Subcutaneous implantable cardioverter-defibrillator implantation for ventricular fibrillation caused by coronary artery spasm: a case report.

Background: Coronary artery spasm usually has a good prognosis, except when it induces lethal ventricular arrhythmias. Implantable cardioverter-defibrillator (ICD) implantation in addition to optimal medical therapy including prescription of coronary vasodilators and smoking cessation is a therapeutic option for coronary artery spasm patients who present with lethal ventricular arrhythmia. Subcutaneous ICDs are now available as an alternative to conventional transvenous ICDs.

Case Summary: We report the first case of a 50-year-old Japanese male without any structural heart disease who presented with ventricular fibrillation caused by coronary artery spasm, and underwent subcutaneous ICD implantation for secondary prevention of sudden cardiac death (SCD). We attributed his aborted SCD to coronary artery spasm based on findings of cardiac catheterization including acetylcholine provocation test and cardiac electrophysiological study. During the 1 year of follow-up, the patient discharged on calcium channel blockers and nicorandil has been free of angina, ventricular arrhythmias, and appropriate ICD therapy.

Discussion: Coronary artery spasm patients with aborted SCD may be good candidates for implantation of subcutaneous ICDs, because most of them have no need for concomitant bradycardia therapy, cardiac resynchronization therapy, or anti-tachycardia pacing therapy.