Acyanotic “Taussig-Bing heart” and its surgical aspects

Aim: To report a case of acyanotic Taussig-Bing heart, anatomically consistent with L-transposition and rheumatic Left AV valve regurgitation associated with complete AV block in a male child. Introduction: Taussig-Bing heart is one of the conotruncal malformation, characterized by double-outlet right ventricle (DORV) and a subpulmonary VSD. Embryologically, abnormal cardiac looping and malalignment of conotruncal septum determines its complexity and great artery relationships. Case Report: A 14-year-old acyanotic boy presented with severe left-sided AV valve regurgitation and bradycardia. ECG revealed left sided morphologic right ventricular hypertrophy (RVH) as evidenced by a loss of septal Q waves in left precordial leads suggesting ventricular inversion. X-ray chest revealed a straight upper right cardiac border due to loss of normal relationship of great vessels and cardiomegaly due to both left atrial and morphologic right ventricular enlargement suggesting a left-sided regurgitant lesion. Echocardiography revealed the ventricular inversion, primary origin of both L-transposed great arteries from the left-sided morphologic right ventricle suggesting a ‘double-outlet morphologic right ventricle’ with ‘double discordance’ and a subpulmonary VSD of Taussig-Bing type. The left-sided morphologic tricuspid valve is severely regurgitant due to rheumatic process resulting in heart failure which was improved with anti-failure measures and penicillin prophylaxis. Conclusion: The presence of left-sided regurgitation associated with bradycardia is a suspicion of ‘double discordance’ and ‘double switch’ procedure remains the mainstay of its surgical correction. Left AV valve replacement with intraventricular repair is preferred in this child since the malformation is consistent with Taussing-Bing type of DORV with L-transposition.