Double Outlet Right Ventricle - Heart · Necropsy revealed a double outlet right ventricle....

Brit. Heart J., 1966, 28, 461.

Double Outlet Right VentricleA review of i6 cases with IO necropsy specimens

A. W. VENABLES AND P. E. CAMPBELL

From the Cardiac Investigatory Clinic and the Department ofPathology, Royal Children's Hospital, Melbourne, Australia

In so-called "double outlet right ventricle" bothaorta and pulmonary trunk arise wholly from theright ventricle. This relatively uncommon ab-normality is of interest anatomically and physio-logically and has considerable surgical significance.The condition has been described by various authorsincluding Witham (1957), Neufeld, DuShane, andEdwards (1961a), Neufeld et al. (1961b, 1962),and Morgan et al. (1962), with emphasis on thevariations in patterns dependent on the presenceor absence of significant pulmonary stenosis. Itsembryology has been discussed by Grant (1962) andby Van Mierop and Wiglesworth (1963).

This paper describes a further 16 cases of doubleoutlet right ventricle, 10 of which have come tonecropsy. These cases illustrate the variations inanatomy that occur in this condition and the clinicalsyndromes associated with it.

SUBJECTSNine patients have been seen since 1960 in the

Cardiac Investigatory Clinic of the Royal Children'sHospital, Melbourne, and at necropsy it has beenshown that they have double outlet right ventricle.An additional specimen was obtained from thepathology files of the hospital. Double outlet rightventricle has been diagnosed by special investigationin 6 other surviving patients. Patients in whom thepulmonary trunk overrides a ventricular septaldefect have been excluded.The clinical features and other findings of the

patients who died with double outlet right ventricleand who were subjected to necropsy will bedescribed briefly. The material is arranged withregard to variations in anatomical relationshipbetween the rings of the mitral, aortic, and pulmon-ary valves and the ventricular septal defect. Table Isummarizes these findings. Details of patients inwhom the diagnosis is based on investigatory

Received June 16, 1965.

findings alone are given in Table II. The investi-gatory findings are included in Table III. Two ofthese patients have died. In neither was necropsyperformed.

Group IIn these 5 patients the anatomical situation is an

exaggeration of that in the tetralogy of Fallot or inthe Eisenmenger complex. The aortic and mitralvalves are contiguous through the ventricular septaldefect, and the pulmonary trunk is normally situatedbeyond the crista.

Case 1. A boy was first seen in 1959 at the age of 8months, having failed to thrive. He was acyanotic witha diffuse loud systolic murmur. There was a thrill atthe aortic area. Pulmonary closure was not accentuated,and no apical mid-diastolic murmur was heard. Radio-graphy showed cardiac enlargement and pulmonaryplethora, while the electrocardiogram showed right axisdeviation and probable left ventricular hypertrophy.Cardiac catheterization at that time showed a smallishleft-to-right shunt at ventricular level with mild pul-monary valve stenosis (Table III). There was no arterialdesaturation. Severe cardiac failure developed at theage of 3 years and 10 months. Further investigation atthe age of 3j years showed equalization of right ventri-cular and aortic systolic pressures, minimal, if any, left-to-right shunting, and evidence of mild pulmonary valvestenosis with moderate pulmonary arterial hypertension(Table III). The aortic catheter consistently enteredthe right ventricle but not the left. Direct left ventri-cular puncture was not attempted, despite a clinicaldiagnosis of left ventricular outflow obstruction, as itwas felt that the boy's condition precluded any attemptat open-heart surgery.Necropsy revealed a double outlet right ventricle.

The pulmonary valve was normally placed, being sepa-rated from the aortic valve by a narrow cristal band(Fig. IA, B). The aorta arose wholly from the rightventricle. The junction between the mitral and tri-cuspid valve rings formed part of the boundary of theventricular septal defect, approximately 7 by 18 mm. insize, which provided the only outlet for the left ventricle

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Venables and Campbell

TABLE I

CASES WITH NECROPSY

Cyanosis

Nil

Moderate

Mild

Nil definite(jaundiced)

Progressivefrom infancy;ultimately deep

Mild to moderate*

Deep

Mild

Minimal

Marked

Pulmonary trunk Ventricular septal defect

Normally situated

Normally situated

Normally situated

Normally situated

Normally situated

Normelly situated

Normally situated

Transposed

Possiblytransposed

Probably normallysituated

SubaorticSubaortic

Subaortic

Subaortic

Subaortic

Subaortic; tissue betweenmitral and aortic valves

Subaortic; tissue betweenmitral and aortic valves

Two defects, onesubpulmonary

Large subpulmonary defect

Two defects, one largelyoccluded

Other major defects

Bicuspid, moderately stenoticpulmonary valve

Infundibular and pulmonaryvalve stenosis; secundumASD

Secundum ASD; A-V canalwith hypoplastic mitralvalve component, small leftventricular cavity

Secundum ASD; hypoplasticmitral valve and left ven-tricle

Severe infundibular stenosis

Anomalous chordalattachment

Infundibular and pulmonaryvalve stenosis

Anomalous chordalattachment

ASD; complete interruptionof aortic arch

Hypoplastic left lung

* Specimen from Pathology Department files. Notes record cyanosis during admissions with pneumonia and heart failure.t Death precipitated by operation or by investigation.

TABLE IIPATIENTS SURVIVING OR WITHOUT NECROPSY FINDINGS

Case No. and sex Age at, and year Cyanosis Associated lesions Courseof, investigation

11 M 17 mth., 1962 Mild Left-to-right shunt at atrial level Died, aged 3 yr., no necropsy12 F 2 yr., 1962 Deep Skeletal abnormalities; absence of hepatic Satisfactoryaorto-pulmonaryanastomosis

IVC with azygos continuation; pul- at 3 yr.monary valve stenosis

13 F 3 yr., 1963 Mild _ Surgery not attempted14 M 2 mth., 1963 Deep Severe infundibular stenosis Aorto-pulmonary anastomosis at 5 mth.

poorly tolerated15 M 3 mth., 1964 Mild Atrial septal defect with large left-to-right Pulmonary artery bandirg without effect

shunt on haemodynamics16 M 8 yr., 1965 Deep Severe infundibular (subpulmonary) sten- Death following intracardiac surgery;

osis; apparent transposition of great necropsy not permittedvessels

TABLE IIICARDIAC CATHETERIZATION FINDINGS

Oxygen saturations (%) Pressures (mm. Hg)

Case Age Sup. R. R. Pulm. L. Aorta Ear-, R. R. Pulm. L. L. Aorta FANo. vena atrium ventr. art. atrium piece atrium ventr. art. atrium ventr.cava aru et. at tim pee aru et. at tim vnr

1 8 mth. 55 71 70 97 55/0 25/103 yr. 59 53 65 93 90/0 50/30 90/55

2 5 yr. 64 67 71 84* 80 80/0 11 100/03 6 wk. 48 76 70 74 77 95/5 80/604 10 dy. 34 91 86 45/55 10 mth. 15 22 t 110/3 1I9 3 wk. 40 76 78 87 93 87§ 97 10 90/20 17 80/50

mean mean11 17 mth. 59 78 75 75 98 87 4 90/5 82/42 13

mean mean12 2 yr. 50 63 63 92 88 105/2 1113 3 yr. 69 65 92 90 5 100/0 100/50 90/5814 2 mth. 26 26 45 96 90/10A 1115 3 mth. 54 80 88 97 7 75/10 - 12 100/10

mean mean3 mth. 38 63 80 75 93* 84 100/0 40/20¶ 90/60

16 8 yr. 62 66 80 85 100 100/10 16/6 i(infundibulum 40/-4)I_I_I__

* PV 98 per cent. t PV 96 per cent. * PV 93 per cent. 5 Wedged PA 97 per cent. 11 Angiography confirmed obstruction to outflowto pulmonary artery (PA not entered by catheter). ¶ After banding pulmonary trunk.

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Case No. and sex

1 M

2 M

3 F

4 F

5

6 M

7 M

8 M

9 F

10 F

Age at death

3 yr. 10 mth.

6yr.

1 yr. 9 mth.

2 wk.

F 10 mth.

3 yr. 10 mth.

9 yr.

4 mth.t

31 wk.t6 wk.t



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Double Outlet Right Ventricle

Diagram: a = aortic valve; p = pulmonaryvalve; t = tricuspid valve; v = ventricular

septal defect.

FIG. 1.-(A) Right ventricular cavity (B) Right ventricular cavity viewed fromviewed from anterior aspect showing below. Aortic valve visible behind crista,apparently normal relationship of adjacent to tricuspid valve.

aorta and pulmonary trunk.

FIG. 1.-(C) Left ventricular cavity showing ventricular septaldefect adjacent to mitral valve.

Diagram: m= mitral valve; v=ventricular septaldefect; Isvc=left superior vena cava; p=left pul-

monary artery.

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(Fig. 1G). The aortic valve was adjacent to the atrio-ventricular valves, and the aortic cusp of the mitralvalve was contiguous with the aortic valve through theseptal defect. Both ventricles were dilated, particularlythe right. The left ventricular wall measured 7 mm.and the right 8 to 10 mm. in thickness. The pulmonaryvalve was bicuspid and moderately stenotic.

Case 2. A boy was first seen during 1962, aged 5years, with features suggestive of the tetralogy ofFallot with moderate cyanosis. The electrocardiogramshowed right axis deviation and right ventricularhypertrophy. Investigation showed infundibular sten-osis with a pulmonary trunk of moderate width. Therewas an interatrial communication (Table III). Theaorta appeared conspicuously dextraposed with a leftarch. Thoracotomy was performed with the object oftotal repair, but the aorta appeared to arise wholly fromthe right ventricle and this procedure was not attempted.Subsequently an anastomosis was made between thedescending aorta and the left pulmonary artery. Follow-ing this, his condition became unsatisfactory with cardiacenlargement and evidence of failure. The anastomosiswas narrowed at a further operation 6 weeks later, butheart failure persisted and he died 7 months after theinitial shunt procedure. During this time clinicalfeatures suggested that pulmonary flow was not con-

spicuously increased.Necropsy revealed a secundum atrial septal defect, and

a prominent inferior vena caval valve. The aortaarose wholly from the right ventricle, being separatedfrom the normally situated pulmonary valve by the crista.The aortic valve was contiguous with the mitral valvethrough a ventricular septal defect approximately 15 mm.in diameter that had as part of its boundary the junctionof tricuspid and mitral rings. There was a shortinfundibular stenosis with a bicuspid pulmonary valvewhich was quite severely narrowed. There was a patentaorto-pulmonary anastomosis approximately 5 mm. indiameter. The left ventricle was dilated with a wallthickness of 10 mm., while the right ventricle was clearlyhypertrophic with a thickness of 12 mm.

Case 3. A female infant was seen first in April 1962,when aged 1 month, with cardiac failure and signs ofpulmonary hypertension with considerable cardiacenlargement and pulmonary plethora. There were alsomultiple skeletal abnormalities, with hemivertebre andfused ribs. The electrocardiogram showed markedright ventricular hypertrophy with an apparent QRcomplex in the right chest leads. Investigations showedsubstantial left-to-right shunt at atrial level with rightventricular hypertension (Table III). She thrivedpoorly and had persistent dyspneea. Death occurredat 21 months apparently from inhalation of vomitusassociated with a fit.Necropsy revealed dilatation of the right atrium with a

large secundum atrial septal defect and a primum atrialseptal defect. Both main trunks arose from the rightventricle, the pulmonary artery being normally situatedanterior to the crista. The aortic ring was contiguouswith a common atrio-ventricular valve whose mitralcomponent was very hypoplastic. A ventricular septal

defect provided egress from the left ventricle. Thisdefect was roofed by the fused anterior and posteriorleaflets of the common atrio-ventricular valve. Theright ventricle was dilated and hypertrophic, while theleft ventricle was relatively small with the cavity de-creased in size by septal bulging.

Case 4. A female infant was admitted in March 1964at the age of 5 days with cardiac failure. Her conditionprogressively deteriorated, and she died at the age of 2weeks. The radiograph showed marked cardiac en-largement and apparent pulmonary venous engorge-ment. The electrocardiogram showed right ventriculardominance with a small "q" wave in the right-sidedchest leads. Cardiac catheterization demonstrated aleft-to-right shunt at atrial level with right ventricularhypertension (Table III). Both aorta and pulmonaryartery filled from an anteriorly-placed ventricle intowhich radio-opaque dye was injected for selective angio-cardiography.Necropsy revealed a secundum atrial septal defect.

The pulmonary artery was normally placed. The aortaalso arose from the right ventricle, its root being separatedfrom the pulmonary valve by cristal tissue. Mitral andtricuspid valves were contiguous through a small ven-tricular septal defect which provided the only outlet forthe left ventricle. The aortic ring was in virtual con-tinuity with the mitral ring through the defect. Themitral valve was narrow and the left ventricle somewhathypoplastic.

Case 5. A female infant was seen first in February1964 at 4 weeks of age. There was no cyanosis. A loudprecordial systolic murmur radiated to the aortic area.There was a probable right aortic arch and the lungfields were somewhat dry. The electrocardiogramsuggested excess left ventricular activity. During sub-sequent months cyanosis became progressively moremarked and disability more severe, but the murmur didnot change. At 10 months the ear-piece saturation was56 per cent at rest. Selective right ventricular angio-graphy showed severe infundibular stenosis with aventricular septal defect, the aorta arising wholly fromthe right ventricle. Necropsy confirmed these findingstogether with severe pulmonary valve stenosis. Theaortic and mitral valves were contiguous as in thetetralogy of Fallot, the aortic root simply being dextra-posed fully across to the right ventricular side of theseptum.

Group IIThis group comprises 2 patients in whom the

pulmonary trunk was normally situated with aventricular septal defect proximal to the cristaand close to the atrio-ventricular valves. Incontrast to Group I the aortic and mitral valves wereseparated by an obvious band of tissue.

Case 6. This boy died in 1954 at the age of 3 yearsof congestive cardiac failure, having previously sufferedfrom recurrent lower respiratory tract infection associ-

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FIG. 2.-(Case 6). Right ventricular cavity viewed fromanterior aspect. Aortic valve separated from septal defect

and atrio-ventricular valves by band of muscle.

ated with known congenital heart disease. Necropsyrevealed double outlet right ventricle.The tricuspid ring was normal but the lateral cusp of

the tricuspid valve was small. The anterior and septalcusps fused medially and formed the posterior margin ofa ventricular septal defect, the superior margin of whichwas formed by the aortic cusp of the mitral valve(Fig. 2). Both aorta and pulmonary trunk arose fromthe somewhat thickened right ventricle, the pulmonarytrunk lying normally beyond a hypertrophied crista.The aortic root was separated from the aortic cusp ofthe mitral valve by a band of muscle approximately10 mm. in width. The endocardium overlying thismuscle band was thickened and fibro-elastic. The leftventricle was hypertrophied and dilated, the only egressbeing via the ventricular septal defect. The mitralvalve was somewhat thickened with short chorde.

Case 7. A boy aged 9 years, previously investigatedand thought to have a severe form of the tetralogy ofFallot, died suddenly at home. Necropsy confirmed thepresence of severe localized infundibular stenosis withcalcification. There was a narrow bicuspid pulmonaryvalve and the pulmonary trunk was small. The aortaarose wholly from the right ventricle proximal to thecrista, its root being separated by a band of muscleapproximately 10 mm. wide from the aortic cusp of themitral valve, where that cusp met the tricuspid valve inthe edge of the ventricular septal defect.

Diagram: a = aorta; p = pulmonary trunk; mb = muscleband; t = tricuspid valve; v= ventricular septal defect.

Group IIIIn this patient there appeared to be transposition

of the great vessels complicating the double outletright ventricle.

Case 8. A male child presented with cardiac failureat the age of 4 months. He had a loud precordialsystolic murmur with a thrill and was mildly cyanosed.Radiography showed considerable cardiac enlargementwith pulmonary plethora, while the electrocardiogramshowed right axis deviation, biventricular hypertrophy,and right atrial hypertrophy. Death resulted fromcerebral cedema following a venous angiocardiogram(Case 11, Venables and Hiller, 1963).Necropsy showed a dilated right atrium with multiple

small perforations in the floor of the fossa ovalis.There was a double outlet right ventricle. The aorticroot was transposed, lying beyond the crista, while thepulmonary valve was situated more posteriorly, lyingclose to the tricuspid valve, pulmonary valve and mitralvalve being contiguous through a ventricular septaldefect (Fig. 3A, B). Across the right ventricular aspectof this ventricular septal defect ran a thick muscularband which extended from the apex of the right ventricleto just below and lateral to the pulmonary valve dividingthe defect into two substantial components, the medialof which was that related to the pulmonary trunk, asdescribed above. The lateral defect was partly occludedon its left ventricular aspect by anomalous attachment ofthe mitral valve to the related part of the septum. Theleft ventricle was dilated and the right ventriclemoderately hypertrophied.

Group IVIn these two cases the anatomical situation is

more difficult to define. In one, there was a largesubpulmonary ventricular septal defect. In the

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A BFIG. 3.-(Case 8). Right ventricular cavity viewed from anterior aspect.

(A) Right ventricle partly unroofed showing relationship of aorta and pulmonarytrunk.

(B) Right ventricle wholly unroofed showing two components of ventricular septaldefect. Pulmonary valve is continuous with mitral valve through medial defect

adjacent to tricuspid valve.

other there were 2 ventricular septal defects, of tionship of tricwhich the major functional defect lay in the mus- and ventriculacular septum well away from either aorta or ventricle. Th4pulmonary trunk. septal defect.

tissue was conti,,Case 9. A female infant developed cardiac failure band of muscle

at the age of 1 week. There were no significant mur- ary ring and almurs. The ear-piece saturation was 91 per cent at restin air, rising to 97 per cent in oxygen. The radiograph Case 10. Ashowed cardiac enlargement and pulmonary plethora. at the age of 2The electrocardiogram was within normal limits for age. birth, and app

Investigation suggested the presence of both an atrial tion was 72 pseptal defect and a ventricular septal defect, with right systolic murmuventricular systolic pressures of systemic order. The enlargement arcatheter passed from the pulmonary trunk to the des- the electrocarccending aorta where the saturation equalled that in the ponderance aspulmonary artery (Table III). Death occurred at leads II, III,thoracotomy during the fourth week of life when an interpreted atattempt was being made to reduce the left-to-right monary trunkshunt. left ventricularNecropsy revealed an atrial septal defect of the and somewhat

foramen ovale type, a double outlet right ventricle, and The baby dicomplete interruption of the aortic arch beyond the left weeks. Necrolsubclavian artery. The descending aorta was continu- aorta arising frous with the pulmonary trunk. Fig. 4 shows the rela- separated from

Diagram: a = aorta; p = pulmonary trunk;t = tricuspid valve; v= ventricular septaldefect; mb =muscle band across defect.

uspid valve, aortic root, pulmonary trunk,r septal defect as viewed from the righttre was a large subpulmonary ventricularThrough this defect the tricuspid valveiguous with the mitral valve. There was abetween the mitral ring and the pulmon-[so between tricuspid and aortic rings.

female infant presented in January 1961weeks with cyanosis and dyspnoea sincearent cardiac failure. Ear-piece satura-oer cent. There was a faint precordialir. Radiography showed marked cardiacnd moderate pulmonary plethora, whilediogram showed right ventricular pre-;sociated with dominant "s" waves inand aVF. A venous angiogram, mis-the time, showed the aorta and pul-filling from the right ventricle withoutifilling, the aorta being placed anteriorlymedially.ied during thoracotomy at the age of 6ipsy revealed a rather anteriorly placedrom the right ventricle. The aorta wasi the tricuspid valve by a wide band of

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Diagram: a= aorta; p = pulmonary trunk; t= tricuspidvalve; v= ventricular septal defect.

FIG. 4.-(Case 9). Right ventricular cavity viewed fromanterior aspect. Large subpulmonary ventricular septal

defect.

muscle which was a continuation of the crista supraven-tricularis. The pulmonary trunk also arose from theright ventricle, its valve being separated from the aorticroot and from the right ventricular inflow by the crista(Fig. 5A). The right and particularly the left ventriclewere both dilated. The only effective egress from theleft ventricle was via a septal defect approximately 10 x 7mm. situated in the muscular septum well away from thetricuspid valve below the crista supraventricularis (Fig.5B). An additional defect in the region of the atrio-ventricular valves when viewed from the left ventriclewas virtually sealed by an adherent somewhat anomalousmitral valve. The right ventricular opening of the non-functional septal defect was small and some distancebelow the pVilmonary valve ring. The left lung washypoplastic with a single pulmonary vein.

Group VDetails of the surviving cases, 11 to 16 inclusive,

are summarized in Table II.

DISCUSSIONAnatomical Findings. Cases of double outlet

right ventricle have been classified in two ways,

depending first on the presence of significant pul-monary stenosis (Witham, 1957; Neufeld et al.,2H

1961a, b, 1962; Morgan et al., 1962), and second onthe relation between the aortic and mitral valves(Neufeld et al., 1961b, 1962).Neufeld et al. (1961b) described two subgroups

of double outlet right ventricle without pulmonarystenosis. In 3 of 5 specimens, the aortic leaflet ofthe mitral valve was long and ran through the roof ofthe ventricular septal defect to become continuouswith the aortic valve. In the other 2 specimens,the aortic and mitral valves were separated by aband of muscle described as part of the cristasupraventricularis. The ventricular septal de-fects in these individuals were situated proximal tothe crista, adjacent to the atrio-ventricular valves.In the later, different, series of Neufeld et al.(1962), the aortic valve was continuous with themitral valve in only 1 of the 6 specimens withoutpulmonary stenosis and with a septal defect in thisposition. Continuity of aortic and mitral valveswas present in only 1 of 6 cases with double outletright ventricle, complicated by pulmonary stenosis(Neufeld et al., 1961a). In the others the aorticvalve was noted to be above the horizontal limb ofthe crista supraventricularis which separated theaortic valve from the ventricular septal defect andfrom the atrio-ventricular valve tissue.Van Mierop and Wiglesworth (1963) also referred

to these two anatomical types in discussing the em-bryology of double outlet right ventricle. WhereasNeufeld et al. (1962) merely stated that "dis-continuity of the mitral and aortic valve tissue is theusual finding" in double outlet right ventriclewithout pulmonary stenosis, Van Mierop and

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FIG. 5.-(Case 10).(A) Right ventricular cavity viewed from (B) Left ventricular cavity showing major

anterior aspect. (functional) ventricular septal defect.

Diagram: a= aorta; p = pulmonary trunk; t= tricuspid valve;v =virtually non-functioning ventricular septal defect; vl=

major ventricular septal defect.

Wiglesworth (1963) regarded the type with con-tiguous aortic and mitral rings as merely an extremeform of the Eisenmenger complex, or ofthe tetralogyof Fallot if there were significant pulmonarystenosis, embryologically different from the typein which aortic and mitral valves are clearly separatedby muscle. These authors referred to this separa-ting tissue as persistence of the bulboventricularflange. Despite their observations they admitted

Diagram; mv= mitral valve; v= virtually non-functioningventricular septal defect; vl=major ventricular septal defect.

the functional identity of the two types, which canonly be differentiated by direct observation of thedefect and the aortic ring at operation or necropsy.

In the present series there were 7 hearts in whichthe pulmonary trunk was clearly situated in normalrelation to the crista and to the other valves (Cases1 to 7). Three exhibited severe outflow tractstenosis of mixed infundibular and valvular type,while one had a moderately stenotic bicuspid

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pulmonary valve. In 4 specimens there was con-tinuity between the mitral and aortic valves, and inone with a persistent common atrio-ventricularcanal there was continuity between the canal valveand the aortic valve. In the remaining 2 specimens(Cases 6 and 7), the aortic valve was separated fromthe mitral valve by a flat band of muscle approxi-mately 10 mm. wide. In one of these there wassevere pulmonary stenosis. Thus all but 2 of thesespecimens appear to be examples of severe aorticdextroposition of the Eisenmenger and Fallot typesin which the aorta arises wholly from the rightventricle. In all 7, the septal defect was proximalto the crista.

In 3 hearts the anatomy was more complex. InCase 8 the great vessels appeared certainly to betransposed with the aorta lying beyond the crista,the pulmonary trunk having an essentially postero-lateral relationship to the aorta, with its valve closeto the atrio-ventricular valves. One component ofthe ventricular septal defect was subpulmonary inposition and there was a close relation betweenpulmonary and mitral valves (Fig. 3A and B).Grant (1962) emphasized the presence in trans-position of the great vessels of an intimate relationbetween the pulmonary and mitral rings in contrastto the normal close relation of aortic and mitralrings. By this criterion Case 8 exhibits transpositionindependent of any consideration or identificationof exact right ventricular architecture. In Case 9(Fig. 4) the aorta arose from a muscular tunnelmedial to the pulmonary trunk and the vessels wereless definitely transposed. The septal defect wassub-pulmonary (Fig. 4) but without contiguity ofpulmonary and mitral valves. Subpulmonaryseptal defects occur without transposition, andCase 9 probably fits best into this category. Neufeldet al. (1962) described 3 cases of double outletright ventricle with ventricular septal defects lyingabove the crista supraventricularis in a subpul-monary position. In one the defect extended be-low the aortic valve which was continuous with theaortic cusp of the mitral valve. In the othersabsence of continuity between aortic and mitralvalves was mentioned without reference to possiblerelationship between pulmonary and mitral valves.There is a striking similarity between the rightventricular aspect of their Case 8 as illustrated andFig. 4 of this report. Clear-cut transposition wasstated to be present in the case with persistentcommon atrio-ventricular canal and pulmonarystenosis described by Neufeld et al. (1961a).

In Case 10 of this report the main trunks wereprobably not transposed. There were two ven-tricular septal defects of which one was probably oflittle functional significance. This smaller defect

passed from below the aortic cusp of the mitralvalve on the left ventricular aspect of the septumto a point a short distance below the pulmonaryvalve. The major defect was lower in the muscularseptum. As in Case 9, there was no direct relationbetween the mitral valve and either semilunar valve.This situation was in fact shared by the two cases(Cases 6 and 7) of Group II. Grant (1962)acknowledged the occurrence in some examples ofdouble outlet right ventricle of this departurefrom his scheme of valve ring relationships.

In the specimens described in this report, therewere three categories of valve relationships. Anintimate relation between aortic and mitral valves,as in the normal heart, was most common, but in onespecimen there was a close relation between pul-monary and mitral rings, as in complete trans-position. In 4 specimens there was no intimaterelation between the mitral valve and either theaortic or pulmonary valves. These patterns providean important method of classification of the anatomyof the condition.

Hemodynamic Disturbances. The presence of asubpulmonary ventricular septal defect has physio-logical implications that are independent of whetheror not the great vessels appear to be anatomicallytransposed. In the more usual form of doubleoutlet right ventricle where the aorta is closely orrelatively closely related to the septal defect, thehiemodynamic situation is frequently similar to thatof large ventricular septal defect. Neufeld et al.(1961b) pointed out that the impression of directcontinuity of the aorta with the left ventricle, givenby opening these specimens from left ventricle toaorta, was an artefact, but despite this the aorta re-ceives left ventricular blood. Unless there issignificant pulmonary stenosis or pulmonary vas-cular disease there appears in many cases to be littleentry of systemic venous blood from the rightventricle into the aorta, and arterial saturations areoften relatively normal. There is obligatory rightventricular hypertension with substantial left-to-right shunt. On the other hand if the septaldefect is subpulmonary, the left ventricle ejectsdirectly into the pulmonary artery and the aortareceives largely systemic venous blood, so thatsubstantial cyanosis is combined with considerableincrease in pulmonary flow and very high oxygensaturations in the pulmonary artery. The situa-tion is heemodynamically like that of many cases ofcomplete transposition of the great vessels. Whenthe pulmonary trunk is normally situated and theseptal defect is subpulmonary, the abnormality isheld by Neufeld et al. (1962) and by Van Mieropand Wiglesworth (1963) to represent the Taussig-

LIMARY1F1PT11FPrr ro%o%

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Bing syndrome in which the pulmonary trunk ismore commonly described as overriding the ven-tricular septum above the defect.

Cases 8 and 9 of the present report exhibitsubpulmonary defects. Case 9 (Fig. 4) moreclosely resembles the Taussig-Bing syndrome thanCase 8 (Fig. 3) in which the situation appears to beactually more closely related to transposition withventricular septal defect and overriding pulmonaryartery. In both cases, however, the pulmonaryartery is arising wholly from the right ventricleand not overriding. It is of interest that neitherof these patients in fact had deep cyanosis. InCase 9 this appears to have been due to a largeleft-to-right shunt at atrial level resulting in a highoxygen saturation of blood entering the rightventricle from the right atrium. Case 8 wasstudied only by venous angiography so that thehmmodynamic situation was not documented, butit is possible that the second ventricular septaldefect or the multiple small atrial defects mayhave influenced the aortic saturation.The only patient in the series with deep cyanosis

without severe pulmonary stenosis was Case 10.In this specimen the functional ventricular septaldefect was a considerable distance from both aortaand pulmonary artery, so that it is difficult to accountfor the aortic saturation in terms of specific direc-tion of the stream of left ventricular blood.As already stated, in the common forms of double

outlet right ventricle the left ventricle ejects blooddirectly into the aorta as in simple ventricularseptal defect with normal aortic root. Complica-tion by severe pulmonary stenosis or pulmonaryvascular obstruction results in diversion of part ofthe systemic venous return from the right ventricleto the aorta with consequent arterial desaturationand cyanosis. In double outlet right ventricle,however, the left ventricular output has all to passthrough the septal defect, which occupies a relation-ship to the ejected blood comparable to the obstruc-tive tissue in the syndrome of ventricular septaldefect with subaortic stenosis situated at the lowerlevel of the defect. The septal defect may be ob-structive both with normal or reduced left ventricu-lar output and with the increased output presentwhen pulmonary flow is increased naturally or asthe result of aorto-pulmonary anastomosis. Mirow-ski, Mehrizi, and Taussig (1963) emphasized thecontribution of obstructive left ventricular loadingto the electrocardiographic picture of doubleoutlet right ventricle with significant pulmonarystenosis, while Taussig (1960) has commented onthe poor tolerance of these patients for shuntprocedures. Both of these phenomena are likelyto be due to interference with left ventricular out-

flow. Shunts were poorly tolerated in Case 2 andin the surviving Case 14 in spite of lack of clinicalevidence of excessive pulmonary flow. In Case 1the clinical course could not be explained in termsof the amount of shunt and the degree of pulmonarystenosis demonstrated, and aortic stenosis wasactually thought to be the additional responsiblefactor.The relationship of the septal defect to the left

ventricular outflow stream is probably also respon-sible at times for the murmurs observed in somepatients with this condition. Murmurs suggestiveof aortic stenosis were described in cases of doubleoutlet right ventricle without pulmonary stenosisby Morgan et al. (1962) who commented on"aortic outlet narrowing" in three patients withsuch murmurs. In Case 1 the murmur suggestedthe presence of aortic stenosis, but at necropsy therewas no aortic valve abnormality and no "aorticoutlet narrowing", the aortic valve being contiguouswith the mitral valve. The septal defect appearedto have provided obstruction to outflow from theleft ventricle and was probably the site of origin ofthe murmur. In Case 5 a loud prtecordial systolicmurmur, which persisted when pulmonary flowappeared to have become very small indeed, againseems likely to have been generated at the septaldefect.

Substantial left-to-right shunt was present atatrial level in 5 of the patients who were catheter-ized (Table III). In 3 the mean left atrial pressureexceeded the mean right atrial pressure by 5 to9 mm. mercury. The 3 who died had large atrialseptal defects. In Case 15 the persistence of theatrial shunt after effective pulmonary artery bandingand the findings at subsequent angiographic studiesalso indicated that there was a true atrial septaldefect rather than a dilated foramen ovale, permit-ting left-to-right shunt consequent on dilatation ofthe left atrium secondary to increased pulmonaryflow, as described by Rudolph et al. (1958). In twoof those who died there was evidence of obstructionto left ventricular filling that would have potentiatedthe shunt.

Electrocardiograms. Neufeld et al. (1961b) des-cribed an electrocardiographic pattern similar to thatof persistent common atrio-ventricular canal in 7 of8 patients without pulmonary stenosis. In theseries ofNeufeld et al. (1962) this pattern occurred insimilar patients whose ventricular septal defectslay below the crista. This pattern was not dis-cussed in the cases with pulmonary stenosis ofNeufeld et al. (1961a) and of Mirowski et al. (1963).The findings in the present series showed no con-stant pattern but do not negate the possible value

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of such an electrocardiogram as a diagnostic clue inapparent ventricular septal defect with pulmonaryhypertension.

Diagnosis. The possibility of double outletright ventricle arises in all patients with apparentventricular septal defect with right ventricularhypertension of systemic level, and in patients whoappear to have the tetralogy of Fallot with extremedextroposition of the aorta. The special surgicalproblems of the condition (Kirklin, Harp, andMcGoon, 1964) make it important that the ana-tomical situation be recognized by appropriateinvestigatory procedures, and that possible leftventricular outflow obstruction be assessed when-ever indicated. The diagnosis may be suggestedby the anterior position of the aortic root, by verticalorientation ofthat structure, as suggested by Morganet al. (1962), or by consistent passage of an aorticcatheter into the right but not the left ventricle.The diagnosis must, however, be confirmed byappropriate biplane angiography demonstratingthe relationship of the great vessels to the rightventricle, remembering the dilution effects whichmay result from selective left ventricular ejectionto one or other main trunk (Neufeld et al., 1962).In one case in the present series selective leftventricular angiography performed via the foramenovale demonstrated ejection of the left ventricularcontents via the ventricular septal defect to theright ventricle from which both main trunks arose.

Investigation will reveal double outlet right ven-tricle, possibly complicated by transposition, insome infants presenting arterial desaturation withincreased pulmonary flow but with no clear clinicalindication of the nature of the underlying lesion.

SUMMARY

Sixteen cases of double outlet right ventricleseen at the Royal Children's Hospital, Melbourne,are recorded. The diagnosis was based on necropsyin 10 cases and on investigatory findings alone in6 cases.The patterns of the anatomy of the condition are

illustrated by the 10 necropsy specimens. In 5specimens there was a normal relation betweenmitral and aortic valve tissue through the ventricularseptal defect that provided the only egress from theleft ventricle. In one specimen there was a similarclose relation between pulmonary and mitralvalves, as in transposition of the great vessels. Inthe remaining 4 specimens there was no contiguitybetween either the aortic or pulmonary valves andthe atrio-ventricular valve tissue. These relation-ships appear toprovidean important method of classi-

fying specimens of double outlet right ventricle inaddition to the two other methods employed, relatedto the presence or absence ofpulmonary stenosis andto the relationship of the ventricular septal defectto the aorta or pulmonary artery. The details ofthe anatomy have considerable relevance to thepossibility of intracardiac repair, but final assess-ment can only be made by direct inspection of theinterior of the heart.The patterns of physiological disturbance in

double outlet right ventricle are also discussed inrelation to the material reported. The site and sizeof the ventricular septal defect are of considerableimportance. Selective direction of left ventricularoutflow to one or other great vessel greatly influencessystemic arterial saturation, while obstruction toleft ventricular outflow by the septal defect affectsleft ventricular loading.

REFERENCESGrant, R. P. (1962). The morphogenesis of transposition of

the great vessels. Circulation, 26, 819.Kirklin, J. W., Harp, R. A., and McGoon, D. C. (1964).

Surgical treatment of origin of both vessels from rightventricle, including cases of pulmonary stenosis.J. thorac. cardiovasc. Surg., 48, 1026.

Mirowski, M., Mehrizi, A., and Taussig, H. B. (1963).The electrocardiogram in patients with both great vesselsarising from the right ventricle combined with pulmon-ary stenosis. An analysis of 22 cases with specialreference to the differential diagnosis from the tetralogyof Fallot. Circulation, 28, 1116.

Morgan, J., Pitman, R., Goodwin, J. F., Steiner, R. E., andHoliman, A. (1962). Anomalies of the aorta andpulmonary arteries complicating ventricular septaldefect. Brit. Heart_J., 24, 279.

Neufeld, H. N., DuShane, J. W., and Edwards, J. E. (1961a).Origin of both great vessels from the right ventricle.II. With pulmonary stenosis. Circulation, 23, 603.--, Wood, E. H., Kirklin, J. W., and Edwards, J. E.

(1961b). Origin of both great vessels from the rightventricle. I. Without pulmonary stenosis. Circulation,23, 399.

, Lucas, R. V., Jr., Lester, R. G., Adams, P., Jr., Anderson,R. C., and Edwards, J. E. (1962). Origin of both greatvessels from the right ventricle without pulmonarystenosis. Brit. Heart,J., 24, 393.

Rudolph, A. M., Mayer, F. E., Nadas, A. S., and Gross, R. E.(1958). Patent ductus arteriosus. A clinical andhemodynamic study of 23 patients in the first year oflife. Pediatrics, 22, 892.

Taussig, H. B. (1960). Congenital Malformations of the Heart,2nd ed., Vol. 2, p. 73. (The Commonwealth Fund),Harvard University Press, Cambridge, Massachusetts.

Van Mierop, L. H. S., and Wiglesworth, F. W. (1963).Pathogenesis of transposition complexes. II. Anoma-lies due to faulty transfer of the posterior great artery.Amer. J. Cardiol., 12, 226.

Venables, A. W., and Hiller, H. G. (1963). Complicationsof cardiac investigation. Brit. Heart J., 25, 334.

Witham, A. C. (1957). Double outlet right ventricle: Apartial transposition complex. Amer. Heart J., 53,928.

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Double Outlet Right Ventricle - Heart · Necropsy revealed a double outlet right ventricle....

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