Significance of ventricular pauses of three seconds or more detected on twenty-four-hour Holter recordings.

The natural history of patients with asymptomatic prolonged ventricular pauses and the indications for permanent pacing are controversial. To examine this problem, 6,470 consecutive 24-hour Holter recordings were reviewed between 1979 and 1983 for the presence of ventricular pauses of at least 3 seconds. Fifty-two patients (0.8% of total), 22 men and 30 women, were identified with an average longest pause duration of 4.1 seconds. Holter recordings were requested to evaluate syncope in 14 patients (27%), dizziness in 9 (17%) and other reasons in 29 (56%). Causes of the pauses were sinus arrest in 22 patients, atrial fibrillation with slow ventricular response in 18 patients and atrioventricular block in 12. Holter recordings were also evaluated for the presence of tachyarrhythmias. Six patients had nonsustained ventricular tachycardia and 7 had supraventricular tachycardia. Five of the 52 patients (10%) had dizziness or syncope during pauses. Twenty-six patients (50%) received permanent pacemakers. The paced (26 patients) and unpaced (26 patients) groups were similar in the length and etiology of pause, associated tachyarrhythmias, presence of bradycardia-related symptoms, prevalence of organic heart disease, medications and length of follow-up. Four patients in the paced group and 2 in the unpaced group died, yielding 3-year actuarial survival probabilities of 78% and 85%, respectively. It is concluded that ventricular pauses of 3 seconds or longer are uncommon, these pauses usually do not cause symptoms, and the presence of these pauses does not necessarily portend a poor prognosis or the need for pacing in asymptomatic patients.