Institut universitaire de cardiologie et de pneumologie de Québec, Quebec, Canada.
Am J Cardiol. 2010 Mar 1;105(5):633-9. doi: 10.1016/j.amjcard.2009.10.057.
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 (> or =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 x systolic blood pressure product at 1-mm ST-segment depression) and oxygen consumption (VO(2)). The ischemic threshold was higher during cycling (ergocycle ramp, 24,009 +/- 5,769 beats/min x mm Hg) compared to running (Bruce treadmill, 20,429 +/- 3,508 beats/min x mm Hg; and ramp treadmill, 19,451 +/- 3,392 beats/min x mm Hg; p <0.001), independently of exercise intensity (VO(2)). The peak VO(2) did not significantly differ among all tests (p = 0.25) despite a greater peak rate-pressure product achieved with the ergocycle (29,378 +/- 6,291 beats/min x mm Hg) compared to either treadmill protocol (Bruce, 26,202 +/- 5,831 beats/min x mm Hg; ramp, 25,654 +/- 6,492 beats/min x mm Hg; p <0.001). In conclusion, the mode of exercise (ergocycle vs treadmill), rather than the type of protocol (ramp vs Bruce), is associated with an attenuation of electrocardiographic parameters of myocardial ischemia, independently of exercise intensity (VO(2)) and myocardial demand (rate-pressure product).
我们先前观察到，在患有冠心病的患者中，与标准 Bruce 方案跑步机测试相比，在斜坡方案期间，在健身车上的运动引起的心肌缺血程度降低。但是，尚不确定健身车上的缺血程度是由于更渐进的斜坡方案的热身效应，还是由于运动本身的模式（骑车与跑步）所致。16 名稳定的冠心病患者（> 70%的冠状动脉狭窄和/或可逆转的心肌灌注缺陷），年龄 64 ± 5 岁，进行了 3 次症状限制的运动测试：标准 Bruce 方案跑步机测试和 2 种个体化的斜坡方案（跑步机和健身车）。我们测量了缺血阈值（ST 段压低 1mm 时的心率 x 收缩压乘积）和耗氧量（VO2）。与跑步（Bruce 跑步机，20429 ± 3508 次/分钟 x 毫米汞柱；和斜坡跑步机，19451 ± 3392 次/分钟 x 毫米汞柱）相比，在骑车时（健身车斜坡，24009 ± 5769 次/分钟 x 毫米汞柱），缺血阈值更高（p <0.001），而与运动强度（VO2）无关。尽管在健身车上达到的峰值率压乘积更高（29378 ± 6291 次/分钟 x 毫米汞柱），但所有测试之间的峰值 VO2 均无显著差异（p = 0.25）（与 Bruce 跑步机相比，26202 ± 5831 次/分钟 x 毫米汞柱；与斜坡跑步机相比，25654 ± 6492 次/分钟 x 毫米汞柱；p <0.001）。总之，运动方式（健身车与跑步机），而不是方案类型（斜坡与 Bruce），与心电图参数的心肌缺血减轻有关，而与运动强度（VO2）和心肌需求（率压乘积）无关。
