[Repetitive ventricular response by programmed electrostimulation of the heart: frequency and clinical significance]

The induction of a repetitive ventricular response (RVR) by programmed electrical stimulation (PES) in patients with malignant ventricular arrhythmias such as ventricular tachycardia or ventricular fibrillation is associated with poor prognosis. However, the incidence and clinical significance of RVR in patients with normal hearts and in those with coronary artery disease (CAD) who do not have a history of malignant ventricular arrhythmias are unknown. In this paper, we present our views on the clinical value of PES in those patients. The incidence of RVR in patients without evidence of heart disease remains controversial. The possible reasons for the disparities between studies are due to differences in the study populations and stimulation protocols used. In 38 patients with normal hearts proven by left ventricular and coronary angiography no patient had three or more ventricular depolarizations in response to PES with single and double premature stimuli. The same stimulation protocol was used in 136 patients with coronary artery disease. The incidence of RVR greater than or equal to 3 (three or more ventricular depolarizations in response to PES) was related to the time interval to prior acute myocardial infarction and to the degree but not to the extent of left ventricular wall motion abnormalities. The relationship between spontaneous ventricular arrhythmias and those induced by PES was compared in 267 patients. Although there was some correlation between absence or presence of both types of arrhythmias, the presence of RVR greater than or equal to 3 did not predict precisely the presence of high grade ventricular arrhythmias during Holter-monitoring. The prognostic significance of RVR greater than or equal to 3 in patients with chronic stable coronary artery disease remains to be determined. However in patients with recent acute myocardial infarction it has been found that subjects at risk of sudden death (SD) can be identified by PES. We feel that until the prognostic significance of RVR is better defined its use as a basis for guiding antiarrhythmic therapy is not warranted.