Transthoracic epicardial catheter ablation to treat recurrent ventricular tachycardia.

Nonsurgical epicardial transthoracic catheter ablation is a minimally invasive procedure that has proven to be efficacious for the treatment of ventricular tachycardia (VT). The usefulness of this technique depends on the prevalence of epicardial circuits, which seem more frequent in Chagasic than post-myocardial infarction VT. This approach is limited by concern regarding the potential adverse effects of radiofrequency (RF) ablation on the coronary arteries. However, the effects of RF ablation delivered in the vicinity of a major coronary artery are limited to the medial artery. Severe intimal hyperplasia and intravascular thrombosis may occur only when RF ablation is delivered above the artery. Moreover, susceptibility to damage is inversely proportional to the vessel size. Coronary artery injury is an uncommon (< 1%) complication that could be prevented by a coronary angiogram prior to ablation. Hemopericardium, another predictable complication occurring in 10% of patients, can be easily controlled in the electrophysiology laboratory.