Interventricular dyssynchrony due to unilateral atrioventricular conduction block in a patient with right atrial isomerism and twin atrioventricular nodes

Abstract

We often experience heterotaxy syndrome and twin atrioventricular (AV) nodes. Their ventricular morphologies are complicated and heterogeneous. Moreover, the associated conduction system anatomy has not yet been fully elucidated. On the other hand, experimental AV node modification has been conducted for AV reciprocating tachycardia involving 2 distinct AV nodes 1 Wu M.H. Lin J.L. Wang J.K. Chiu I.S. Young M.L. Electrophysiological properties of dual atrioventricular nodes in patients with right atrial isomerism. Br Heart J. 1995; 74: 553-555 Crossref PubMed Scopus (21) Google Scholar , 2 Wu M.H. Wang J.K. Lin J.L. et al. Supraventricular tachycardia in patients with right atrial isomerism. J Am Coll Cardiol. 1998; 32: 773-779 Abstract Full Text Full Text PDF PubMed Scopus (76) Google Scholar , 3 Bae E.J. Noh C.I. Choi J.Y. et al. Twin AV node and indued supraventricular tachycardia in Fontan patients. Pacing Clin Electrophysiol. 2005; 28: 126-134 Crossref PubMed Scopus (48) Google Scholar , 4 Epstein M.R. Saul J.P. Weindling S.N. Triedman J.K. Walsh E.P. Atrioventricular reciprocating tachycardia involving twin atrioventricular nodes in patients with complex congenital heart disease. J Cardiovasc Electrophysiol. 2001; 12: 671-679 Crossref PubMed Scopus (106) Google Scholar or junctional tachycardia in patients with heterotaxy syndrome. 5 Wu M.H. Wang J.K. Lin J.L. Lin M.T. Chiu S.N. Chen C.A. Long-term outcome of twin atrioventricular node and supraventricular tachycardia in patients with right isomerism of atrial appendage. Heart Rhythm. 2008; 5: 224-229 Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar , 6 Toyohara K. Yoshimoto J. Ozaki N. Nakamura Y. Successful catheter ablation of reentrant junctional tachycardia in a patient with asplenia syndrome before total cavo-pulmonary connection. Pacing Clin Electrophysiol. 2010; 33: e43-e45 Crossref PubMed Scopus (5) Google Scholar Herein we describe a patient with right atrial isomerism who required cardiac resynchronization therapy (CRT) because of severe interventricular dyssynchrony due to unilateral AV block.