Safety of graded symptom-limited exercise testing in patients with congestive heart failure

The safety and end points of graded symptom-limited bicycle exercise were assessed in 607 patients before they were randomized to vasodilator or placebo in the Veterans Administration Cooperative Study-Vasodilator Heart Failure Trial. Their mean age was 58 years and left ventricular ejection fraction averaged 30%. The peak exercise responses were as follows: oxygen consumption, 14.5 +/- 3.9 ml/kg/min; heart rate, 132 +/- 24 beats/min; systolic blood pressure, 154 +/- 29 mm Hg. No major complications occurred with the baseline tests. The initial baseline test was stopped in only 10 patients (1.6%) for arrhythmias and in one patient for hypotension. Ventricular tachycardia assessed by ambulatory electrocardiographic monitoring during the second exercise test (before exercise, during exercise, and 4 hr after the test) revealed a prevalence of 5.7% during exercise and 28.8% during the rest of the monitoring period. This study has demonstrated that stable male patients with congestive heart failure can safely exercise on a bicycle ergometer to their peak effort in a well-supervised setting. In addition, we have demonstrated that ambulatory electrocardiographic monitoring is a better method than exercise testing to evaluate presence and extent of ventricular arrhythmias in patients with congestive heart failure.