC ln t ng vo my khong 10 nhp bp (cn trnh ng tay vo khi b nhiu), sau kha p lc v o chiu di bng thc dy phn catheter ngoi c th khi ghi p lc ti ng mch ch ln, o t tn ng t lng n ui catheter v ghi li kt qu vi chnh xc n 0,5 cm (L1) (hnh 2.6).Bc 3: Sau o chiu di catheter, chng ti tip tc a catheter v M i chung (di soi kim tra), m kha o p lc v tin hnh ghi p lc li ln hai tng t nh trn ti M i. o chiu di catheter ln hai (L2) cng tng t nh trn, nhng cn ch trnh ng t lng chy ra gy kt qu o khng chnh xc. Tc ghi thng l 25 mm/s nh ECG thng thng (hnh 2.6).Bc 4: Sau khi o xong, ta rt ng thng ra ngoi va rt ng thng va cho dy dn vo v rt c hai ra ngoi (khng ng t lng chy theo), tip rt ng t lng v p cm mu khong 7 pht. Bng p cm mu v tr chc ng mch, kt thc qu trnh chp v o. Bnh nhn c theo di sau chp ti phng cp cu tim mch.Phn tch kt qu o AoPWV xm nhpVn tc sng mch on MC ln v ng mch i tnh theo cng thc sau [64],[69]:

AoPWV (m/s) = L / DtL l khong cch truyn sng gia hai im o p lc ti MC ln v M i, o qua trung gian ng thng ng mch pigtail 5F khi chp MV. Khong ny c c bng ly chiu di phn catheter ngoi c th khi ghi p lc ti ng mch i (L2) tr i chiu di phn ngoi c th khi ghi p lc ti gc ng mch ch ln (L1): L = L2 L1. Cc kt qu chiu di L2, L1 c t bc 3, 2 (thc t o chiu di khi ghi p lc ti MC trc). Dt thi gian chm hn ca sng p lc M i so vi sng p lc MC ln, cn c theo chn sng R (hay nh R) ca ECG trn DII ghi ng b vi ghi p lc qua Modun i km h thng chp mch xo nn Philips. Phn tch kt qu thi gian truyn sng mch (bng phn mm LabSystem PRO), chng ti phng i phn ghi p lc xm nhp ln tc 100 mm/s trn my nhn r chn sng p lc cng nh ECG v o thi gian truyn sng t chn sng R ca ECG n chn sng p lc bn t ng nh chc nng phn mm cho ra kt qa ms. o 3 bc sng v in kt qu ra giy, sau chia trung bnh s c kt qu ca thi gian truyn sng mch ti mt v tr o. Ly thi gian truyn sng ti i (T2) tr i thi gian truyn sng ti gc MC (T1) ta c thi gian truyn sng mch t MC ln n M i Dt = T2 T1. Vn tc sng mch tnh theo cng thc trn [64], [69].2.2.7. nh gi bt thng v h MV theo cac tiu chun

2.2.7.1. nh gi on mch(tn thng)hp ng kinh theo ty l %Mc hp MV c tnh: Mc hp (%) = [(Dn- Ds)/ Dn] x 100%.Trong : + Dn l ng knh on mch bnh thng trc tn thng.

+ Ds l ng knh on mch hp nht [24].o ng kinh nh phn mm Philips DICOM Viewer R1.2V1L1-SP012.2.7.2. Phn nng tn thng MV da vo hp Pujadas G

+ Thnh mch bin dng; + hp

0: Khng hp

1: Thnh mch khng ng u, nhng khng hp khu knh

2: Hp khng c ngha khi hp khu knh < 50%

3: Hp c ngha khi hp khu knh t 50 - 75%

4: Hp kht khi hp khu knh t 75 - 95%

5: Hp rt kht khi gn nh ton b khu knh t 95 - 100% km ng thuc cn quang trc ch hp.

6: Tc hon ton [14].

2.2.7.3. Phn loi tn thng MV c v khng co tai vi tri phn nhnh

Tn thng MV c v khng c tai ni phn nhnh theo hng dn ca h im SYNTAX hi can thip tim mch chu u 2005 (hnh 2.7).

Thng tn c xem l tn thng tai vi tri phn nhnh th phi nm 1 trong 7 kiu (A,B,C,D,E,F,G) theo hnh di, vi cc iu kin km theo: tn thng nhnh chnh v nhnh ph phi 50%; nhnh ph phi c ng knh ln hn 1 mm mi c xem xt [117].

2.2.7.4. Phn loi tn thng MV theo Hip Hi Tim Mch Hoa K ACC/AHA (1998) phn chia thnh 3 kiu A,B,C

Kiu A: hp ng tm, ngn < 10mm, khng nm trn on phn nhnh, lng mch trn nhn, khng b canxi ho, t gp tc hon ton, khng hp l, khng c huyt khi.

Kiu B: hp lch tm, di 10-20mm, lng mch khng ng u, g gh, on gn ngon ngho, hp nm on gc phn nhnh > 450; < 900 du hiu canxi ho va, hp l vnh, huyt khi lng mch.Kiu C: hp lan ta > 20mm, on gn rt ngon ngoo, canxi ho, gp gc > 900, tun hon bng h, tn thng nhiu nhnh [2], [10], [17], [24], [100].2.2.7.5. Phn nng ca tn thng MV theo im s gensini + Cho im theo mc gim khu knh

Gim: 25% 1 im. 75% 4 im.

99% 16 im

50%2 im. 90% 8 im.

100% 32 im..

+ V tr tn thng MV tnh theo h s

- Thn chung: h s 5

- MLTT: on gn: h s 2,5; on gia: h s 1,5; vng mm: h s 1, nhnh cho1: h s 1; nhnh cho2: h s 0,5 - ng mch m: on gn: h s 2,5on xa: h s 1

Nhnh b: h s 1; nhnh sau di: h s 1; nhnh sau bn: h s 0,5

- ng mch vnh phi: h s 1

nng tn thng = s im tn thng x h s

im Gensini ca bnh nhn l tng s im Gensini ca cc on hp trn mch [10].

S lng mch mu b tn thng.

S lng cc tn thng c trn c 3 MV.

S lng cc tn thng c hp > 50% [17], [100].

2.2.7.6. Xc nh v tr tn thng trn cc nhnh MV chnh

Cc on I, II v III ca MLTT l tng ng vi cc on gn, gia v on mm theo s cho im ca Gensini. on I, II v III ca MV phi cng tng t l on gn, gia v on xa. on gn v xa ca MM cng nh th [10].

2.2.8. Phng php x l s liuX l s liu theo phng php thng k y hc da theo Excel 2003

v chng trnh SPSS 11.5 (Statistical Package for Social Sciences) [7].

- nh gi: p 0,05: s khc bit khng c ngha thng k

p ( 0,05: s khc bit c ngha thng k

p ( 0,01: s khc bit rt c ngha thng k

i chiu gi tr ca cc ch s gia hai nhm i tng nghin cu s c trnh by di dng trung bnh (X

) v lch chun (SD).

- So snh trung bnh hai tng th v suy on thng k bng cch s dng T - test trn chng trnh SPSS.

- Trong trng hp so snh trung bnh ca nhiu nhm s dng php kim nh F (ANOVA). S khc bit c coi l c ngha thng k khi khong tin cy (CI ) = 95% ( p < 0,05 ).- So snh t l % bng test Chi bnh phng

- Nu tn s nh hn 5 th b sung thm kim nh Yates. Lc ny:

(2 = (

=

-

-

n

i

i

i

i

L

L

Q

1

2

)

5

.

0

- Gi tr khc bit ca hai t l % ca hai nhm khi (2 3,841(p < 0,05 ). tng quan gia cc ch s c biu th bng h s r v kim nh bng gi tr p. Thit lp phng trnh tng quan v v biu tng quan

quan bng chng trnh SPSS 11.5.

kho st s tng quan gia cc thng s, chng ti tnh h s tng quan r vi khong tin cy 95%. Nhn nh tng quan nh sau:+ p 0,05: khng tng quan,

+ p < 0,05: tng quan c ngha thng k v mc cn da vo n.

+ p < 0,01: tng quan rt c ngha thng k.

+ r ( 0,7 : tng quan rt cht ch + r < 0,3 : tng quan yu+ 0,5

r < 0,7 : tng quan cht ch+ r > 0 : tng quan thun

+ 0,3

r < 0,5 : tng quan va

+ r < 0 : tng quan nghch

xc nh tnh c lp ca mt yu t nguy c chng ti dng tng quan hi quy tuyn tnh a bin nh gi. Yu t c xc nh l nguy c c lp khi ch duy nht n c tng quan c p 0,05

Namgii32/6053,3319/4146,3435/6058,3319/4146,34> 0,05

Cao(m)1,550,081,590,081,570,091,580,09> 0,05

Nng(kg)52,509,3055,078,3352,039,1053,498,20> 0,05

BMI

(kg/m2)21,673,0121,712,6721,022,9221,502,59> 0,05

Nhm bnh nghin cu THA B.MV co tui trung binh l 66,07 8,87 tui. Cc nhm i chng cn li ln lt THA kB.MV la 63,17 10,57, kTHA B.MV la 64,88 11,3 v kTHA kB.MV la 62,66 9,02. Tui trung bnh ca cc nhm khng khc nhau p>0,05.

T l nam gii nhom THA B.MV l 53,33 %, cc nhm cn li theo tun t nh trn ln lt l 46,34%, 58,33% v 46,34%. T l nam gii khng khc nhau gia cc nhm (p> 0,05).

Cc ch s nhn trc khc nh chiu cao (m), cn nng (kg) v BMI (kg/m2) ca cc nhm cng tng ng (p>0,05).Tuoi trung binh

90

80

70

60

50

40

30

20

10

0

THA_B.DMVTHA_kB.DMVkTHA_B.DMVkTHA_kB.DMV

Biu 3.1 Tui trung bnh ca cc nhm nghin cu3.1.2. c im v bilan lipid v ng mu

Bng 3.2 Thng s sinh ha mu ca cc nhm bnh v chng

THA kTHAp

B. MV (1)kB. MV (2)B. MV (3)kB. MV (4)

M SDM SDM SDM SD

CT

(mmol/l)4,841,204,881,155,191,294,931,18> 0,05

TG

(mmol/l)2,371,192,661,742,431,602,541,19> 0,05

HDL-C(mmol/l)1,100,311,120,291,090,331,240,41> 0,05

LDL-C(mmol/l)2,651,012,661,162,970,972,531,06> 0,05

G mu(mmol/l)6,301,935,931,396,232,315,692,31> 0,05

Nhom bnh THA B.MV c cholesterol ton phn trung bnh l 4,84 1,2 mmol/l, triglycerid trung bnh l 2,37 1,19 mmol/l, HDL-C trung bnh l 1,10 0,31 mmol/l, LDL-C trung bnh l 2,65 1,01 mmol/l v ng mu trung bnh l 6,30 1,93 mmol/l. Cc thng s ny so vi 3 nhm i chng cn li khng thy khc nhau c ngha (p> 0,05).3.1.3. c im mt s yu t nguy c

Bng 3.3 Tnh trng mt s yu t nguy cTHAkTHAp

B. MV (1)kB. MV(2)B. MV (3)kB. MV (4)

n/60%n/41%n/60%n/41%

RLLP5286,673585,375083,333482,93> 0,05

T813,3337,321016,6749,76> 0,05

Ht thuc2236,671126,832033,33717,07> 0,05

Tnh ti1728,331331,711626,671331,71> 0,05

Bo ph1931,671229,271626,671126,83

Ri lon lipid mu (RLLP), T, tnh trng ht thuc l, tnh ti v bo ph khng khc nhau gia nhm nghin cu THA B.MV vi 3 nhm THA kB.MV, kTHA B.MV v kTHA kB.MV cn li (p> 0,05).3.1.4. c im lm sng ca i tngBng 3.4 Tnh trng huyt p hai nhm THA c va khng co B. MV

THA B. MV (1)n= 60 THA kB. MV (2)n= 41 p

M (mmHg) SDM (mmHg) SD

HATT158,1014,72155,8114,65p1,2 > 0,05

HATTr86,2311,1386,769,60p1,2 > 0,05

HATB114,4013,38113,2211,82p1,2 > 0,05

ALM71,8711,5669,0515,48p1,2 > 0,05

Tnh trng huyt p vi HATT, HATTr, HATB v ALM mch p hai nhm THA c v khng co B.MV l khng khc nhau c ngha thng k (p> 0,05).

Biu 3.2 Tnh trng huyt p nhm THA c v khng c B.MVBng 3.5 Tnh trng phn b theo phn THA

THAp

B. MV n= 60 (1)kB. MV n= 41 (2)

THAn/ 60%n/ 41%

1

3863,332765,85p1,2 > 0,05

2

1525,001024,39p1,2 > 0,05

3

711,6749,76p1,2 > 0,05

Chung60100,0041100,00

P

(cc ) < 0,05, (p2,3>0,05) < 0,05, (p2,3>0,05)

Phn b bnh theo phn THA 1,2,3 nhm THA B.MV ln lt chim 63,33%, 25% v 11,67%. nhm THA kB.MV cng tng t chim t l 65,85%, 24,39% v 9,76%. S phn b bnh theo cac phn THA nay cho thy khng co s khc bit ngha gia hai nhm trn.

0

10

20

30

40

50

60

70

T

l

%

I II III

Phn THA

B.MV

kB.MV

Biu 3.3 Phn THA hai nhm THA

Bng 3.6 Tnh trng huyt p hai nhm kTHA c va khng co B.MV kTHAp

B. MV n= 60 (1)kB. MV n= 41 (2)

M (mmHg) SDM (mmHg) SD

HATT121,5812,24122,8810,29p1,2 > 0,05

HATTr70,759,5572,938,35p1,2 > 0,05

HATB88,4211,5289,329,72p1,2 > 0,05

ALM51,0010,7549,958,30p1,2 > 0,05

Tnh trng HA hai nhm kTHA c v khng c B.MV vi HATT ln lt l 121,58 12,24 mmHg v 122,88 10,29 mmHg, khng khc nhau c ngha. Tng t HATTr, HA trung bnh, p lc mch hay HA mch p cua hai nhom kTHA c v khng c B.MV trn cng khng khc nhau co ngha (p> 0,05).3.2. C IM HNH NH V MC TN THNG MCH VNH3.2.1. Phn b h ti mu MV u th (sinh l)

Trn tim c hai MV phi, tri ti mu nui dng. Trong phn ln trng hp s ti mu ny l khng cn bng v thng l MV phi ti mu u th. Bn no u th th MLTS xut pht t nhnh MV bn . Bng 3.7 Phn b h ti mu MV u th

Ti mu u th

/Nhm bnhPhi (1)Tri (2)p

n/ 60%n/ 60%

THA B. MV 4880,001220,00p1,2 < 0,0001

kTHA- B. MV 4473,331626,67p1,2 < 0,0001

P> 0,05> 0,05

Ca hai nhom bnh cho thy ti mau MV u th phai chim a s. c im ti mu u th phi trn nhm THA B.MV chim 80% v kTHA B.MV la 73,33%, cho thy khc bit khng co ngha (p>0,05).

Ngc lai ti mu u th tri chim ty l thp va cung cho thy khng co s khc bit c ngha thng k gia hai nhom.

80

20

73.33

26.67

0

20

40

60

80

100

THA-B.

MVkTHA-B.

MV

T l %

u th phi

u th trai

Biu 3.4 T l u th ti mu MV3.2.2. Thng tn cc nhnh chnh MV chnh

Nhm 60 bnh nhn THA nguyn pht v kTHA c B.MV trong nghin cu chng ti c t l tn thng cc nhnh chnh MV nh sauBng 3.8 T l tn thng cc nhnh MV chnhMLTT

(1)M M

(2)MV phi (3)Thn chung (4)p

n/60%n/60%n/60%n/60%

THA B.MVNam2338,331220,002338,3323,33 0,05)

N2135,001525,001525,0011,67 0,05)

Tng4473,332745,003863,3335,00 0,05)

P (nam-n)> 0,05> 0,05> 0,05> 0,05

kTHA B.MV Nam

3050,00915,001728,3323,33< 0,05; (p2,3; > 0,05)

N1830,001321,67915,0011,67 < 0,05; (p1,2; p1,3;p2,3; > 0,05)

Tng4880,002236,672643,3335,00< 0,05; (p2,3; > 0,05)

P (nam-n)< 0,05> 0,05> 0,05> 0,05

P

(THA-kTHA)> 0,05> 0,05< 0,05> 0,05

Nhom THA B.MV thng tn MLTT, MV phi gn tng ng v ln hn M m. Nam ty l tn thng MLTT v MVp khng khc nhau (p> 0,05) nhng ln hn M m (p< 0,05). n xu th tri trn MLTT so vi MVp v M m, s tri ca MVp so vi m mt i (P> 0,05). Trn mi nhnh MV chnh tn thng khng c s khc bit gia nam v n.Trn nhom kTHA B.MV tn thng MLTT cao nht, tip n l MVp v cui l MM. nam co tn thng MLTT vt hai mch cn li (p< 0,05). n cha thy s vt tri (p> 0,05). MLTT nam cao hn n (p< 0,05), tn thng hai MV cn li cha khc bit v gii (p>0,05).Tn thng thn chung thp chi chim 5% trng hp c hai nhm. Tn thng MVp nhom THA B.MV cao hn nhom kTHA B.MV (63,33% so vi 43,33% p< 0,05). Nam THA co tn thng MLTT v MV phi ngang nhau v vt tri hn M m, cn nam kTHA vt tri r rng trong MLTT so vi hai mch cn li. N ca hai nhm co u th tn thng MLTT nhng cha ngha p>0,05.

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MLTTMMMV phaiThn chung

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Biu 3.5 T l mc bnh ca cc nhnh MV chnh Bng 3.9 OR tn thng MV gia nhm THA so vi kTHA

OR95% CIp

MLTT0,68750,293 1,6133> 0,05

MM1,41320,6803 2,9356> 0,05

MVp2,25871,0859 4,6985< 0,05

C nguy c tn thng MLTT gim v MM tng khi so sanh gia nhm THA vi nhom kTHA nhng cha c ngha (p> 0,05). Ngc li nguy c tng tn thng MV phi vi ty sut chnh OR = 2,2587 (95% CI: 1,08594,6985), p 0,05)

N915,001423,3358,3311,67< 0,05

(p1,2; p1,3; p3,4 > 0,05)

Tng1931,673050,001118,3335,00< 0,05 ;

(p1,3> 0,05)

P (nam-n)> 0,05> 0,05> 0,05> 0,05

kTHA - B.MV Nam1931,671220,0046,6723,33< 0,05 (p1,2; p2,3; p3,4> 0,05)

N1626,6635,00610,0011,67< 0,05(p2,3; p2,4; p3,4> 0,05)

Tng3558,331525,001016,6735,00< 0,05(p2,3; p2,4; p3,4> 0,05)

P (nam-n)> 0,05< 0,05> 0,05> 0,05

P

(THA-kTHA)< 0,05< 0,05> 0,05> 0,05

Nhom THA B.MV tn thng 2 nhnh chim t l cao nht 50,00% (p0,05). Trn ca hai gii xu hng u th tn thng 2 nhnh, 1 nhnh ri n 3 nhnh song cha ngha (p>0,05). Mi cp s nhnh tn thng theo gii cha thy khc bit.

nhom kTHA B.MV tn thng 1 nhnh co t l cao nht (p 0,05p1,3; p2,3 < 0,05

p> 0,05> 0,05> 0,05

Phn b tn thng trn ng mch lin tht trc chng ti ch xt trn nhng c th c tn thng MLTT vi 43 bnh nhm c THA v 48 bnh nhm kTHA. Tn thng on II c t l cao nht c hai nhm, 60,47% nhm c THA v 60,42% nhm kTHA.

Bng 3.13 Phn b tn thng trn M mon gn (1)on xa (2)p

n%n%

THA - B,MV

(N = 27 bnh)933,331866,67P1,2 < 0,05

kTHA - B,MV

(N = 22 bnh)1254,551463,64P1,2 > 0,05

P> 0,05> 0,05

Phn b tn thng trn M m, chng ti cng ch xt trn nhng c th c tn thng M m vi 27 bnh nhm THA v 22 bnh kTHA. Tn thng on gn nhm kTHA l 54,55% khng khc bit vi oan xa 63,64% (p> 0,05). Tn thng MM nhm THA c s khc bit r gia on gn 33,33 % so vi on xa 66,67% (p< 0,05).

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Biu 3.7 Phn b tn thng trn M m

Bng 3.14 Phn b tn thng trn MV phion I (1)on II (2)on III (3)p

n%n%n%

THA-B.MV

(N = 38 bnh)1128,952565,79615,79p1,3 > 0,05p1,2; p2,3 < 0,05

kTHA-B.MV

(N = 26 bnh)415,392180,77726,92p1,3 > 0,05p1,2 ; p2,3 < 0,001

p> 0,05> 0,05> 0,05

Phn b tn thng trn MV phi chng ti cng ch xt trn nhng c th c tn thng MV phi vi 38 bnh nhm c THA v 26 bnh nhm kTHA. Tn thng on II c t l cao nht c hai nhm, 65,79% nhm THA v 80,77% nhm kTHA. Tn thng on I c xu hng nhiu hn on III nhm THA nhng cha c ngha vi 28,95% so vi 15,79% (p> 0,05). nhm kTHA xu hng ngc li on I 15,39%, on III 26,92% nhng cung cha c ngha thng k p> 0,05.3.2.4Phn tn thng theo kiu hp ca MV3.2.4.1. Tn thng MV c v khng c tai vi tri phn nhnh

Bng 3.15 Tn thng ni phn nhnh v khng phn nhnh ca h MV

MLTT

(1)M m

(2)MV phi

(3)Tng

(4)p

n%n%n%n%

THA-B.MVPhn nhnh4375,442681,253673,4710576,09 > 0,05

k Phn nhnh1424,56618,751326,533323,91 > 0,05

Tng57100,032100,049100,0138100,0

P (phn/khng)< 0,0001< 0,0001< 0,0001< 0,0001

kTHA-B.MVPhn nhnh3552,242369,71232,437051,1> 0,05;

(p2,3 < 0,05)

k Phn nhnh3247,761030,32567,576748,9> 0,05;

(p2,3 < 0,05)

Tng67100,033100,037100,0137100,0

P (phn/khng)> 0,05< 0,01< 0,01> 0,05

P (phn nhnh

THA-kTHA)< 0,05> 0,05< 0,001< 0,0001

Tn thng tai ni c v khng co phn nhnh cua MV tnh trn tt c cc tn thng ca cy MV k c nhnh chnh v ph. V ch ly cc tn thng hp ng knh 50 %. Tng tn thng nhm THA l 138 (khng k trn thn chung) v nhm kTHA l 137 tn thng.

THA B.MV co tn thng tai vi tri phn nhnh chim t l cao 76,09% so vi tai vi tri khng phn nhnh 23,91% rt c ngha (p < 0,0001). Trn mi nhanh chinh MV cng c u th nh vy. Ngc li kTHA B.MV khng thy khc nhau v tn thng ni c v khng c phn nhnh, t l l 51,1% v 48,9% theo th t cho mi loi (p> 0,05). Cac nhanh MV kTHA cung c u th ni phn nhnh nhng ring MV phi c u th ngc li vi tn thng vi tri khng phn nhnh t l cao hn.

So sanh hai nhm th tn thng ni phn nhnh THA cao hn so vi kTHA theo t l 76,09% va 51,1%, khac rt c ngha p < 0,0001. Tn thng ni khng phn nhnh u th hn nhm kTHA so vi THA theo t l 48,9% so vi 23,91% vi mc ngha thng k rt cao p< 0,0001.

Tn thng tai vi tri phn nhnh u th trong nhm THA. Cn trong nhm kTHA cha thy u th tn thng tai vi tri phn nhnh.

EMBED MSGraph.Chart.8 \s 76,09

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Biu 3.8 Phn b tn thng c v khng c phn nhnh.

Bng 3.16 OR nguy c tn thng ni phn nhnh gia c v khng THAKiu tn thngOR95% CIp

Phn nhnh3,04551,8197 5,0969< 0,0001

Khng phn nhnh0,3284 0,1962 0,5495< 0,0001

Tn thng ni phn nhnh nhm THA B.MV cao hn so vi nhm kTHA B.MV vi OR= 3,0455 (95%CI: 1,81795,0969) p < 0,0001.

Tn thng ni khng phn nhnh thp hn nhm B.MV THA so vi kTHA vi OR= 0,3284 (95%CI: 0,1962 0,5495) p < 0,0001.3.2.4.2. Tn thng MV theo kiu A, B, C

Bng 3.17 Phn tn thng theo kiu hp A, B, C

MLTT (1)M m (2)MV phi (3)Tng (4)p

n%n%n%n%

THA-B.MVA1322,811134,38714,293122,46> 0,05

B3256,141443,752551,027151,45> 0,05

C1221,05721,871734,693626,09> 0,05

Tng57100,032100,049100,0138100,0> 0,05

PPB-A,C< 0,001>0,05< 0,05PB-A,C< 0,001

kTHA-B.MVA1522,38721,21616,212820,43> 0,05

B2638,811648,491848,656043,80> 0,05

C2638,811030,301335,144935,77> 0,05

Tng67100,033100,037100,0137100,0> 0,05

P> 0,05PB-A < 0,05PA-B,C< 0,05PB-A < 0,001

P

(B THA-kTHA)> 0,05> 0,05> 0,05> 0,05

THA kiu B t l cao nht so hai loi cn li p< 0,0001, cn A v C tng ng. T l A,B,C ln lt l 22,46%, 51,45%, 26,09 %. MLTT B vt tri r, MVp B cng vt tri nhng M m vt tri B cha r hn.

kTHA kiu B 43,80% cao tri hn A 20,43% (p0,05). T l A,B,C l 20,43%, 43,80%, 35,77%. MLTT B, C tng ng v ln hn A nhng cha ngha. MM v MV phi B hn A nhng khng tri hn hn C.

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Biu 3.9 Phn b tn thng kiu A, B, C3.2.5. Mc tn thng MV theo mc hp ng knh Bng 3.18 Mc tn thng theo mc hp c ngha tr ln

MC HP/ Nhm bnhHp va

50-< 75% (1)Hp kht

75- < 95% (2)Rt kht95- 0,05> 0,05> 0,05> 0,05

MMTHA- B.MV (N= 27)1555,56829,63311,1113,70> 0,05

kTHA B.MV(N= 22)522,731045,46522,7329,09< 0,001

p> 0,05> 0,05> 0,05> 0,05

MV phiTHA- B.MV (N = 38)1744,741128,9525,26821,05> 0,05

kTHA B.MV(N= 26)1038,46415,39415,39830,77> 0,05

p> 0,05> 0,05> 0,05> 0,05

ChungTHA- B.MV (N = 109)4541,283935,781311,931211,01< 0,05

kTHA B.MV(N= 96)3233,333435,421717,711313,54< 0,001

p> 0,05> 0,05> 0,05> 0,05

Mc hep nay c tinh cho cac nhanh MV chinh bi tn thng ng vi tn thng nng nht co trn nhanh chinh MV o lam ai din, khng phai la cac tn thng ri cung co mt trn nhanh o.Trn MLTT, so snh cc cp hp gia nhm THA va kTHA khng thy c s khc bit (p> 0,05). ca hai nhm hp kht tr ln ( 75%) chim t l kh cao, nhm THA la 70,45% va nhm kTHA la 64,59%.

Trn M m: cc cp hp so snh gia hai nhm khng thy c s khc bit (p> 0,05). Trong nhm THA hp kht tr ln chim 44,44% v hp va 55.56% khc bit cha c ngha. Nhm kTHA c t l hp kht tr ln chim 77,27% cao hn c ngha so vi hp va 22,73% p< 0,001.

Con MV phi: cc cp hp khng khc nhau gia hai nhm. Hp va v kht tr ln chim t l gn tng ng nhau c hai nhm.

Trong ca hai nhom nghin cu, s bnh nhn co MV hp kht va trn mc hep khit ( 75%) nhom THA la 58,72% va nhom kTHA la 66,67 %.3.2.6. Mc tn thng MV theo im GensiniBng 3.19 nng tn thng theo im Gensini

im Gensini

/ GiiTHA- B.MV (1)kTHA- B.MV (2)p

nM SDnM SD

Nam3223,05 16,773525,16 19,35p1,2 > 0,05

N2822,41 21,772528,46 33,29p1,2 > 0,05

Chung6022,75 19,106026,53 25,87p1,2 > 0,05

p> 0,05> 0,05

im tn thng ng mach vanh Gensini ca hai nhom bi bnh MV co THA va khng THA u khng co s khac bit co y nghia thng k gia nam va n, gia THA va khng THA.Diem Gensini

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Biu 3.10 Phn b tn thng theo im Gensini3.3. CNG NG MCH THEO VN TC SNG MCH MC V MI LIN QUAN CA N VI MC TN THNG MV

3.3.1. nh gi cng ng mch bng vn tc sng mch MC3.3.1.1. Vn tc sng mch MC theo tui, gii

Bng 3.20 Cng ng mch qua vn tc sng mch MC THA

AoPWV (m/s)Nhm bnh/

Gii - Tui(nm)THA B.MVTHA kB.MVp

nMSDnMSD

Nam 55 (1)810,101,8047,611,65< 0,05

>55/ 65 (2)611,371,3949,822,07> 0,05

>65 (3)1812,962,401110,292,48< 0,01

Tng3211,942,39199,622,40< 0,01

P (nhm tui)< 0,01< 0,01 ( p2,3 >0,05)

N 55 (1)28,980,1888,700,94> 0,05

>55/ 65 (2)710,130,8059,271,76> 0,05

>65 (3)1911,802,48910,341,51> 0,05

Tng2811,182,27229,501,52< 0,01

p (nhm tui)< 0,05< 0,05

Chung 55 (1)109,871,65128,331,26< 0,05

>55 / 65(2)1310,701,2499,511,80> 0,05

>65 (3)3712,362,482010,312,05< 0,01

Tng6011,592,35419,561,95< 0,001

P (nhm tui)< 0,01< 0,05 (p2,3 >0,05)

P (nam- n)= 0,077> 0,05

AoPWV nhm THA B.MV tng dn y nghia theo nhm tui tng, 55 tui l 9,87 1,65 m/s, 55< - 65 tui l 10,7 1,24 m/s v > 65 tui l 12,36 2,48 m/s (p 0,05

>55/ 65 (2)129,720,9228,630,62> 0,05

>65 (3)1210,622,5289,272,03> 0,05

Tng359,552,37198,562,40> 0,05

P (nhm tui)< 0,05< 0,05 (p2,3 > 0,05)

N 55 (1)27,750,3186,791,12> 0,05

>55/ 65 (2)68,030,8467,850,56> 0,05

>65 (3)179,902,3988,321,10> 0,05

Tng259,282,19227,631,17< 0,01

P (nhm tui)< 0,05< 0,05

Chung 55 (1)138,122,56177,031,76> 0,05

>55 / 65(2)189,161,2088,050,64< 0,05

>65 (3)2910,202,42168,801,65< 0,05

Tng609,442,28418,071,88< 0,01

P (nhm tui)< 0,05< 0,05

P (nam- n)> 0,05< 0,05

AoPWV kTHA B.MV tng dn theo nhm tui 55 l 8,12 2,56 m/s, >55/65 tui l 9,16 1,20m/s v >65 tui l 10,20 2,42 m/s vi khc c ngha (p 55 / 65 (2)1310,701,24189,161,20

> 65 (3)3712,362,482910,202,420,05 (0,2560)

ALM (trung tm mmHg)0,0033-0,0277>0,05 (0,5849)

HATB (ngoi bin mmHg)-0,0068-0,112>0,05 (0,5164)

ALM (ngoi bin mmHg)0,00410,0041>0,05 (0,7301)

AoPWV (m/s)0,15270,3760,05 (0,4284)

Gii (nam 1, n 2)4,34230,064>0,05 (0,6179)

BMI (kg/m2)-0,4540-0,128>0,05 (0,71530

Cholesterol (mmol/l)0,5014-0,058>0,05 (0,8452)

ng mu (mmol/)-0,8961-0,041>0,05 (0,6439)

T (c 1, khng 0)15,66010,101>0,05 (0,17410

Ht thuc l (c 1, khng 0)-0,6778-0,204>0,05 (0,9390)

Tnh ti ( c 1, khng 0)0,96010,017>0,05 (0,9013)

HATB (trung tm mmHg)-0,2278-0,378>0,05 (0,6547)

ALM (trung tm mmHg)-0,3229-0,113>0,05 (0,3877)

HATB (ngoi bin mmHg)-0,3528-0,264>0,05 (0,4886)

ALM (ngoi bin mmHg)0,1810-0,127>0,05 (0,6677)

AoPWV (m/s)5,20570,4530,05 (0,5646)

Gii (nam 1, n 2)0,07890,0186>0,05 (0,7461)

BMI (kg/m2)0,0036-0,0646>0,05 (0,9185)

Cholesterol (mmol/l)0,07620,0852>0,05 (0,2928)

ng mu (mmol/)0,0051-0,0906>0,05 (0,9247)

Ht thuc l (c 1, khng 0)0,1078-0,124>0,05 (0,6644)

T (c 1, khng 0)0,37590,0098>0,05 (0,2431)

Tnh ti ( c 1, khng 0)0,12570,0827>0,05 (0,5631)

HATB (trung tm mmHg)0,0076-0,211>0,05 (0,5966)

ALM (trung tm mmHg)-0,0100-0,0469>0,05 (0,3403)

HATB (ngoi bin mmHg)-0,0257-0,134>0,05 (0,0761)

ALM (ngoi bin mmHg)0,02590,0206 0,05).So snh cc nghin cu khc nh nghin cu ca Ng Vn Hng v cs (2009) ti Hu trn bnh nhn B.MV c hi chng chuyn ha vi t l THA ln n 92,3% v tui trung bnh l 66,74 ( 9,21 tui gn nh chng ti. T l nam n cng khng khc my (38,46% nam so vi n 61,54%, p >0,05) [5]. Tuy nhin, nghin cu bnh MV khc nh nghin cu ca Phm Thu Linh v cng s (2005) Vin tim Tp.HCM, trn bnh nhn hi chng vnh cp cho thy t l nam nhiu hn n c ngha (60,59% so vi 39,46%, p 0,05. 4.1.3. c im v cc yu t nguy c

4.1.3.1. Ri lon lipid mu

Ri lon lipid mu l yu t nguy c chim t l cao nht trong nghin cu chng ti 86,67% THA vi B.MV. Nghin cu khc nh nghin cu ca Phm Thu Linh (HCVC) t l ri lon lipid mu chim t l 71,43% [8], ca Phm Hon Tin (NMCT) chim 58,3% [14], ca A Rosengren v cs ri lon m mu chim 47% [108], ca Jankowski P. v cs (2007) ti Ba Lan l 88,1% [54]. Theo Sukhija R v cs t l ri lon lipid ngi c x va ng mch ngoi vi chim 73% [124]. Gn y, da trn nhiu nghin cu iu tra dch t, NCEP khuyn co gim m mu m c bit l LDL-C lm gim t l mc bnh MV ng k, c bit bnh nhn c nguy c cao [16].

Bnh nhn THA c B.MV nghin cu ca chng ti t l ri lon m mu l cao so vi cc th bnh khc nh nu trong cc nghin cu trn.4.1.3.2. Ht thuc l

Ht thuc l trong nghin cu ca chng ti l 36,67 % nhm THA B.MV. So vi cc nghin cu khc nh Phm Thu Linh t l ht thuc chim 42,86%, ca Nguyn Hng sn l 32,6% [13]. Theo H Anh Bnh t l ht thuc l trong suy vnh chim 30,43%[2]. Theo nghin cu ca A.Rosengren t l y cn thp hn 30 % trong HCVC chung. theo nghin cu Jankowski P. v cs (2007) ti Ba Lan l 11% THA vi B.MV [67]. iu ny khng nh tnh trng ht thuc Hu c t l kh cao so vi u Chu. Trn bnh nhn suy vnh ca nghin cu H Anh Bnh, t l ht thuc l l 30,43% th thy nhm THA c bnh MV ca chng ti c t l kh cao. iu ny ni ln tc hi ca thuc l trong vic thc y a n bnh mch vnh nht l khi c THA km theo (gim NO co mch vnh). Sukhija R v cs cho thy ngi bnh x va c t l ht thuc l cn cao hn ln ti 85% [124]. Ngoi ra, theo Mazzone A v cs (2001) ht thuc l v THA nh hng gim ng k n phng thch NO, tng nng cc phn t bm dnh gian bo ha tan sICAM (soluble Intracellular cell Adhesion Molecule), sVCAM (soluble vascular cell Adhesion Molecule) t l vi nng Cotinine (sn phm chuyn ha bn ca Nicotine), thc y qu trnh suy chc nng ni m v x va [86].

4.1.3.3. i tho ng

T l T nghin cu chng ti trn THA vi B.MV l 13,33%. T l ny tng ng vi ba nhm i chng cn li v ch chim t l rt thp.4.1.3.4. Bo ph

Nghin cu ca chng ti bnh nhn THA B.MV t l bo ph chim 31,67%. Theo Phm Thu Linh bnh MV cp t l bo ph chim 33,33%, ca H Anh Bnh chim 10,14%, theo nghin cu Jankowski P. v cs (2007) ti Ba Lan BMI ca bnh nhn THA vi B.MV l 27,9 ( 4,6) [54]. Nh vy bo ph Vit Nam thp hn u Chu. Tuy nhin so vi nhm suy vnh, TN n nh th B.MV c THA c t l bo ph cao hn.

4.1.3.5. Tnh ti

Nhm nghin cu ca chng ti c t l tnh ti t vn ng th lc chim 28,33% v tng ng vi 3 nhm i chng. Theo Hamer M (2006) tp th dc nh hng n HA v c bit tt cho bnh nhn c tin s gia nh THA [45]. NMCT hay xy ra ngi t vn ng km a yu t nguy c theo Satyendra Giri v cs (1999) [42]. Vn ng gim trng lng v tng tc dng ca thuc chng HA theo Xu KT v Ragain RM (2005) [140].

4.1.4. c im lm sng ca i tng

Nhm THA B.MV ca chng ti vi tnh trng HATT 158,1 14.72 mmHg, HATTr l 86,23 11,13 mmHg khng khc nhau c ngha vi nhm THA kB.MV vi HATT 155,81 14,65 mmHg v HATTr 86,76 9,60 mmHg (p>0,05). Ngoi ra HATB v ALM cng tng ng hai nhm THA nghin cu. Xt v phn THA th hai nhm nghin cu ny cng tng ng vi THA 1,2,3 c t l 63,33%, 25,00%, 11,67% nhm THA B.MV v 65,85%, 24,39%, 9, 76% nhm THA kB.MV (p> 0,05).

Tnh trng HA ca hai nhm kTHA c v khng c B.MV theo nh bng 3.6 th cng khng khc nhau p> 0,05.

Tm li, tnh trng HA trong tng cp THA v kTHA trong bn nhm nghin cu ca chng ti l kh tng ng.4.2. C IM HNH NH V MC TN THNG MV4.2.1. c im ti mu

Nghin cu chng ti thy rng u th MV phi ti mu nhm THA v kTHA l 80% v 73,33%, khc khng c ngha thng k (p0,05). C hai MV ny tn thng u cao hn tn thng M m (t l 45%). Xu hng vt tri MLTT, MV phi so vi M m c ghi nhn y. Xt su hn vo gii nam, u th tn thng MLTT, MV phi l tng ng v vt tri hn so vi M m cn li. Nh th trong nam gii c s gia tng r tn thng MV phi ln tng ng vi MLTT. n, s vt tri tn thng MLTT so vi c hai MV phi v m. S vt tri ca MV phi so vi m mt i ch cn tng ng nhau. Trn mi nhnh MV chnh khng c s khc bit gia nam v n. Xt trn nhm kTHA B.MV t l tn thng l cao nht 80% trn MLTT tip n l t l mc bnh MV phi 43,33% v cui cng l MM chim t l 36,67%. S u th r rng trn MLTT c ngha hn k c tn thng MV phi, khng nh tnh trng nhm bnh trn. Vt tri r MLTT ri n MV phi, cui cng M m. u th tn thng MV phi khng ni r nh nhm THA. Nam tn MLTT vt tri hn hai mch vnh chnh cn li. N s vt tri l khng r rng, d xu th vn nh vy. Trn tng nhnh MV chnh, MLTT nam cao hn n, cn cc nhnh MV cn li khng khc bit tn thng gia nam v n.

Thn chung tn thng rt thp chim 5% trng hp c hai nhm. So snh hai nhm ta thy ni tri ln c s khc bit gia tn thng MV phi THA so vi kTHA c