Prevalence and long-term significance of exercise-induced frequent or repetitive ventricular ectopic beats in apparently healthy volunteers.

Frequent or repetitive exercise-induced ventricular ectopic beats are often considered a marker for serious cardiac disease or sudden death, or both. However, the prognostic value of these arrhythmias in an unreferred asymptomatic community-dwelling population over a broad age range is unknown. Of 1,160 subjects aged 21 to 96 years who underwent maximal exercise treadmill testing an average of 2.4 times, 80 (6.9%) developed frequent (greater than or equal to 10% of beats in any 1 min) or repetitive (greater than or equal to 3 beats in a row) ventricular ectopic beats on at least one test. These 80 individuals were significantly older than the group without such arrhythmia (63.8 +/- 12.5 versus 50.0 +/- 16.1 years, p less than 0.0001). A striking age-related increase in the prevalence of frequent or repetitive exercise-induced ventricular ectopic beats was seen in men (p less than 0.0001) but not in women. The prevalence of electrocardiographic abnormalities at rest, exercise-induced ST segment depression and thallium perfusion defects, duration of treadmill exercise, maximal heart rate, systolic blood pressure and rate-pressure product did not differ between these 80 study subjects with frequent exercise-induced ventricular ectopic beats and a control group matched for age and gender. Furthermore, the incidence of cardiac events (angina pectoris, nonfatal myocardial infarction, cardiac syncope or cardiac death) (10% versus 12.5%) as well as noncardiac mortality (each 7.5%) was found to be similar for the study and control groups, respectively, over a mean follow-up period of 5.6 years. No study subjects required antiarrhythmic drugs over this time interval.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence and prognostic significance of exercise-induced supraventricular tachycardia in apparently healthy volunteers.

The prevalence, characteristics, and prognostic significance of supraventricular tachycardia (SVT) occurring during maximal treadmill exercise testing were examined in 843 male and 540 female asymptomatic volunteers aged 20 to 94 years from the Baltimore Longitudinal Study of Aging who underwent exercise testing a mean of 2.3 times between 1977 and 1991. Exercise-induced SVT occurred during at least 1 test in 51 men (6.0%) and 34 women (6.3%), p = NS for gender. The 85 subjects with exercise-induced SVT were significantly older than the 1,298 free from this arrhythmia (66.0 +/- 13.5 vs 49.7 +/- 18.0 years, respectively, p < 0.001). The prevalence of SVT increased with age in men (p < 0.001) but not in women. Ninety-eight percent of the 141 discrete episodes of exercise-induced SVT were paroxysmal SVT, with heart rates varying from 105 to 290 beats/min (mean 186.3 +/- 43.3); only 16% were > 10 beats in duration and only 4% of subjects were symptomatic. Nearly half (44%) of SVT episodes occurred at peak effort. Coronary risk factors, echocardiographic left atrial size (3.3 +/- 6.7 vs 3.3 +/- 0.6 cm), and the prevalence of exercise-induced ischemic ST-segment depression (11% vs 13%) were similar in 85 subjects with SVT and 170 control subjects matched for age and sex.(ABSTRACT TRUNCATED AT 250 WORDS)