Markedly Dilated Right Heart 17 Years After Initial Treatment Repaired by Total Right Ventricular Exclusion and Total Cavopulmonary Connection
The total right ventricular (RV) exclusion procedure for isolated congestive RV failure, in which most of the dilated right atrium (RA) and RV wall is resected, was first reported by Sano et al in 2002.1 This procedure improves the cardiac index2 and suppresses supraventricular/ventricular tachyarrhythmia. Using this procedure with an extracardiac conduit, we successfully treated severe heart failure characterized by a markedly dilated right heart lacking tricuspid leaflets and by recurrent tachyarrhythmia, 17 years after the patient had undergone initial definitive intracardiac repair including RV outflow tract plasty.
A 22-year-old woman presented with general fatigue, dyspnea, palpitations, and loss of appetite of 6 months’ duration caused by low cardiac output. She was admitted to the University of Tokyo Hospital to undergo surgery to improve her low cardiac output. She was cyanotic at birth after an uneventful pregnancy and caesarian delivery. Cardiac catheterization performed when she was 47 days old revealed pulmonary atresia with atrial septal defect and patent ductus arteriosus. A Blalock-Taussig anastomosis was established. Subsequently, she was diagnosed with absent tricuspid valve, pulmonary atresia, and atrial septal defect. These were definitively treated surgically in 1990 when the patient was 5 years old via RV outflow tract plasty and atrial septal defect closure. Intraoperative findings included weak RV contraction and an anterior RV wall almost totally lacking myocardium. Five years after the operation, she suffered from ventricular tachycardia originating from the RV wall, which was treated by electrical cardioversion and subsequent administration of oral antiarrhythmic medication. Six months before admission, dyspnea and palpitations were noted, and further examination revealed incisional atrial flutter.
On admission, the patient was classified as being in New York Heart Association functional class IV. Her blood pressure was 88/56 mm Hg, and her heart rhythm was atrial flutter or fibrillation. The rhythm became transiently junctional, and epsilon waves were present in the right precordial leads (Figure 1). Chest x-ray showed an enlarged cardiac silhouette forming a double contour on the right cardiac border (Figure 2). Echocardiography revealed a remnant tricuspid valve as a small protrusion. The RV wall was thin; RV contractility was completely absent. The interventricular septum was dyskinetic with a high echo level and had been infiltrated by cystic lesions (Figure 3, Movie I). Computed tomography and its volume-rendered 3-dimensional images of the heart (Figure 4, Movie II) showed a markedly dilated RA and RV. Cardiac catheterization revealed no pressure gradient through the vena cava to the pulmonary artery, demonstrating establishment of the Fontan circulation. The pulmonary vascular resistance was 2.5 U · m2. Advancing low-output syndrome with arrhythmia refractory to medical therapy, consistent with a failing Fontan, prompted our decision to perform the total RV exclusion procedure with total cavopulmonary connection (TCPC).
The total RV exclusion and TCPC conversion procedure were performed with atrioventricular nodal cryoablation, extracardiac pacemaker implantation, and atrial septal defect creation. The unguarded tricuspid orifice was closed with a fenestrated patch. Three-dimensional images of the heart were obtained (Figure 5, Movie III). Echocardiography revealed a decompressed left ventricle (Figure 6, Movie IV). The left ventricular ejection fraction (obtained by quantitative gated single-photon-emission computed tomography) increased from 45% to 51%. Cardiac catheterization revealed an increase in the cardiac index from 1.20 to 2.38 L · min−1 · m−2. The patient is in functional class II and remains free of arrhythmia 14 months after the operation.
The differential diagnosis of markedly dilated right heart with severe tricuspid insufficiency includes Ebstein’s anomaly, arrhythmogenic RV cardiomyopathy (ARVC), and Uhl’s anomaly. Another characteristic of this case is the congenital absence of tricuspid leaflets, which is consistent with the congenitally unguarded tricuspid orifice named by Kanjuh et al.3 The absence of apical displacement of the tricuspid septal leaflet rules out Ebstein’s anomaly. An intact tricuspid valve and normal LV wall should be observed in Uhl’s anomaly, which is also ruled out in this case. Histopathological examination demonstrated prominent fibrous and patchy fatty infiltration of RV myocardium. Fibrofatty infiltration, epsilon waves, late potentials on the signal-averaged ECG (data not shown), and ventricular tachycardia of RV origin fulfill the diagnostic criteria of ARVC,4 whereas slowly progressive arrhythmic episodes and RV dysfunction discourage us from making a definite diagnosis of ARVC at this point. The most likely diagnosis in this case is failing Fontan circulation occurring 17 years after RV outflow tract plasty for congenitally unguarded tricuspid orifice with pulmonary atresia, probably overlapping with ARVC of unknown onset.
To date, 8 cases of the total RV exclusion procedure for Ebstein’s anomaly and ARVC have been reported.1,2 We are the first group to apply this procedure to a patient with failing Fontan circulation with markedly dilated RA and RV and a history of congenitally unguarded tricuspid orifice. In this case, similar to a failing Fontan resulting from a failing atriopulmonary connection, energy losses in the circuit were increased by the dilated RA and RV, as well as by the compliance of their walls and compression of pulmonary veins. Total RV exclusion abolished these energy losses and removed arrhythmogenic tissue, and subsequently, the cardiac output and the functional status improved markedly. Volume-rendered 3-dimensional imaging using computed tomography was a helpful tool for comprehensive understanding of cardiac anatomy during the preoperative evaluation. Our report suggests that the total RV exclusion procedure with TCPC can be a therapeutic option for failing Fontan circulation with severely low output caused by an impaired and dilated right heart. The procedure concomitantly eradicates atrial and ventricular arrhythmias. Additional investigation of clinical outcomes after the total RV exclusion procedure with TCPC are anticipated.
The online-only Data Supplement can be found with this article at http://circ.ahajournals.org/cgi/content/full/118/9/e133/DC1.
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Kanjuh VI, Stevenson JE, Amplatz K, Edwards JE. Congenitally unguarded tricuspid orifice with coexistent pulmonary atresia. Circulation. 1964; 30: 911–917.
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