Repetitive ventricular response. Prevalence and prognostic significance.

re-entry andbundle-branch re-entry in47patients withand in50patients without ventricular tachycardia. We alsocompared theprevalence ofrepetitive ventricular responsesusing twotypesofelectrophysiological stimulation: single prematureventricular stimulation during sinus rhythm oratrial pacing, andsingle prematureventricular stimulation during ventricular pacing.Inpatients whohadventricular tachycardia, prematureventricular stimulation during ventricular pacing induced non-bundle-branch re-entry more often thanduring atrial pacing (70-2% versus333%).Bothmethods ofstimulation induced non-bundle-branch re-entry more often inpatients whohadventricular tachycardia thaninthose whodidnot.Inbothgroupsof patients, bundle-branch re-entry was rareduring atrial pacing andmore common butequally prevalent during ventricular pacing. Todetermine ifinduced non-bundle-branch re-entry could identify patients atrisk ofdeveloping future symptomatic ventricular tachycardia or sudden death, 59patients whohada history of documented ventricular tachycardia hadanelectrophysiological study just before discharge andwere followed for anaverageof109months. Non-bundle-branch re-entry induced during ventricular and atrial pacing hadapredictive accuracyof59%and64%,respectively. Thepredictive accuracyof non-bundle-branch re-entry induced during atrial pacing appeared tobegreaterinpatients whoalso hadventricular tachycardia induced during the sameelectrophysiology