Efficacy of ivabradine to control ventricular arrhythmias in catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal hereditary disease characterized by complex ventricular arrhythmias provoked by exercise or emotional stress and by a high mortality rate in young individuals. Nadolol alone or in combination with flecainide is the most effective therapy. However, compliance to treatment is often low due to side effects. We report two patients with CPVT in whom side effects of treatment prompted discontinuation of flecainide or nadolol and in whom ivabradine was successfully added to therapy. In these two patients, ivabradine in combination with nadolol or flecainide was well tolerated and successfully suppressed nonsustained polymorphic ventricular tachycardia and couplets. Thus, ivabradine could limit the use of implantable cardioverter-defibrillators or left cardiac sympathetic denervation in CPVT patients with uncontrollable ventricular arrhythmias.