Epicardial conduction via the septopulmonary bundle visualized by an esophageal temperature catheter in macroreentrant atrial tachycardia

The left atrial posterior wall (LAPW) plays a key role in the occurrence and maintenance of atrial fibrillation, an irregular heartbeat that can lead to blood clots and stroke. Posterior wall isolation may be an effective treatment in patients for whom pulmonary vein isolation alone is insufficient.1,2 However, the presence of the septopulmonary bundle (SPB), which runs vertically along the LAPW, often makes this isolation difficult.3,4 In this report, we present a case in which an esophageal temperature catheter was useful for identifying the circuit of macro-reentrant tachycardia in the left atrium via the SPB induced after posterior wall isolation.