Range of ventricular ectopic complexes in healthy subjects studied with repeated ambulatory electrocardiographic recordings.

The incidence and forms of ventricular premature complexes (VPCs) in apparently healthy subjects were studied to determine long-term reproducibility of day to day variation on Holter electrocardiogram. The study included 152 men and 68 women ranging in age from 20 to 78 years who were having routine check-ups that revealed no cardiovascular abnormalities. In addition to routine measurements, Holter electrocardiography was recorded during daily life, and the total number of VPCs occurring during 24 hours was visually calculated on replayed electrocardiographic tracings. Forms of VPCs and incidence of VPCs in 10-year age groups of the subjects were also recorded. No VPCs were observed in 56% of the subjects; 93% showed less than 50 VPCs and the other 7% of the 220 subjects had greater than or equal to 50 VPCs. Forty-one of the 220 subjects returned for routine follow-up 1 year later. Repeated Holter electrocardiograms at this time showed high reproducibility of less than 50 VPCs. A small number of multiform VPCs were reproducible but paired VPCs were not. Physiologic definition of VPCs in healthy subjects appears to be clinically significant.