Serial electrophysiologic testing with a permanent pacemaker after acute myocardial infarction.

Electrophysiologic testing in patients after acute myocardial infarction may predict subsequent sudden death. We used a permanent pacemaker for repetitive electrophysiologic testing in a patient after acute infarction. Programmed, twice-threshold ventricular extrastimulation at two weeks after anteroseptal infarction failed to induce ventricular tachycardia. Subsequent programmed extrastimulation induced sustained ventricular tachycardia on four occasions (6, 16, 29 and 65 weeks) after infarction. As yet (20 months), spontaneous ventricular tachycardia has not occurred. Firm conclusions cannot be drawn from a single case. However, our patient developed a stable ventricular tachycardia circuit which was not apparent at two weeks. Thus, a single electrophysiologic study performed acutely after infarction may not accurately describe the potential for ventricular tachycardia or fibrillation. Serial electrophysiologic testing with an implantable externally triggered pacemaker may more accurately describe the potential for sudden death post-infarction in a few high-risk patients. This report shows that induction of ventricular tachycardia after acute infarction may not predict outcome.