Occurrence of Ventricular Arrhythmias with Exercise as Compared to Monitoring

Treadmill exercise testing and prolonged ambulatory electrocardiographic monitoring were compared for their ability to reveal ventricular ectopic activity in 81 patients. Both proved more effective than a 3-minute standard electrocardiogram (ECG) in displaying ventricular arrhythmias. Of 66 patients in whom the resting ECG was normal, prolonged monitoring was positive for arrhythmia in 18, or 27%, whereas exercise was positive in 26, or 39%. In 12 cases ventricular arrhythmia was recorded only with exercise. In addition to displaying an increased incidence of arrhythmia, exercise also revealed more serious rhythm abnormalities which would not have been suspected on monitoring alone. This was true in patients with and without coronary heart disease (CHD). Thus, exercise is an effective means of eliciting suspected arrhythmias. The prognostic significance of exercise-induced arrhythmias in patients with CHD remains to be determined.