Treatment of ventricular tachycardia induced cardiogenic shock by percoronary chemical ablation. Incessant ventricular arrhythmias pose an especially challenging therapeutic dilemma. We describe the successful treatment and follow-up of a patient with refractory ventricular tachycardia-induced cardiogenic shock with percoronary chemical ablation. After endocardial mapping was used to identify the "tachycardia-related" coronary artery, temporary termination of the arrhythmia with balloon occlusion and subselective intracoronary installation of iced saline as previously advocated was unsuccessful. This was probably due to a dual arterial blood supply to the arrhythmogenic focus. However, infusion of 2 cc ethanol (99%) permanently terminated the arrhythmia. Contrary to previous experience, ethanol-induced arrhythmia termination did not result in arterial occlusion, further supporting a direct toxic effect on the myocardium as its mode of action. Use of standard angioplasty balloon inflation prevents "backwash" of distally infused ethanol and more generalized cell death. The only complication of this procedure was temporary third-degree AV block, requiring permanent pacemaker implantation. 