Repetitive beating after single ventricular extrastimuli: incidence and prognostic significance in patients with recurrent ventricular tachycardia.

The incidence of repetitive ventricular beating in response to programmed single ventricular extrastimuli delivered during spontaneous rhythm was tabulated in 59 patients with recurrent ventricular tachycardia. Repetitive beating occurred in only nine patients (15 percent). The repetitive response seemed to be a result of bundle branch reentry in four subjects and possibly a result of other mechanisms in five. There was no difference in the incidence of repetitive beating or type of repetitive response in patients with and without ischemic heart disease. During an average patient follow-up period of 13.6 months, there were eight sudden and six nonsudden deaths. Life table analysis revealed a significantly greater incidence of sudden death in patients with ischemic than in patients with nonischemic heart disease. There was no significant difference in the incidence of sudden death in patients with and without repetitive beating. It is concluded that the repetitive response to single ventricular extra-stimulation is infrequent in patients with recurrent ventricular tachycardia, and that repetitive beating is not a prognostic indicator or an indicator of vulnerability to ventricular tachycardia.