Histologic observations after closed chest ablation of the atrioventricular conduction system

Postmortem examination of the heart was done in a case with disabling supraventricular tachyarrhythmia successfully treated by closed-chest ablation of the His bundle. A ventricular aneurysm developed as a result of a previous myocardial infarction, and death occurred suddenly five months after the procedure. Histologic studies of the atrioventricular (AV) junctional tissue demonstrated severe damage to the nearby AV node and penetrating His bundle. No damage to the branching His bundle or either bundle branch was observed.