ALCOHOL ABLATION FOR TACHYCARDIA THERAPY

Selective administration of ethanol into branches of the coronary arterial circulation has been proposed as a means of ablating cardiac fibers that give rise to cardiac arrhythmias, no matter where in the heart they might be located. In patients with uncontrollable ventricular rates in the setting of atrial fibrillation or atrial flutter, ethanol has been infused into the atrioventricular (AV) nodal artery in order to abolish or modify AV nodal conduction. Such a procedure is technically feasible in approximately 80% of patients and is successful in 70%-80% of individuals who are treated. Many of these patients require permanent pacemaker implantation because of chronic complete AV block. Intracoronary ethanol ablation has also been used to treat patients with AV nodal reentrant supraventricular tachycardia and ectopic atrial tachycardia, but there is scant clinical experience with the technique in these arrhythmias. Among patients with incessant or recurrent ventricular tachycardia (VT), intracoronary ethanol ablation has abolished clinical recurrences of arrhythmia in 78% of treated individuals. However, inability to identify a VT-related arterial branch and other technical considerations may limit application of ethanol ablation to fewer than 50% of potential candidates with VT. Ethanol ablation is generally well tolerated, but: significant complications have occurred, including ethanol-induced occlusion of nontarget coronary arteries leading to unintended myocardial infarction. Procedure-related death has also occurred. Ethanol ablation shows promise as a method for abolishing intractable tachycardias but further study is required to improve the safety of the technique and to define more precisely which patients are the best candidates in whom to consider this approach.