Epicardial connection between superior vena cava and right atrium contributes to subsequent atrial fibrillation: a case report

Although the mechanisms of ECs in the SVC and RA have not been entirely elucidated, several potential mechanisms have been proposed. (i) Anatomically inherited myofibres/bundles may run through the epicardial side between the SVC and RA. (ii) Epicardial connections between the right PV and the SVC or RA have been recently reported. Thus, we might speculate on the possibility of the existence of EC(s) between the right PV and both the SVC and RA. After cryoablation in the first session, the connection between the SVC and RA remained, which might have acted as EC(s). Thus, physicians should consider the possibility of EC(s) when remaining potentials in the SVC are observed, even though the SVC isolation line seems to be completed.