630 JACC Vol. 6. No.3 September 1985:630-4

Functional Aortic Valve Atresia in Transposition of the Great Arteries

ALEXANDER J. MUSTER, MD, FACC,* FAROUK S. IDRISS, MD,t

SAROJA BHARATI, MD, FACC,:j: THOMAS W. RIGGS, MD,* MAURICE LEV, MD, FACC,:j:

WALTER S. CULPEPPER III, MD, FACC,§ MILTON H. PAUL, MD, FACC*

Chicago. Illinois. Browns Mills. New Jersey and New Orleans. Louisiana

The criterion for the diagnosis of functional atresia of a patent semilunar valve is met when the pressure in a ventricle remains lower than that in the related great artery throughout systole so that no forward flow can occur. Functional pulmonary valve atresia has been well recognized in infants with normally related great arteries and massive tricuspid valve incompetence. The cardiac physiology and anatomy of an infant with transposed great arteries and functional aortic valve atresia is re­ported for the first time. The peak systolic pressure in the right ventricle was 30 mm Hg and in the aorta 64

Severe congenital malformations of the ventricular inflow tract (Ebstein's anomaly [1], valvular dysplasia [2,3], un­guarded orifice [4]) and hypoplasia of the ventricular myo­cardium (5) are usually associated with the morphologic right ventricle. When severe, these anomalies can alone or in combination compromise the pumping efficiency of the ventricle to a point where forward flow may cease altogether despite a patent ventricular outlet. This hemodynamic phe­nomenon can pe referred to as functional semilunar valvular atresia.

Functional pulmonary valve atresia has been reported in typical Ebstein's malformation of the tricuspid valve (6-8) and other forms of severe tricuspid regurgitation (7,9). Functional pulmonary valve atresia is usually limited to the neonatal period when pulmonary arteriolar resistance is el-

From the Divisions of *Cardiology (The Willis J. Potts Children's Heart Center) and tCardiothoracic Surgery, The C~ildren's Memorial Hos­pital, Chicago, Illinois; Departments of *Pediatrics and tSurgery, North­western University Medical School, Chicago, Illinois; tCongenital Heart and Conduction System Laboratory, Deborah Heart and Lung Center, Browns Mills, New Jersey and §Ochsner Clinic, New Orleans, Louisiana. This study was supported in part by the Walden W. and Jean Young Shaw Foundation, Chicago, Illinois and Grant HL 30558 from the National Heart, Lung, and Blood Institute, the National Institutes of Health, Bethesda, Maryland. Manuscript received January 4, 1985; revised manuscript re­ceived April 9, 1985, accepted April 22, 1985.

Address for reprints: Alexander J. Muster, MD, Division of Cardiol­ogy, The Children's Memorial Hospital, 2300 Children's Plaza, Chicago, Illinois 60614.

«;J 1985 by the American College of Cardiology

mm Hg. The causes for right ventricular incompetence were abnormalities of the tricuspid valve and hypoplasia of the ventricular free wall. Three other cases with sim­ilar ventricular anatomy anlf physiology but with ana­tomic atresia of the aortic valve are reviewed. The pos­sibility that under these physiologic circumstances during fetal life functional atresia develops first, and that an­atomic fusion of idle semilunar cusps develops as a sec­ondary phenomenon, is discussed.

(J Am Coli Cardiol 1985;6:630-4)

evated and when patency of the ductus arteriosus permits survival. With a gradual decrease in pulmonary arteriolar resistance and concomitant constriction of the ductus arte­riosus, a functionally compromised right ventricle can even­tually assume forward pumping and long-term survival be­comes possible even without surgical palliation.

Such favorable postnatal physiologic evolution cannot be anticipated in patients with transposed great arteries and functional aortic valve atresia because a malfunctioning right ventricle facing systemic resistance does not benefit from a postnatal drop in pulmonary vascular resistance. In such cases, wide patency of the ductus arteriosus supplying the systemic circulation from the pulmonary ventricle is man­datory for survival. Prostaglandin EI administration shortly after birth may prolong life; however, as in structural aortic valve atresia, extended survival without palliative surgery is unlikely. In this report, we present clinical, echocardio­graphic, cardiac catheterization and autopsy data of an infant with physiologically corrected transposition of the great ar­teries and functional aortic valve atresia resulting from se­vere dysfunction of the right ventricle.

Case Report This newborn infant was the product of a full-term, un­

complicated pregnancy and deli very. The birth weight was 3,900 g. Tachypnea and a heart murmur were noted shortly

0735-1097/85/$3.30

lACC Vol. 6, No.3 September 1985:630-4

after birth. Cyanosis was detected on the second day of life. The arterial partial pressure of oxygen was 35 mm Hg in room air. The chest roentgenogram revealed dextrocardia with normal visceral situs, marked cardiomegaly and normal pulmonary vascular markings. Prostaglandin EJ infusion was started and the infant was transferred to The Children's Memorial Hospital.

The pertinent physical findings on admission were mild cyanosis, prominent and equal peripheral pulses, systolic blood pressure of 66 mm Hg, hepatomegaly of 4 to 5 cm, hyperdynamic precordium, loud and single second heart sound, a grade 3-4/6 systolic murmur and a grade 1-2/6 mid-diastolic rumble at the lower right sternal border, a grade 2/6 continuous murmur at the upper left sternal border. The electrocardiogram revealed sinus rhythm, right axis deviation and large QRS complexes with left ventricular morphology over the right precordium.

The two-dimensional echocardiogram (Fig. 1) showed atricwentricular discordance, atrial septal defect, intact ven­tricular septum and an extremely thickened tricuspid valve, Transposed great arteries, aortic stenosis and mild aortic coarctation were also recognized.

Cardiac catheterization data at 41 hours of age are sum­marized in Table 1. Simultaneous pressure recording with umbilical arterial and femoral venous catheters revealed a peak systolic pressure of 30 mm Hg in the morphologic right ventricle and 75/40 mm Hg in the ascending aorta (Fig. 2). On angiography, no systolic flow from right ven­tricle into aorta occurred and massive tricuspid regurgitation into the left atrium was demonstrated (Fig. 3C). In the aortogram, valvular regurgitation into the right ventricle during systole (Fig. 3A) and diastole (Fig. 3B) was noted. The ventricular septum was intact.

Figure 1. Two-dimensional echocardiogram in apical four cham­ber view, demonstrating atrioventricular discordance, atrial septal defect and thickened tricuspid valve (*). I = inferior; L = left; LA = left atrium; LV = left ventricle; R = right; RA = right atrium; RV = right ventricle; s = atrial septum ('"flapping"); S = superior.

MUSTER ET AL. 631 FUNCTIONAL AORTIC VALVE ATRESIA IN TRANSPOSITION

Table 1. Cardiac Catheterization Data (on ventilator H02AO)

P02 (mm Hg) O2 Sat. (%) Pressure (mm Hg)

SVC 29 51 10, 16, 10* RA 50 87 11, 16, 10* LV 53 88 68/42 MPA 60 91 65/42 53t LA 102 98 II, 15, 10.5* RV 89 97 30/10 AAo 54 89 64/38 49t DAo 60 91 68/43 54t

*a wave, v wave, mean; t systolic, diastolic, mean. AAo = ascending aorta; DAo = descending aorta; FI02 = fractional concentration of in­spired oxygen in air; LA = left atrium; LV = left ventricle; MPA =

main pulmonary artery; P02 = partial pressure of oxygen; O2 Sat. oxygen saturation; RA = right atrium; RV = right ventricle; SVC =

superior vena cava.

Clinical course. The infant was maintained on prosta­glandin EJ therapy and continued to have easily palpable peripheral pulses until death, attributed to kidney and liver failure. No arrhythmia was observed during the 12 days of life.

Autopsy findings. The atria were in solitus position, pivoted to the right. The base-apex axis pointed to the right. The morphologic right atrium connected to the right-sided morphologic left ventricle by a mitral orifice, and the mor­phologic left atrium connected to the left-sided morphologic right ventricle by a tricuspid orifice. The large pulmonary trunk situated on the right and posteriorly originated from the morphologic left ventricle, and the smaller aorta situated on the left and anteriorly originated from the morphologic right ventricle. The enlarged right atrium received both venae cavae and the coronary sinus. The atrial septal defect mea-

Figure 2. Simultaneous pressure recording (after angiography) in the right ventricle (RV) and ascending aorta (AAo). The condition for functional systolic aortic valve atresia is met by the peak right ventricular pressure significantly lower than the aortic opening pressure.

mmHg -100-----------------------

-80----------------------

hAM'AJ~ (\ f\ n [l RV(\ d :2~ lTVlfVI!v

632 MUSTER ET AL. FUNCTIONAL AORTIC VALVE ATRESIA IN TRANSPOSITION

sured 2.5 cm in diameter. The morphologic left ventricle was enlarged and its wall was markedly hypertrophied. A circuitous, aneurysmally dilated ductus arteriosus was con­nected to the descending aorta. There was mild coarctation.

Figure 4. Heart specimen with opened left atrium (LA) and mor­phologic right ventricle (MRV). The arrows indicate the thinned out ventricular free wall. Note the smooth architecture of the ven­tricular inflow tract. A = absence of part of the medial tricuspid valve leaflet; ASD = atrial septal defect; TV = tricuspid valve.

JACC Vol. 6, No.3 September 1985:630-4

Figure 3. Angiography. A, Lateral aortogram in systole showing near normal-sized ascending aorta (AAo) and systolic regurgitation into the right ventricle (RV). B, Di­astolic aortic regurgitation. C, Lateral right ventricular (RV) angiogram in systole showing systolic aortic valve atresia and massive tricuspid regurgitation (arrows) into the left atrium (LA). D, Right ventricular diastole.

The left atrium was massively enlarged and had a thick wall. All pulmonary veins entered normally. The tricuspid orifice was enlarged and the valve was markedly abnormal (Fig. 4). There was no clear demarcation between leaflets, which were represented by an amorphous mass of irregular , thickened and nodular material. Papillary muscles were al­most nonexistent. Part of the anulus was devoid of valvular tissue. There were multiple attachments of valvular material to the septum. The posterior leaflet was large and slightly displaced into the morphologic right ventricle, which was markedly dilated, had an unusually thin wall and had an inflow tract devoid of trabeculations. The anterior wall was extremely thin. There was a diverticulum at the anterobasal part of the right ventricle. A shallow septal band proceeded to the base. There was no parietal band. The aortic valve (Fig. 5) consisted of three fused leaflets with low raphes and a 1.0 mm opening in the center. Both coronary ostia had a high takeoff on the posterior aspect of the aorta.

Diagnosis. Diagnosis indicated dextrocardia (mixed), physiologically corrected transposition (L-loop heart) with situs solitus of atria and ventricular inversion, mild Ebstein­like displacement of the tricuspid valve, partially unguarded tricuspid orifice, severe dysplasia of tricuspid tissue, severe hypoplasia of the right ventricular free wall with divertic­ulum formation, severe aortic valve stenosis, huge atrial septal defect, intact ventricular septum and aneurysm of patent ductus arteriosus.

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Figure S. The same specimen showing the ascending aorta (AO) and aortic valve (A V). The three valvular cusps are fused except for a central opening I mm in diameter (arrow). C = coronary orifices originating in a high position.

Discussion Incidence. Anatomic aortic atresia with normally re­

lated great arteries and intact ventricular septum is not un­common and accounts for a significant number of neonatal deaths due to a congenital heart defect. Functional aortic atresia in the same anatomic setting, however, is exceed­ingly rare. The only known report is by Macartney et al. (10), who described this defect in a neonate with severe transient myocardial dysfunction whose left ventricle was unable to generate an opening aortic pressure. Aortic atresia associated with transposition of the great arteries is ex­tremely rare either as an anatomic or functional variant. The reported cases, including our own, are presented in Ta­ble 2.

Diagnosis. The essential criterion for the diagnosis of functional aortic valve atresia in transposition of the great arteries is the demonstration of systolic pressure that is greater in the aorta than in the right ventricle in the presence of a patent aortic orifice. Our case (Case I, Table 2) meets this criterion. However, three other cases of transposition of the great arteries with anatomic aortic valve atresia also meet the pressure criterion, leading to speCUlation that the basic hemodynamics in this entity can be the same with either severe aortic valve stenosis or complete fusion of the aortic

MUSTER ET AL. 633 FUNCTIONAL AORTIC VALVE ATRESIA IN TRANSPOSITION

Table 2. Pressures and Flow Directions in Eight Reported Cases of Transposition of the Great Arteries and Either Functional or Anatomic Aortic Valve Atresia

Case 1 (present case)

Case 2 (II) Case 3 (12) Case 41

Case 5* Case 6 (13) Case 7 (13)

Case 8 (14)

Functional Atresia (L-loop) I .PDA·------------'t

LV-MPA RV ~ I"" Ao 68112 65/42 3011 0 64/38

Anatomic (? acquired) Atresia (L-loop)

I ·PDA 10 LV-MPA RV 55115 N/A 12 48/38* 80/4 60/- 40/8 40/_'

7216 70/40 N/A 70/40

Functional (postoperative) Atresia (D-loop) LV - ~-Anastomosis t

dPA-Conduit-RV,," I ~ Ao 105/10 38/16 55/8 105/50

N/A N/A

29/5 67126

Anatomic Atresia (D-loop)

35/12 7715

97/49* 84/46*

I .PDA------------~t

LV-MPA RV Ao 75/8 NI A 230/20 70150

*Femoral artery; tdescending aorta; tculpepper and Lev (unpublished data, 1984); §Muster et al. (unpublished observations, see Discussion). Ao = aorta; dPA = distal pulmonary artery; LV = left ventricle; MPA = main pulmonary artery; NI A = not available; PDA = patent ductus arteriosus; RV = right ventricle.

valve leaflets (Cases 2 to 4, Table 2). Each of these three cases had ventricular inversion (L-Ioop), severe dysfunction of the left-sided (tricuspid) inflow valve and hypoplasia of the right ventricular free wall. In contrast, in the only re­ported case (Case 8, Table 2) (14) of aortic valve atresia in a D-Ioop heart associated with intact ventricular septum and a competent tricuspid valve, the right ventricle was thick­walled and had a systolic pressure far in excess of that in the aorta. These observations lead to the hypotheses that with transposition of the great arteries and severe right ven­tricular dysfunction during fetal life, the criteria for func­tional aortic valve atresia are met and that such prenatal hemodynamics can result in a prenatal heart with either a patent but abnormal aortic valve or, more likely, with a prenatally acquired aortic valve atresia.

Pathogenesis. The possibility of prenatal fusion of idle pulmonary valve cusps was discussed by Kutsche and Van Mierop (15) in cases with hypoplastic right ventricle and intact ventricular septum. They supported their hypothesis by their findings of nearly normal morphology of the fused pulmonary valve and normal size of the pulmonary trunk. Bharati et al. (3) referred to "agglutination" of pulmonary valve cusps with normal raphes, resembling those with val­vular patency in cases with severe tricuspid regurgitation.

634 MUSTER ET AL. FUNCTIONAL AORTIC VALVE ATRESIA IN TRANSPOSITION

Postnatal fusion of functionally idle pulmonary cusps has also been reported (16) in tetralogy of Fallot with acquired infundibular atresia after surgical aortopulmonary shunts.

Postoperative functional aortic valve atresia results from the operative design of an anatomic correction for complete transposition of the great arteries proposed by Damus (17) and reported by Stansel (18) and Kaye (19). In this pro­cedure, the main pulmonary trunk is divided and its proximal end anastomosed to the ascending aorta. The original aortic relation with the right ventricle remains unaltered, yet the aortic valve remains functionally closed during systole be­cause of the higher aortic pressure while the right ventricle ejects preferentially through a valved conduit into the low resistance distal pulmonary artery. This operation was first performed successfully by Danielson et al. (13) (Cases 6 and 7, Table 2). Case 5 in Table 2 is that of a 3.8 year old girl operated on at our institution using this method. Func­tional aortic valve atresia was confirmed by the postoper­ative right ventricular angiogram shJwing systolic filling of the pulmonary arteries only and by manipulating the arterial catheter retrograde from the aorta into the right ventricle.

Implications. In a fetus with a grossly malfunctioning right ventricle caused by inflow valve incompetence and hypoplastic myocardium, partial or complete fusion of semi­lunar valve cusps may be acquired after a period of func­tional valvular atresia during early stages of fetal devel­opment, regardless of whether there is ventriculoarterial concordance or discordance. In infants born with functional pulmonary valve atresia, spontaneous improvement after birth is possible, but in infants born with functional aortic valve atresia, the transition from fetal to neonatal cardio­pulmonary physiology is fatal, just as it is in anatomic aortic valve atresia. The size of the arterial trunk and the extent of valve leaflet fusion may be an' indication whether forward flow from the ventricle ceased during earlier or later stages of fetal life.

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Ebstein's disease. Arch Pathol 1970;90:334-43.

2. Becker AE, Becker MJ, Edwards JE. Pathologic spectrum of dysplasia of the tricuspid valve. Arch Pathol 1971;91: 167-78.

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3. Bharati S, McAllister HA Jr, Chiemmongkoltip P, Lev M. Congenital pulmonary atresia with tricuspid insufficiency: morphologic study. Am J Cardiol 1977;40:70-5.

4. Kanjuh VI, Stevenson JE, Amplatz K, Edwards JE. Congenitally unguarded tricuspid orifice with coexistent pulmonary atresia. Cir­culation 1964;30:911-7.

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6. Newfeld EA, Cole RB, Paul MH. Ebstein's malformation of the tri­cuspid valve in the neonate. Functional and anatomic pulmonary out­flow tract obstruction. Am J Cardiol 1967;19:727-3l.

7. Freedom RM, Culham G, Moes F, Olley PM, Rowe RD. Differen­tiation of functional and structural pulmonary atresia: role of aortog­raphy. Am J Cardiol 1978;41:914-20.

8. Schrire V, Sutin GJ, Barnard CN. Organic and functional pulmonary atresia witlt intact ventricular septum. Am J Cardiol 1961 ;8: 100-8.

9. Barr PA, Celermajer JM, Bowdler JD, Cartmill TB. Severe congenital tricuspid incompetence in the neonate. Circulation 1974;49:962-7.

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11. Brenner JI, Bharati S, Winn WC, Lev M. Absent tricuspid valve with aortic atresia in mixed levocardia (atria situs solitus, L-Ioop). A hith­erto undescribed entity. Circulation 1978;57:836-40.

12. Deanfield JE, Anderson RH, Macartney FJ. Aortic atresia with "cor­rected transposition of the great arteries" (atrioventricular and ven­triculoarterial discordance). Br Heart J 1981 ;46:683-6.

13. Danielson GK, Tabry IF, Mair DD, Fulton RE. Great-vessel switch operation without coronary relocation for transposition of the great arteries. Mayo Clin Proc 1978;53:675-82.

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15. Kutsche LM, Van Mierop LHS. Pulmonary atresia with and without ventricular septal defect: a different etiology and pathogenesis for the atresia in the 2 types? Am J Cardiol 1983;51 :932-5.

16. Sabiston DC Jr, Cornell WP, Criley JM, Neill CA, Ross RS, Bahnson HT. The diagnosis and surgical correction of total obstruction of the right ventricle. An acquired condition developing after systemic artery­pUlmonary artery anastomosis in tetralogy of Fallo!. J Thorac Car­diovasc Surg 1964;48:577-87.

17. Damus PS. Letter to the editor. Ann Thorac Surg 1975;20:724-5.

18. Stansel HC Jr. A new operation for d-Ioop transposition of the great vessels. Ann Thorac Surg 1975; 19:565-7.

19. Kaye MP. Anatomic correction of transposition of the great arteries. Mayo Clin Proc 1975;50:638-40.