Long-term Outcome in Asymptomatic Men with Exercise-Induced Premature Ventricular DepolarizationsAbstracts & commentary
Synopsis: Apparently well males who exhibit frequent PVCs during exercise have a higher rate of both cardiovascular as well as all-cause mortality.
Sources: Jouven X, et al. N Engl J Med 2000;343:826-833; Calkins H. N Engl J Med 2000;343:879-880.
During the period of 1967 to 1972, jouven and colleagues subjected 93.4% of all apparently well male Paris Civil Service employees to a standard bicycle exercise stress test with the objective of determining the short- and long-term prognosis associated with premature ventricular contractions (PVCs) occurring at rest, during exercise, and during the immediate post-exercise period. At entry, subjects ranged from 42 to 53 years of age. Apparently well was defined as lacking a systolic BP more than 180 mm Hg, having no history of diabetes mellitus, and having no abnormality on a standard resting 12-lead ECG. Subjects were followed until January 1, 1991—a total of 23 years. Vital statistics were available for all but 355 (5.5%) of the 6456 subjects.
Exercise testing was positive for ischemia in 4.4% of subjects. Frequent PVCs occurred before exercise in 0.8%; during exercise in 2.3%; and in 2.9% during recovery from exercise. Infrequent premature contractions occurred before exercise in 2%; during exercise in 8.5%; and, in 7.3% during recovery from exercise. During the 23 years of follow-up, no difference was found in either overall or cardiovascular mortality rate between those who had none, infrequent, or frequent PVCs before exercise. In striking contrast, subjects who had frequent PVCs during exercise had a significantly higher all-cause (41.3%) and cardiovascular mortality (16.7%) compared to those who had either no (27.9% all-cause and 16.7% CV) or infrequent VPBs (26.3% all-cause and 6.8% CV) during exercise. Those who had frequent PVCs during the recovery phase had a higher all-cause mortality rate but did not have a higher CV mortality rate than those with no or infrequent PVCs.
Significantly, subjects who demonstrated ischemic ECG changes during exercise rarely exhibited frequent PVCs; conversely, those who demonstrated frequent PVCs during exercise rarely demonstrated ischemic ECG changes. Jouven et al make the following conclusions: 1) apparently well males who exhibit frequent PVCs during exercise have a higher rate of both cardiovascular as well as all-cause mortality; 2) the reason for this PVC-related increase is something other than ischemic heart disease; and 3) the long-term increase in cardiovascular mortality associated with exercise-induced PVCs is of the same magnitude as that associated with ischemia. Jouven et al suggest that exercise-induced PVCs may reflect the effects of catecholamines and/or may reflect that these subjects had some form of cardiomyopathy (for example, right ventricular dysplasia).
Comment by Michael K. Rees, MD, MPH In an accompanying editorial, Calkins remarks that, "remarkably little is known about the long-term prognostic implications of exercise-induced ventricular arrhythmias." He notes that the study by Jouven et al is the first to evaluate their prognostic implications. Clinicians now know that exercise-induced PVCs are not benign and that individuals who exhibit some require further careful investigation and regular long-term follow-up.