Comparison of Myocardial Ischemia on the Ergocycle Versus the Treadmill in Patients With Coronary Heart Disease

We previously observed an attenuation of exercise-induced myocardial ischemia on the ergocycle during a ramp protocol compared to the standard Bruce protocol treadmill test in patients with coronary heart disease. However, it was uncertain whether decreased ischemia on the ergocycle resulted from the warm-up effect of the more gradual ramp protocol or from the mode of exercise itself (cycling vs running). Sixteen stable patients, aged 64 ± 5 years, with documented coronary heart disease (≥70% coronary artery stenosis and/or reversible myocardial perfusion defects) performed 3 symptom-limited exercise tests: the standard Bruce protocol treadmill test and 2 individualized ramp protocols (treadmill and ergocycle). We measured the ischemic threshold (heart rate × systolic blood pressure product at 1-mm ST-segment depression) and oxygen consumption (V̇O2 ). The ischemic threshold was higher during cycling (ergocycle ramp, 24,009 ± 5,769 beats/min × mm Hg) compared to running (Bruce treadmill, 20,429 ± 3,508 beats/min × mm Hg; and ramp treadmill, 19,451 ± 3,392 beats/min × mm Hg; p