Screening and therapy for patients with nonsustained ventricular tachycardia.

Patients with coronary artery disease, nonsustained ventricular tachycardia (VT), and left ventricular dysfunction have an increased risk for sudden cardiac death. Two randomized prospective trials, the Multicenter Unsustained Tachycardia Trial (MUSTT) and the Multicenter Automatic Defibrillator Implantation Trial (MADIT), employed electrophysiologic testing for risk stratification in these types of patients. Individuals with inducible sustained VT were randomized to receive implantable cardioverter defibrillators (ICDs) or "conventional" therapy in MADIT, or were given no specific antiarrhythmic treatment vs electrophysiologically guided therapy in MUSTT. Both trials showed that overall mortality was reduced by approximately 50% with ICD therapy. In MUSTT, patients received no survival benefit with electrophysiologically guided drug treatment. MUSTT also demonstrated that untreated patients with inducible sustained VT had a worse prognosis than patients in whom sustained VT could not be initiated at electrophysiologic study. Even so, the data suggest that electrophysiologic testing alone may not be sensitive enough to identify broader groups of patients at risk for sudden death. In conclusion, patients with nonsustained VT who have coronary artery disease and a left ventricular ejection fraction <0.40 should undergo electrophysiologic testing, and if sustained VT is induced, ICD therapy should be prescribed.