Prevention of ventricular fibrillation by pacing in a man with Brugada syndrome

The unique ECG appearance of Brugada syndrome is caused by failure of the d ome of the action potential to develop. It occurs when the outward currents (mainly I-to) overwhelm the inward currents (mainly I-ca) at the end of ph ase 1 of the action potential. Because I-to becomes less prominent at a fas ter rate, increased heart rate is associated with decreased ST segment elev ation on ECG and probably decreased incidence of ventricular arrhythmia, We present the first report on prevention of ventricular fibrillation in a ma n with Brugada syndrome by overdrive pacing from his dual chamber implantab le cardioverter defibrillator.