Electrophysiologic follow-up in dogs receiving intracoronary ethyl alcohol injection

96% ethyl alcohol was injected into a diagonal branch of the left anterior descending coronary artery of 10 out of 12 anesthetized dogs, and saline solution was injected in the remaining 2. After chest closure, the dogs were subjected to ambulatory monitoring (H) during days 1, 2, 3 and 7. The electrophysiologic study (EPS) and signal-averaged electrocardiography. (SA-ECG) were performed before the injection and again at day 7 after injection. H failed in one dog which died of ventricular fibrillation. In the other 9 dogs that received alcohol injection, H showed frequent ventricular premature and ventricular tachycardia (VT) after injection; six of the 9 dogs sustained VT, which was not inducible by EPS. VT was not found in 2 control dogs receiving saline solution injection. The SA-ECG showed no ventricular late potentials in dogs receiving alcohol injection. Post-ablation ventricular arrhythmia (including VT) occurred after intracoronary ethyl alcohol injection in all dogs. Arrhythmogenicity markedly declined during the first 3 days and almost completely disappeared on day 7 after ablation. There was no evidence in favor of reentry as the mechanism of these arrhythmias. Enhanced automaticity was considered as the mechanism for ventricular arrhythmia.