Sleep and Ventricular Premature Beats

Sixty-nine 24-hour electrocardiographic monitoring sessions were conducted in 54 ambulatory subjects. Thirty-one had coronary heart disease (CHD); 11 had miscellaneous heart ailments; and 12 were free of any heart disease. Monitoring was accomplished with a miniaturized cassette recorder and ventricular premature beats (VPBs) were analyzed as to incidence and grade. The occurrence of VPBs during sleep hours was compared to the awake state. In 22 patients, the incidence of VPBs was reduced by at least 50% during sleep. An additional 13 patients showed a reduction of 25 to 50%. If patients free of ectopic activity during 24-hour monitoring sessions are excluded from analysis, then in 35 of 45 patients, or in 78%, sleep was associated with a lowered occurrence of ventricular extrasystoles. During sleep the VPB grade was likewise lowered. Thus the mean grade for 45 patients changed from 2.75 while awake to 1.78 while asleep. It is of interest that in a number of these patients, trials of various antiarrhythmic drugs were less effective than sleep in reducing the incidence and grade of VPBs. It is concluded that treatment of sporadically occurring ventricular ectopic activity in some patients may require attention to the neurophysiologic trigger rather than the cardiac target.