Monogenic and oligogenic cardiovascular diseases: genetics of arrhythmias—catecholaminergic polymorphic ventricular tachycardia

Abstract

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited disorder associated with syncope and sudden death manifesting in the young during sympathetic activation. The electrocardiogram is normal and the heart is structurally normal. The diagnosis is usually made with an exercise stress test that shows a typical pattern of onset and offset of adrenergically induced ventricular arrhythmias. Molecular screening of RyR2, the major CPVT gene, is recommended whenever the suspicion of CPVT is high. If a disease-causing mutation is identified, cascade screening allows pre-symptomatic diagnosis among family members. All affected subjects should be treated with beta blockers (nadolol or propranolol). Preliminary data support the association of beta blockers with flecainide. After a cardiac arrest, an implantable cardioverter defibrillator (ICD) should be implanted, but it is accompanied by a disquietingly high incidence of adverse effects. After syncope on beta blocker therapy, left cardiac sympathetic denervation is most effective, preserves quality of life, and does not preclude a subsequent ICD implantation.