Appropriate management of syncope in a patient with hypertrophic cardiomyopathy: rationale behind long-term cardiac rhythm monitoring.

We describe the case of a patient with hypertrophic cardiomyopathy who had recurrent syncopal episodes, the cause of which remained unexplained despite a thorough evaluation. Two years after his first evaluation, an implantable loop recorder revealed asymptomatic episodes of advanced second degree atrioventricular block while the patient was awake. Although a permanent pacemaker was implanted, the patient continued to suffer syncopal episodes, during which the pacemaker recorded episodes of ventricular tachycardia. Accordingly, the device was upgraded to an implantable cardioverter-defibrillator.