Bachmann's bundle-ridge related biatrial tachycardia with a long epicardial circuit.

Biatrial tachycardia (BiAT), involving Bachmann's bundle in the circuit, has sometimes been observed after mitral anterior line ablation. In this article, we present a case of BiAT, involving a long epicardial circuit, composed of Bachmann's bundle and the left atrial ridge (LAR). We discuss the optimal ablation technique for this tachycardia based on our experience in addition to the relationship between Bachmann's bundle and the LAR. Furthermore, the evaluation method for the mitral anterior block line is also discussed.