Aneurysm of the atrial septum in tricuspid atresia

Aneurysm of the Atrial Septum in Tricuspid Atresia Diagnosis During Life and Therapy

ROBERT M. FREEDOM, MD, FACC RICHARD D. ROWE, MD Toronto, Ontario, Canada

Massive aneurysmal dilatation of the foramen ovale was diagnosed angiocardiographically in a patient with tricuspid atresia. The angiographic findings are distinct for this condition, and the pathogenesis appears to be related to a restrictive atrial communication in the patient with obligatory right to left shunting at atrial level. The anatomic potential for atrial restriction in the patient with tricuspid or pulmonary atresia, intact ventricular septum and diminutive right ventricle necessitates balloon atrial septostomy at the initial diagnostic cardiac catheterization. in the patient with aneurysmal dilatation of the foramen ovale, satisfactory decompression may be achieved by Blalock-Hanlon atrial septectomy, open atrial septectomy or, possibly, balloon septostomy.

A restrictive atria1 communication poses a considerable hemodynamic burden to the patient with tricuspid atresia whose survival depends on an obligatory right to left shunt at this level. The pathologic findings of aneurysmal dilatation or outpouching of the atria1 septum in the region of the fossa ovalis have been described by Levi in a patient with tricuspid atresia and restrictive atria1 communication who had a huge aneurysm of this type bulging into the left atrium and potentially obstructing the mitral valve orifice. We present herein the distinct angiocardiographic findings in a patient with tricuspid atresia and an aneurysm of the atria1 septum and with a discussion of modes of therapy. Case Report A 2 day old male infant was referred to this institution for evaluation of cyanotic congenital heart disease.Physical examination revealed a mildly cyanosed, tachypneic infant, with a heart rate of 160 beats/min and a respiratory rate of 60lmin. Cardiac findings included a mild left ventricular impulse, a grade 2/6 systolic ejection murmur along the left sternal border and a grade 3/6 continuous ductal murmur over the pulmonary area. The second heart sound was single. All pulses were weak. The liver was palpable 3 cm below the right costal margin. Chest radiography revealed cardiomegaly with a prominent right atrium and diminished pulmonary vascularity. There was visceral situs solitus (Fig. 1). The electrocardiogram showed a leftward superior axis with evidence of left

From the Division of Paediatric Cardiology, Department of Paediatrics, The Hospital for Sick Children, and The Faculty of Medicine, The University of Toronto, Toronto, Ontario. Canada. Manuscript received May 1, 1975; revised manuscript received July 21, 1975, accepted July 23. 1975. Address for reprints: Robert M. Freedom, MD, Department of Cardiology, the Hospital for Sick Children, 555 University Ave., Toronto, Canada M5G 1X8.

ventricular hypertrophy, biatrial enlargement and a low atria1 or coronary sinus pacemaker (Fig. 2). Cardiac catheterization was performed shortly after admission. The hemodynamic findings are summarized in Table I. The catheter course suggested tricuspid atresia. The left ventriculogram demonstrated a large left ventricle, high ventricular septal defect, hypoplastic right ventricular outlet chamber, moderate pulmonary stenosis and a,patent ductus arteriosus. The pulmonary arteries were mildly hypoplastic. The great vessels were normally related. A cineangiocardiogram performed at the junction of thknferior uena caua and right atrium revealed a dilated right atrium with very faint opacification of the left ventricle and ascending aorta (Fig. 3). During right atrial systole, the aneurysm bulged massively into the left atrium, almost reaching the left heart border. In right atria1 diastole, the aneurysmal dilatation decreased in size. At the conclusion of the procedure a balloon septostomy was attempted but was

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not considered successful. The final anatomic diagnoses were tricuspid atresia (type Ib), pulmonary stenosis, hypoplastic right ventricle, patent ductus arteriosus and aneurysmal dilatation of the atria1septum. The systemic hypotension was attributed in part to severe restriction of obligatory atrial flow. A Blalock-Ha&on atria1 septectomy, a Waterston shunt, and ligation of the ductus arteriosuswere accomplished at age 3 days. The infant tolerated the procedure well; his cyanosis lessened and heart size decreased. Sepsis due to a gram negative organism developed and he died 3 days postoperatively. A necropsy examination was not performed. Discussion Malformations of the septum primum component of the interatrial septum have been characterized by

TABLE

I

Cardiac Catheterization

Data

oxygen Saturation* (%)

Site Inferior vena cava Superior vena cava Right atrium Left atrium Left ventricle Aorta Pulmonary artery

Pressure (mm Hg)

60

ii

all;v5;m5 all;v5;m5 42/l 1 42120

72

:: Not entered

“All saturation data were obtained 100 percent oxygen. a ==a wave; m = mean; v = v wave.

while the infant was breathing

I

R”3

FIGURE

1 (top).

FIGURE

2 (right).

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partial or total absence, fenestration, neoplasia, premature closure and relative malposition.2-4 In certain congenital cardiac anomalies right to left shunting at the atria1 level is obligatory. In patients with tricuspid atresia, the interatrial communication represents the only exit from the blind right atrium. Likewise, although the right atrium in the patient with pulmonary atresia and intact ventricular septum may decompress through the sinusoidal-coronary arterial communications, an atria1 communication is almost invariably present. The clinical features of atria1 restriction in the patient with tricuspid atresia have previously been described.” Anatomically, the restriction is manifested by an obliquely patent foramen ovale or several fenestrations in the septum primum with the septum primum bulging into the left atrium. Massive aneurysmal dilatation of the septum primum as manifested in our case is undoubtedly rare. This grotesque dilatation is probably evidence of severe restriction but might represent an associated anomaly. Thompson et aL6 have described an adult with a filling defect in the right atrium, thought to be caused by a tumor, probably a myxoma. At surgery the defect was found to be due to a redundant and fibrous interatrial septum. Other examples of aneurysmal sacculation of the atria1 appendage in patients without congenital heart disease have been described.7-11 In addition, Rowe et a1.12 have described an infant with recurrent tachyarrhythmias and multiple saccular aneurvsms of the right atrium. It is remotely possible that - these two conditYons are related. Decompression of the restrictive atria1 communi-’ cation can be achieved with balloon atria1 septostomy,

II

R”4

aVR

III

RV5

aVL

aVF

RV(j

Chest radiograph. Electrocardiogram

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FIGURE 3. Cineangiocardiograms. Left, during right atrial systole. With the catheter in the inferior vena cava (VC), contrast material opacifies the vena cava, hepatic veins and right atrium @A). The massive aneurysmal dilatation of the foramen ovale (ans) is well-visualized during right atrial systole. Opacification of the left atrium (LA) is noted. The sequence of opacification is typical for tricuspid atresia. Right, during right atrial diastole and filling, the aneurysmally dilated foramen ovale is not evident. The left heart chambers are never densely opacified, probably because of severe atrial restriction. Between atrial systole and diastole, a “ping-pong” ball effect is produced by the phasic aneurysmal dilatation of the foramen ovale.

the Blalock-Hanlon atria1 septectomy or open atria1 septectomy using hypothermia or inflow occlusion. The incidence of true secundum atria1 defects in patients with tricuspid atresia or pulmonary atresia and intact septum is not known. Because atria1 restriction can mitigate successful palliation by systemic to pulmonary artery anastomoses for hypoxia, a balloon atria1 septostomy should probably be performed at the initial cardiac catheterization. Furthermore, since Fontan and Baudet13 have achieved right ventricular bypass in the patient with tricuspid atresia, every effort should be made to allow these patients to reach the age when conduit surgery can be performed.

Intermittent obstruction of the mitral valve by the aneurysmal dilatation of the atria1 septum is possible, and this diagnosis should be considered when findings consistent with intermittent mitral stenosis develop in a patient with tricuspid atresia. In this regard, the similarity of the findings to those of a pedunculated left atria1 myxoma is obvious. Finally, although we have described aneurysmal dilatation of the interatrial septum in a patient with tricuspid atresia, atria1 restriction is similarly common in the patient with mitral atresia. In this situation, the valve of the foramen ovale may herniate into the right atrium and aneurysmal dilatation may occur.

References 1. Lev M: Autopsy Diagnosis of Congenitally Malformed Hearts. Springfield, Ill, Charles C Thomas, 1953, p 22 2. Edwards JE, Carey LS, Neufeld HN, et al: Congenital Heart Disease. Correlation of Pathologic Anatomy and Angiocardiography, Vol I. Philadelphia and London, WB Saunders, 1965. o 353 3. Hudson REB: Cardiovascular Pathology, Vol 2. Baltimore, Williams &Wilkins, 1965, p 1565-1570, 1803-1807 4. Fine G: Primary tumOrs of the pericardium and iheart. In. The Heart, (Edwards JE, Lev M, Abell MR. ed). Baltimore, Williams & Wilkins, 1974, p 196-198 5. Taussig HB: Congenital Malformations of The Heart, Vol II, Specific Malformations. Cambridge, Mass, Commonwealth Fund, 1960, p 85-87 6. Thompson JI, Phillips LA, Melrnon KL: Pseudotumor of right atrium. Report of a case and review of its etiology. Ann Intern Med 64: 665-667, 1966 7. Morrow GA, Behrendl MD: Congenital aneurysm (diverticulum)

6. 9. 10. 11. 12.

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of the right atrium. Clinical manifestations and results of operative treatment. Circulation 38:124-128, 1968 Williams WG: Dilatation of the left atrial appendage. Br Heart J 25~637-643. 1963 Pins RM, Potts WJ: Congenital diverticulum of the left atrium. Arch Surg 841334-336, 1962 Canavan MM: Two hearts with anomalies in the interauricular septum. J Tech Methods 20:68-72, 1940 Lang FJ, PosseIt A: Aneut-ysmatische Vorwolbung der Fossa ovalis in den linken Vorhof. Wien Med Wschr 84:392-396, 1934 Varghese PJ, Simon AL, Rosenqulst GC, et al: Multiple saccular congenital aneurysms of the atria causing persistent atrial tachycardia in an infant. Report of a case successfully treated by surgery. Pediatrics 441429-433, 1969 Fontan F, Baudet E: Surgical repair of tricuspid atresia. Thorax 266:240-248, 1971

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