Left-Right ShuntNatural history & Principles of Management

Most common congenital heart defect in children

Incidence is 8 per 1000 live births

Echo studies- 5 to 50 per 1,000 newborns

Ooshima A et al. Cardiology 1995;86:402-406.

No sex preference , except in subarterial defect

ASIAN WESTERN

Doubly commitedsubarterial

Multiple ventricular septal defects are rare

Doubly-commitedsubarterial defect requiring repair is 30%

Muscular defects

10% in the west

5% in western

Ferreira Martins JD et al.Cardiol Young 2000; 10: 464–73.

Pathologic anatomy of IVS

Soto et al classification of VSD Perimembranous (membranous/ infracristal )-70-80%

Muscular- 5-20% Central- mid muscular

Apical

Marginal- along RV septal junction

Swiss cheese septum – multiple defects

Inlet/ AV canal type-5-8%

Supracrital (Conal/ infundibular/subpulmonary/doubly committed subarterial)- 5-7%

Benigno soto et al. Br HeartJ 1980; 43: 332-343

Restrictive- less than one third of aortic root LVSP > > RVSP

Pulm /Aortic systolic pressure ratio < 0.3

Qp / Qs<1.4:1

Moderately restrictive RVSP high, but less than LVSP

Qp/Qs 1.4:2.2

Non restrictive - The size of aortic orifice RVSP , LVSP, PA Aortic systolic pressures are equal

Qp/Qs >2.2

Flow determined by PVR

Anterior more common than posterior

Usually involves the infundibular septum

Occurs as if there is a door that moves round on a hinge

The outcome and natural history influenced by

Position & Size

Number of defects

Anatomic structures in the vicinity of the defect

Association of other malformation

Age at which the defect is recognized

Sex of the patient

Cardiac failure

Spontaneous diminution in size or closure

Right or Left ventricular outflow tract obstruction

Aortic regurgitation

Pulmonary vascular obstructive disease

Infective endocarditis

Rare in small VSD as size limits the L-R shunt

In large VSD the relative resistances of the systemic and pulmonary circulations regulate flow

Shunt occurs mainly in systole

Shunt directly to PA

Enlargement of LA, LV,PA

After birth decline in PVR to adult level by 7to 10 days

In large VSDs, the rate of this process is delayed

Small VSD the shunt is small & remain asymptomatic

Moderate sized VSD symptoms by 1to 6 months

Rarely, adults present with new exercise intolerance

.)

Rudolph AM, et al.Pediatrics 1965;36:763-772.

Large VSD congestive heart failure in first few weeks

Risk for recurrent pulmonary infection high

If survives without therapy - pulmonary vascular disease develop in the first few years of life

Symptoms “get better” as Qp/Qs returns to 1:1

Intervention at this time - a shorter life expectancy than if the defect were left open

Fuster V, et al.Cardiovasc Clin. 1980;10:161–197.

Occurs in both perimembranous and muscular

Closure is documented in the fetus & in the adult

VSD diagnosed in the fetus - 46% closed in utero & 23.1% in the first year, while 30.8% remained patent

In this study 15.8% of defects < 3 mm remained patent in comparison to 71.4% > 3mm at 1yr

Nir A et al.Pediatr Cardiol 1990; 11: 208–10.

More frequent in <10 yrs of age

Isolated VSD ( 124 pts) - 34% at 1 yr & 67% at 5 yr

Female predominance

Decreases substantially after 1 year of age

Mehta AV et al. Tenn Med 2000; 93: 136–8.

Farina MA et al . J Pediatr 1978; 93: 1065–6.

Moe DG et al. Am J Cardiol 1987; 60: 674–8.

Rare in malaligned VSD

In outlet VSD closure only in 4%

All of the defects closed were initially < 4 mm

Tomita H et al. Jpn Circ J 2001; 65: 364–6

Different for perimembranous and muscular

Perimembranous Reduplication of tricuspid valve tissue

Progressive adherence of the septal leaflet of the tricuspid valve about the margins of the VSD

Aneurysmal transformation of the membranous septum (appearance on angiography)

Early systolic click & late crescendo systolic murmur

Anderson RH et al . Am J Cardiol 1983; 52: 341–5.

Freedom et al. Circulation 1974; 49: 375–84.

Muscular- direct apposition of muscular borders

Large subarterial defect don’t close

A. Closure of a perimembranous defect by adhesion of the tricuspid leaflets to the defect margin.

B. Closure of a small muscular defect by a fibrous tissue plug.

C. Closure of a muscular defect by hypertrophied muscle bundles in the right ventricle

D. Closure of a defect in subaortic location by adhesion of the prolapsed aortic valve cusp

Incidence 3% to 7%.

Mechanism:- Hypertrophy of malaligned infundibular septum

Hypertrophy of right ventricular muscle bundles

Prolapsing aortic valve leaflet

High incidence inRight sided aortic arch

Horizontal RVOT

Nadas AS et al . Circulation 1977; 56(No.2, Suppl. I): 1–87.

Corone P et al. Circulation 1977; 55: 908–15.

Pongiglione G et al . Am J Cardiol 1982; 50: 776–80.

Varghese PJ et al . Br Heart J 1970; 32: 537–46.

Tyrrell MJ et al. Circulation 1970; 41 & 42(Suppl. III): 113.

VSD with direct contact with the aortic valve are most prone to develop AVP

All the perimembranous defects

All doubly committed juxtaarterial defects

Most of muscular outlet defects

Characteristic deformity of aortic cusp-nadir of the cusp is elongated

RCC (60-70%) , NCC (10-15%) , both in 10-20%

Non-coronary cusp prolapse in perimembranous type

Left coronary cusp prolapse extremely rare

AR may be due to incompetent bicuspid aortic valve

Rarely prolapsed valve cusp may perforate

Pathogenesis

Anatomic factors for normal competence Leaflet support by diastolic apposition

Infundibular support from below

Intrinsic structural abnormalityProgressive discontinuity between aortic valve annulus & media

PathogenesisHemodynamic factor

‘’Venturi effect’’

VSD is restrictive, Qp/Qs<2 , absence of PAHKomai H et al.Ann Thorac Surg 64:1146-1149, 1997

Unknown exact prevalence (2% to 7%)

Rare before 2 years

More severe - additional volume load

Aneurysm of sinuses of Valsalva may develop

Nadas AS et al . Circulation 1977; 56(No.2, Suppl. I): 1–87.

362 Patients. 37 (10.2%) had AR

Mean age 13.4 years ( 2-45),male to female ratio 5:1

31 (84%) had infracristal & 6 (16%) supracristal VSD

Infracristal VSD-RCC prolapse in 14 (48%) &NCC in 12 (41%) and both RCC and NCC in 3 (11%)

Supracristal VSD - RCC prolapse in 5 (83%),NCC in 1

Two patients the AR was due to bicuspid aortic valve

PA pressure normal in 26(70.2%), L-R shunt 1.5:1 or less in 23 (62%)

No relationship- severity of AR & location of VSD

Somanath HS et al. Indian Heart J. 1990 Mar-Apr;42(2):113-6.

Indicated for both perimembranous and subarterial VSDs when more than trivial AR

Subarterial VSDs >5 mm - closed regardless of AVP

Restrictive perimembranous VSD with AVP but without AI, surgery indications are less clear

Follow up regularly

Surgery is indicated only if AI develops

Elgamal MA et al . Ann Thorac Surg 68:1350-1355, 1999

Lun K et al. Am J Cardiol 87:1266-1270, 2001

Gabriel HM et al. J Am Coll Cardiol 39:1066-1071, 2002

Usually above the ventricular septal defect

Etiology:-

Progression of the pre-existing lesion

Acquired

Two types:-

Muscular

Fibromuscular

Three major structures are responsible

Posteriorly malaligned outlet septum

Septal deviation ( anteroseptal twist)Muscular protrusion of the left ventricular aspect of the septum

Anterolateral muscle bundleMuscular protrusion between LCC & AML- present normally in 40%

(Very rarely “Mitral arcade”)

Careful echo assessment of the LVOT should be performed in all cases of VSD before surgery

Moene RJ et al. Pediatr Cardiol 1982;2: 107–14.

Incidence - 5% to 22%

Rare in small & Moderate-size VSDs

Down syndrome – early development of PAH

No overall sex predilection

Keith JD et al. Heart Disease in Infancy and Childhood. 1978: 320–79.

Survival rate for patients with VSD by pulmonary artery systolic pressure

42 men and 37 women, 18 to 59 years (mean 34 yrs)

67 patients treated medically and 12 surgically

All patients were followed up for 1 month to 25 yrs ( mean 9yrs)

The solid line indicates a pressure less than 50 mm Hg (n = 36)

Dashed line indicates a pressure of 50 mm Hg or greater (n = 17)

Ellis JH 4th et al . Am Heart J. 1987;114:115-205

Eisenmenger complex, develops in 10% to 15%most commonly in the 2 nd & 3rddecades of life

common causes of death "sudden" or "unknown“

Development of pulmonary vascular disease after surgery depends on age at procedure is done

Infants with VSD and increased pulmonary artery pressure - repair between 3 and 12 months

18.7 per 10000 person-years in non operated cases

Operated VSD 7.3 per 10000 person-years

Higher in small defect & lower during childhood

Patients with a proven episode of endocarditis are considered at increased risk for recurrent infection so surgical closure may be recommended

Gersony WM et al.Circulation 1993; 87(Suppl. I):I-121–I-126.

Patients with VSD have a high incidence of arrhythmia

Ventricular tachycardias in 5.7%

Sudden death is 4.0%

SVT, mostly AF, is also prevalent

Age and pulmonary artery pressure are the best predictors of arrhythmias

The odds ratio of serious arrhythmias increases

1.51 for every 10-year increase in age

1.49 for 10mm Hg increase in mean PA pressure

Wolfe RR et al. Circulation. 1993;87:I89-101

Closing defect - soft S2, high frequency & shorter murmur

Increasing PVR : increased RV pulsations ,S2 loud & narrow split

Infundibular hypertrophy & resulting decreased L to R shunt : S2 decreases in intensity ,crescendo-decrescendo systolic murmur in the ULSB

Heart failure not controlled by medical therapy VSD should be operated with in 6 month of life

Qp/Qs is 2 or more surgical closure needed regardless of PA pressure

VSD with PVR more than 4 unit during 6-12 months

VSD with elevated PVR first seen after infancy

Moderate VSD with no size change in childhood

Right bundle branch block 33.3% undergoing transatrial repair

78.9% to 11% in repair via a right ventricular incision

Transpulmonary approach has the lowest incidence

Complete heart block in 1 to 2%

Pulmonary hypertension in (4% )

Sinus node dysfunction (4%)

Progressive aortic valve insufficiency (16%)Roos-Hesselin JW et al. Eur Heart J 2004;25:1057-1062.

Abe T et al . Jpn Circ J 1983; 47: 328–35.

Patent Ductus Arteriosus

Incidence of isolated PDA in term infants - 1 in 2,000

Female predominance - 3:1

High incidence- Prematurity, Maternal rubella

Genetic inheritance- Autosomal recessive with incomplete penetrance

Congestive heart failure

Infective endarteritis

Pulmonary vascular disease

Aneurysmal formation

Thromboembolism

Calcification

CHF resulting from an isolated PDA either develops in infancy or during adult life

HF in infancy usually occurs before of 3 mths of age

Initially left heart failure, later right heart failure

Good response to drugs initially, but is not maintained

Major cause of death in earlier era

Incidence - 0.45% to 1.0% per annum

Vegetations usually found at the PA end of the duct

May cause recurrent pulmonary embolism

Infection may also cause a ductal aneurysm

Cosh JA. Br Heart J 1957; 19: 13–22.

No definite data on incidence

“Differential cyanosis”

Eisenmenger patients do not tolerate PDA closure

Described either pre- or postnatally

Likely develops in the third trimester due to abnormal intimal cushion formation or elastin expression

Incidence varies from 1.5% to 8.8%

Dyamenahalli U et al. J Am Coll Cardiol 2000; 36: 262–9.

Jan SL et al. J Am Coll Cardiol 2002; 16: 342–7.

Complications

Thromboembolism

Dissection

Rupture

Tracheal compression

Left recurrent laryngeal nerve palsy

Pulmonary artery obstruction

Regression can occur, presumably due to thrombosis and subsequent organization

As many ducts will eventually close in premature infants approach is different - preterm infant Vs mature, child

Beyond infancy, closure reported in 0.6% per year

Medical therapy Treatment of Heart failure

Ductal closure with drugs

Surgical Therapy

Campbell M et al.Heart 1968;30:4–13.

Indomethacin Rates of success varying between 18% to 89%

Major determinants of success were gestational and postnatal age

Less chance of closure-Extreme prematurity, very low birth weight, and advanced postnatal age

The rate of re-opening is highest in the extreme premature( 1/3) & less than 1/10 those weighing 1500 g

Mahony et al. N Engl J Med 1982;306: 506-510.

Ibuprofen

Comparable rate of ductal closure to Indomethacin

Less effect on renal function

Increased incidence of Pulmonary hypertension

Gournay V et al. Lancet 2004;364:1939-1944.

Coils closure for <3 mm, >97% success, zero mortality

Larger PDAs - specialized devices

>98% complete closure rate at 6 months

Symptomatic moderate or large PDA with L to R shunt

Prior history endarteritis [class1]

Reasonable in small L to R shunt with normal-sized heart chambers when the PDA is audible by auscultation[IIa]

May be considered in bidirectional PDA shunt due to PAH and obstructive pulmonary vascular disease but reversible to pure L to R shunting with pulmonary vasodilators [IIb]

Incidence is 1 child per 1,500 live births

More frequent in females than males by about 2:1

Most ASDs occur sporadically; however, a few families have the defect as a genetic abnormality.

Mutation in-TBX5, NKX2.5 , GATA4, Myosin heavy chain 6

Samanek M et al. Pediatr Cardiol1999;20:411–7

The natural history depends on

Size of the defect

Rt. & Lt. ventricular diastolic compliance

Pulmonary-to-systemic vascular resistance

Hemodynamic/anatomic abnormalities resulting from a secundum atrial septal defect include

Right ventricular and atrial volume overload


Tricuspid valve and/or pulmonary valve regurgitation

Supraventricular tachyarrhythmias

Shunt direction & magnitude are variable and age dependent

In fetal life, RV noncompliance, a result of high pulmonary vascular resistance, allows nearly unidirectional right-to-left flow at the atrial level

Immediately after birth, with RV compliance comparable to that of the LV, there may be little net shunting through ASD

With the physiological fall in pulmonary vascular resistance, the RV thins, compliance increases, left-to-right shunt develops

With similarly sized ASDs, adults have larger shunts

.)

Four common clinical presentations of ASD in adult

Progressive shortness of breath with exertion


Atrial arrhythmia

stroke or other systemic ischemic event

Most infants with ASDs are asymptomatic

They may present at 6 to 8 weeks of age with a soft systolic ejection murmur and possibly a fixed and widely split S2

CHF rare in the first decades of life but it can become common once the patient is older than 40 yrs

Atrial arrhythmia may be the first presenting sign (13% in older than 40 & 52% in older than 60 yrs of age)

Prevention of Atrial arrhythmia is one of the reasons for repairing ASD in young asymptomatic patients

(Silversides CK et al. Heart. 2004;90:1194 –1198.)

Subsequent development of AF may depend more on the patient’s age at intervention and may occur despite surgery in patients > 25 years of age

St. John Sutton MG,et al. Circulation 1981;64:402-409.

Murphy JG, et al. N Engl J Med. 1990;323:1645–1650

Uncommon in ASD

Incidence is 5% to 10% of untreated ASDs

Predominantly in females

Sinus venosus ASDs have higher pulmonary artery pressures & resistances than patients with secundum

Vogel M et al. Heart 1999; 82: 30–3.

Craig and Selzer in 1968 studied 128 adult patients

Significant PAH developed in 22% of the series

This complication usually develops when the patient is between 20 and 40 years of age

Cherian et al studied 709 pts.of isolated ASD

PASP was > 50 mmHg in 17%

PAH was present in 13% of patients under 10 yrs

14% of those aged 11 to 20 years

Eisenmenger syndrome 9%

Craig RJ et al. Circulation 1968; 37: 805–15.

Cherian G et al. Am Heart J 1983; 105: 952–7.

Spontaneous closure most likely in

ASDs <7 to 8 mm

Younger age at diagnosis

A review of 101 infants -mean age of diagnosis 26 days average follow-up of 9 months.

Spontaneous closure in all 32 ASDs <3 mm

87% of 3- to 5-mm ASDs

80% of 5- to 8-mm ASDs

None of 4 infants with defects >8 mmRadzik D, et al. J Am Coll Cardiol. 1993;22:851-853.

A follow up of 84 children for 4 years showed a spontaneous closure or decreased size in

89% with a 4-mm ASD

79% with a 5- to 6-mm defect

7% with a defect >6 mm

Helgason H, et al. Pediatr Cardiol.1999;20:195-199.

Even infants with CHF can have spontaneous reduction in the size of the ASD years after the diagnosis

Occasionally, spontaneous closure will occur as late as 16 years.

Evidence of Rt. sided cardiac volume loading, Qp:Qs > 1.5:1

Symptomatic patients (principally exercise related)

PVR < 7 WU – closure is usually well tolerated Need to be mindful of elevated LVEPD

Pts may need diuretic therapy after closure

For PVR >7 WU and PA pressures >50% need to perform O2 and NO study

Elective repair frequently has been deferred until the child is at least 4 years of age.

Early operation has been recommended for those infants and young children who have unremitting heart failure or associated pulmonary hypertension

contraindication :- pulmonary hypertension with Rt. to Lt shunting at rest

Pulmonary vascular resistance of 14 WU

1. In large VSDs, the rate of decline in pulmonary vascular resistance after birth is delayed

2. In Down syndrome the development of CHF is delayed

3. CHF symptoms get worsen initially as pulmonary vascular resistance increases

4. Adults may present with new symptom of exercise intolerance

1. Usually moderate sized VSDs can be managed medically without surgical intervention during infancy

2. Intervention to close the VSD with PAH would shorter life expectancy than if the defect were left open

3. There is enlargement of LA, LV, RV and PA in moderate sized VSDs

4. Development of PAH may occur in as many as a quarter of patients with large defects who undergo surgery after 2 years of age.

1. In outlet VSD 25 % will close by 2yrs

2. Isolated VSD closure rate - 34% at 1 yr & 67% at 5 yr

3. Closure is rare in malaligned VSD

4. Closure more frequent in <10 yrs of age

1. Rare before 2 years

2. Prevalence 2% to 7%

3. Right coronary cusp prolapse extremely rare

4. Non-coronary cusp prolapse in perimembranous type

1. Posteriorly malaligned outlet septum

2. Septal deviation or anteroseptal twist

3. Anterolateral muscle bundle

4. Mitral arcade

1. Incidence higher in large defect

2. Incidence lower during childhood

3. Operated VSD 7.3 per 10000 person-years

4. Surgical closure may be recommended in Patients with a proven episode of endocarditis

1. 2 days

2. 2 weeks

3. 2 months

4. 6 months

5. 12 months

1. Anterolateral muscle bundle present normally in 60% of infants

2. Anteriorly malaligned outlet septum is a major cause

3. Usually occurs below the ventricular septal defect

4. Septal deviation is a muscular protrusion of the left ventricular aspect of the septum

1. It is a shunt from the pulmonary artery to the aorta in the fetus

2. Blood flow may take place from the aorta to the pulmonary artery after birth, prior its closing

3. Right to left blood flow increases with the first breath after birth due to falling pulmonary vascular resistance

4. The smooth muscle in its walls is sensitive to rising PO2

1. Breathlessness

2. Failure to thrive

3. Asymptomatic murmur

1. Recurrent chest infections

1. Arrhythmias

1. In large VSDs, the rate of decline in pulmonary vascular resistance after birth is delayed

2. In Down syndrome the development of CHF is delayed

3. CHF symptoms get worse initially as pulmonary vascular resistance increases

4. Adults may present with new symptom of exercise intolerance

1. Usually moderate sized VSDs can be managed medically without surgical intervention during infancy

2. Intervention to close the VSD with PAH would shorter life expectancy than if the defect were left open

3. There is enlargement of LA, LV, RV and PA in moderate sized VSDs.

4. Development of PAH may occur in as many as a quarter of patients with large defects who undergo surgery after 2 years of age.