double outlet left ventricle - heart

British Heart Journal, I974, 36, 554-558.

Double outlet left ventricle

Robert Anderson, Robert Galbraith, Ronald Gibson, and Graham MillerFrom the Department of Cardiology, Brompton Hospital, Fulham Road, London

A case, the sixth, ofdouble outlet left ventricle is reported, the diagnosis being made by cardiac catheterization andangiocardiography. Though the existence of such a malformation has been questioned on embryologicalgrounds,double outlet left ventricle must now be regarded as a recognized cardiac anomaly. The embryologicalsignificance of this case is discussed and it is suggested that the malformation is easily explained by the hypo-thesis of differential conal absorption.

Although the existence of double outlet leftventricle has been doubted on embryologicalgrounds (Grant, I962; Van Mierop and Wiggles-worth, i963), 5 cases have recently been reported(Sakakibara et al., I967; Paul et al., I970; Kerret al., I97I; Pacifico et al., I972) and it is now arecognized congenital cardiac malformation. In thispaper, a further case of double outlet left ventricleis described and some of the diagnostic problemsand possible surgical approaches relating to this rarecondition are discussed as are the embryologicalevents which may produce the anomaly.

Case reportThe patient was a 5-year-old Iranian boy with nofamily history of heart disease. There was no knownexposure to x-rays, potentially teratogenic drugs, orviruses during pregnancy, and his birth was normalat term. Persistent central cyanosis appeared duringthe first IO days of life, and, latterly, mild effortdyspnoea had been noted. He had not been greatlylimited by these symptoms, and there had been no feed-ing difficulties, squatting episodes, or tendency to re-current respiratory infections.On examination, he was small (height and weight on

tenth centile) with pronounced clubbing and centralcyanosis. Peripheral arterial and jugular venous pulseswere normal, and oedema was not present. The cardiacimpulse was normal. On auscultation, there was a grade3/6 ejection systolic murmur maximal at the left secondintercostal space, the second sound was single, and noejection click was audible. No abnormality was foundelsewhere. The electrocardiogram showed sinus rhythm,a mean frontal QRS axis of -I500, and a dominant I5mm R wave in V4R and Vi (Fig. I). The plain chestx-ray revealed only slight cardiac enlargement and thepulmonary vasculature appeared normal. The haemo-globin was I7-I g/ioo ml. The differential diagnosis wasReceived 3 December I973.

tetralogy of Fallot, double outlet right ventricle withpulmonary stenosis and endocardial cushion defectwith pulmonary stenosis.At cardiac catheterization, the right side of the heart

was studied from the right axillary vein and the left sidefrom the right saphenous vein via the foramen ovalewhich was patent. The catheter crossed a ventricularseptal defect to enter the aorta; the pulmonary arterywas entered from the left ventricle using a Swan-Ganzballoon-tipped flow-directed catheter. The pressures andoxygen saturations obtained are shown in the Table. A

TABLE Cardiac catheterization findings

Site Pressure Oxygen(mmHg) saturation (%)*

Right atrium Mean 3 6iRight ventricle 95/-6 65Pulmonary artery I2/9 mean ii 8iLeft atrium mean 7 99Left ventricle 95/2-6 99Aorta 95/75 82

* Measured by reflection oximetry.Qp/Qs =4-2/3-9 1./min per M.2

large fall in oxygen saturation was apparent between leftventricle and aorta, and a similarly large increase be-tween right ventricle and pulmonary artery, so that theoxygen saturation in the pulmonary artery was almostequal to that in the aorta. Right and left ventricularpressures were identical. There was valvar pulmonarystenosis (systolic gradient of 83 mmHg), but calculatedpulmonary blood flow was slightly greater than systemicblood flow.

Serial angiocardiograms were performed with injec-tions of contrast medium in the aorta, right ventricle,and left atrium. The right ventriculogram (Fig. 2) re-vealed that the anterior, morphological right ven-tricular cavity ended blindly superiorly and appeared to

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Double outlet left ventricle 555

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FIG. i Electrocardiogram.

FIG. 2 Right ventricular injection, lateral pro-

jection. There is opacification of the left ventricle

via a ventricular septal defect. The pulmonary artery

fills.from the F.left ventricle and pulmonary stenosis is

demnonstrated.

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556 Anderson, Galbraith, Gibson, and Miller

FIG. 3 Left atrial injection. Lateral projection.There is opacification of aorta (and pulmonary artery)with no opacification of right ventricle. There isaortic-mitral valvar continuity.

lack an infundibulum. All the contrast passed posteriorlythrough a large ventricular septal defect into a morpho-logical left ventricle, and thence into both aorta andpulmonary artery. A subpulmonary conus was visible,the pulmonary valve was small and slightly thickened,and the pulmonary vessels were all somewhat reducedin size. The left atrial injection (Fig. 3) confirmed thatboth pulmonary artery and aorta arose from the mor-phological left ventricle and mitral-aortic continuitywas clearly demonstrated. The pulmonary valve lay tothe left, posteriorly and superiorly in relation to theaortic valve. No contrast passed into the right atrium or

right ventricle during this angiogram. An aortogramshowed a left-sided aortic arch with some dilatation ofthe ascending aorta. There was slight opacification ofthe pulmonary arterial tree via moderately enlargedbronchial arteries, but no evidence of any other com-

munication between aorta and pulmonary artery. Thefinal catheter diagnosis was double outlet left ventriclewith a ventricular septal defect, valvar pulmonarystenosis, and a persistent foramen ovale.A palliative aorta to right pulmonary artery shunt was

performed by Mr. M. Paneth. At operation, the externalappearances of the heart were found to be compatiblewith the catheter diagnosis. Postoperative progress was

uneventful and the patient was discharged with a viewto performing total correction at some future time.

Discussion

Double outlet left ventricle may be defined as theorigin of both pulmonary artery and aorta from themorphological left ventricle. Malformations wherethe great arteries arise from the morphological rightventricle, which is left-sided by virtue of associatedventricular inversion, are best regarded as a variantof double-outlet right ventricle (Fragoyannis andKardalinos, I962; Ruttenburg et al., I964; Kiseret al., I968). The patient presented in this paperthus has true double outlet left ventricle as definedabove.The existing case reports of double outlet left

ventricle, though few in number (Sakakibara et al.,I967; Paul et al., I970; Kerr et al., I97I; Pacificoet al., 1972), clearly demonstrate that wide variationin anatomy is possible. The major differences arewith respect to the presence or absence of a ventric-ular septal defect and of pulmonary stenosis, thedistribution of conal musculature, and the inter-relations of the great arteries. Thus, in the case ofdouble outlet left ventricle reported by Sakakibaraet al. (I967), there was no pulmonary stenosis, therewas a large subpulmonary conal septal defect, andthe aorta and pulmonary artery were normally re-lated. Paul et al. (I970) described a case of doubleoutlet left ventricle with no pulmonary stenosis, butan intact ventricular septum. Conal tissue was bi-laterally hypoplastic and the semilunar valves layside by side equally posteriorly, the aortic valve tothe right and the pulmonary valve to the left atapproximately the same height. In contrast, in thepatient of Kerr et al. (197I) double outlet left ven-tricle was associated with a subpulmonary ventric-ular septal defect and severe pulmonary stenosis,though the relative positions of aorta and pulmonaryartery were similar to those in the previous case(Paul et al., I970). These three examples of doubleoutlet left ventricle demonstrate quite distinctanatomy, and form the basis of a classification ofdouble outlet left ventricle suggested recently byR. Van Praagh (I973, personal communication).The lesions in our case appear to be very similarto those found by Kerr et al. (197I), except thatthe pulmonary valve was slightly posterior andsuperior to the aortic valve.There is corresponding diversity in the clinical

features. In the cases of Sakakibara et al. (I967) andPaul et al. (I970), in whom pulmonary stenosis anddefinite cyanosis were absent, the diagnoses wereventricular septal defect with pulmonary hyper-tension and tricuspid atresia with d-transpositionrespectively. In the patient of Kerr et al. (I971)where severe pulmonary stenosis and pronouncedcyanosis and clubbing were present, the initial diag-



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nosis was tetralogy of Failot. The correct diagnosiswas not appreciated at cardiac catheterization in twoof the reported cases (Sakakibara et al., I967; Kerret al., I97I) and only at repeat catheterization inanother (Paul et al., I970). Commenting on thedifficulty of diagnosis, Kerr et al. (197I) point outthat the condition may be missed if left-sided injec-tions of contrast medium are not made. Howeverthe origin of the pulmonary artery from the leftventricle was clearly visible during the right ven-triculogram in our patient, and was seen in retro-spect in the case of Kerr et al. (I97I).While left-sided injections may not be performed

routinely in patients suspected of having tetralogyof Fallot, it is noteworthy that in our patient and inthose reported cases for whom figures are available(Sakakibara et al., I967; Paul et al., 1970), oxygensaturations in the aorta and pulmonary artery werealmost identical. Such findings are incompatiblewith a diagnosis of tetralogy of Fallot and shouldindicate the true diagnosis to the operator and alerthim to the need for a left-sided injection of contrastmedium.The different haemodynamic abnormalities in

these cases have also resulted in different surgicalapproaches. In the acyanotic patients (Paul et al.,I970; Kerr et al., I97I) the problem was one ofleft-to-right shunting, since both the pulmonaryartery and aorta were exposed to left ventricularpressure while pulmonary vascular resistance hadnot yet risen above systemic. Palliative pulmonaryartery banding was therefore performed in Paul'spatient (Paul et al., I970), while in Sakakibara'scase (Sakakibara et al., I967) total correction wasachieved, since intraventricular diversion of bloodfrom the right ventricle to the pulmonary arterywas readily accomplished using a patch to repairthe conal septal defect. Conversely, in our patientand in that reported by Kerr et al. (I97I) withsevere pulmonary stenosis and pronounced cyanosis,palliation was achieved by anastomosis between thepulmonary artery and aorta. Total correction waslater performed in the latter patient after two shuntshad failed to function, by creation of an artificialtunnel from right ventricle to pulmonary artery,roofed anteriorly with a free pericardial graft (Kerret al., I97I).

Alternatively, total correction may be achievedwith an extracardiac conduit from the right ventricleto the pulmonary artery as described recently intwo further patients by Pacifico et al. (I972). Whilepalliation by means of either pulmonary arterybanding or an aorto-pulmonary anastomosis ispossible, the results of total correction in doubleoutlet left ventricle appear particularly encourag-ing. All four reported patients in whom this has

been carried out (Sakakibara et al., I967; Kerret al., I971; Pacifico et al., I962) were alive andwell at 3 months, i year, 32 years, and 6 years.

EmbryologyWhen distinguished authorities expressed theopinion that double outlet left ventricle was anembryological impossibility (Grant, I962; VanMierop and Wigglesworth, I963), it was generallyheld that transposition of the great arteries was theresult of normally spiral bulbar ridges fusing instraight fashion (de la Cruz and da Rocha, I956).Using the same criteria, Van Mierop and Wiggles-worth (I963) also stated that only the classicallycomplete and corrected forms of transpositionexisted. Since that time the careful studies of VanPraagh and Van Praagh, I966; Van Praagh, I973)have shown that many forms of transposition existwhich cannot be explained on the 'straight septum'hypothesis. For this reason, Van Praagh and VanPraagh (I966) propounded their concept of differ-ential conal growth. This hypothesis was also notideal, since at no stage of normal embryonic growthis the pulmonary artery ever above the primitiveventricle, an essential premise of Van Praagh's con-cept. This fact has been elegantly demonstrated bythe study of Goor, Dische, and Lillehei (I972) andendorsed independently by Anderson and assoc-iates (Anderson, Wilkinson, and Arnold, I974;Anderson et al., 1973). As Goor has pointed out,these studies are not original since previous studiesare extant in the German literature; however theyclearly show that the aorta is taken above the leftventricle by a process of differential conal absorp-tion. Furthermore, an additional essential part ofnormal growth is that bulbar rotation must occur,so that the presumptive aortic conus is carriedposteriorly to the presumptive pulmonary artery.The vital part of Goor's work shows that if thisrotation does not occur then the aorta and pul-monary artery would be situated in the same frontalplane, with the aorta to the right. This is the preciseposition of the great arteries in most cases of doubleoutlet right ventricle, where the bilateral conus in-dicates the absence of conal absorption. In anequally elegant paper, Goor and Edwards (I973)have shown that examination of pathological speci-mens provides evidence to show a spectrum ofabnormalities between double outlet right ventricleand complete transposition depending upon thedegree of absorption of the subpulmonary conus.This investigation has also been endorsed inde-pendently by Anderson and associates (Andersonand Ashley, 1973). In complete transposition there-fore, the ventricular septal defect is not a typical



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558 Anderson, Galbraith, Gibson, and Miller

membranous septal defect, but represents the gapbetween the ventricular and conal septa. If this gapis large it is also possible for partial absorption of theaortic conus to occur through it. This producesposterior displacement of the aorta, and the so-called 'posterior transposition with mitral-aorticfibrous continuity' (Van Praagh et al., 197I).Clearly if this absorptive process continued, thenboth conuses would be absorbed above the primi-tive ventricle, producing double outlet left ventricle.Since there is usually a pulmonary conus in posteriortransposition, it would be expected that in doubleoutlet left ventricle, while the aortic conus would bedeficient, the pulmonary conus could be eitherabsent or present. This supposition is borne out bythe published cases. The one case that is difficult toexplain is that with an intact septum, but then casesof double outlet right ventricle with intact septumare equally difficult to explain (Oppenheimer-Dekker and Gittenberger-De Groot, I97I). How-ever, in our experience (Anderson et al., 1973 andunpublished data), microscopical evidence of abulboventricular foramen is always present, and it islikely that the intact septum is purely ventricular inorigin. Thus the previous cases together with ourown attest to the existence of double outlet leftventricle, and we believe that the anomaly is easilyexplained by the differential conal absorptionhypothesis.

ReferencesAnderson, R. H., and Ashley, G. T. (I973). Development of

the cardiovascular system. In Scientific Basis of Paediatrics,p. I82. Ed. by J. Davies and J. Dobbing. Heinemann,London.

Anderson, R. H., Thapar, M. K., Arnold, R., and Jones, R. S.(I973). Study of conducting tissue in a case of ven-tricular pre-excitation. British Heart_Journal, 35, 566.

Anderson, R. H., Wilkinson, J. L., Arnold, R., and Lubkie-wicz, K. (I974). Morphogenesis of bulboventricular mal-formations. I: Consideration of embryogenesis in the nor-mal heart. British Heart Journal, 36, 242.

De la Cruz, M. V., and da Rocha, J. P. (I956). An ontogenetictheory for the explanation of congenital malformationsinvolving the truncus and conus. American Heart Journal,51, 782.

Fragoyannis, S., and Kardalinos, A. (I962). Transposition ofthe great vessels, both arising from the left ventricle (juxta-position of pulmonary artery). American Journal of Car-diology, Io, 6oi.

Goor, D. A., Dische, R., and Lillehei, C. W. (I972). The cono-truncus. Its normal inversion and conus absorption.Circulation, 46, 375.

Goor, D. A., and Edwards, J. E. (1973). The spectrum oftransposition of the great arteries, with specific referenceto development anatomy of the conus. Circulation, 48, 406.

Grant, R. P. (I962). The morphogenesis of transposition ofthe great vessels. Circulation, 26, 8I9.

Kerr, A. R., Barcia, A., Bargeron, L. M., and Kirklin, J. W.(I97I). Double-outlet left ventricle with ventricular septaldefect and pulmonary stenosis: report of surgical repair.American Heart Journal, Si, 688.

Kiser, J. C., Ongley, P. A., Kirklin, J. W., Clarkson, P. M.,and McGoon, D. C. (I968). Surgical treatment of dextro-cardia with inversion of ventricles and double-outlet rightventricle. Journal of Thoracic and Cardiovascular Surgery,55, 6.

Oppenheimer-Dekker, A., and Gittenberger-De Groot, A.(I97I). Double outlet right ventricle without ventricularseptal defect. A challenge to the embryologist? Micro-scopic investigation. Zeitschrift fur Anatomie und Entwick-lungsgeschichte, 134, 243.

Pacifico, A. D., Bargeron, L. M., Kirklin, J. W., and Barcia,A. (I972). Surgical treatment ofdouble-outlet left ventricle.Circulation, 45 and 46, Suppl. 2, 35.

Paul, M. H., Muster, A. J., Sinha, S. N., Cole, R. B., andVan Praagh, R. (I970).Double-outlet left ventricle with anintact ventricular septum: clinical and autopsy diagnosisand developmental implications. Circulation, 41, I29.

Ruttenburg, H. D., Anderson, R. C., Elliott, L. P., andEdwards, J. E. (I964). Origin of both great vessels fromthe arterial ventricle: a complex with ventricular inversion.British Heart Journal, 26, 63I.

Sakakibara, S., Takao, A., Arai, T., Hashimoto, A., and Nogi,M. (I967). Both great vessels arising from the left ventricle.Bulletin of the Heart Institute ofJapan, p. 66.

Van Mierop, L. H. S., and Wigglesworth, F. W. (I963).Pathogenesis of transposition complexes: II. Anomaliesdue to faulty transfer of the posterior great artery. Ameri-can Journal of Cardiology, I2, 226.

Van Praagh, R. (I973). Conotruncal malformations. In HeartDisease in Infancy, pp. I4I-I88. Ed. by B. G. Barratt-Boyes, J. M. Neutze, and E. A. Harris. Churchill Living-stone, London.

Van Praagh, R., Perez-Trevino, C., Lopez-Cuellar, M.,Baker, F. W., Zuberbuhler, J. R., Quero, M., Perez, V. M.,Moreno, F., and Van Praagh, S. (I97I). Transposition ofthe great arteries with posterior aorta, anterior pulmonaryartery, sub-pulmonary conus and fibrous continuity be-tween the aortic and atrioventricular valves. AmericanJournal of Cardiology, a8, 621.

Van Praagh, R., and Van Praagh, S. (1966). Isolated ventric-ular inversion. A consideration of the morphogenesis,definition and diagnosis of non-transposed and transposedgreat arteries. American Journal of Cardiology, 17, 395.

Requests for reprints to Dr. Graham Miller, BromptonHospital, Fulham Road, London SW3 6HP.



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