Failure of cilostazol in the prevention of ventricular fibrillation in a patient with Brugada syndrome.

The ECG appearance in Brugada syndrome is caused by failure of the dome of the action potential to develop. Increased activity of the I(to) current in epicardial cells generates a transmural gradient with repolarization dispersion between the epicardium and the endocardium in the right ventricular wall, thus favoring the development of VF by a phase 2 reentry mechanism. The efficacy of cilostazol for the management of these arrhythmias has been reported. This drug is a phosphodiesterase inhibitor with positive chronotropic properties, thus blocking outward potassium currents I(to) in the myocardial tissue. We present a patient with Brugada syndrome with an implantable cardioverter defibrillator (ICD), who suffered multiple ICD discharges due to VF during therapy with this drug.