冠心病患者等长收缩运动与心肌缺血的关系

目的　探讨冠心病患者等长收缩运动与心肌缺血的关系。方法　采用超声多普勒技术 ,比较 2 0例冠心病患者和 10例正常人极量短暂等长收缩运动 (briefisometricexercise ,BIE)、极量持续等长收缩运动(sustainedisometricexercise ,SIE)与动力性运动 (dynamicexercise ,DE)时的血流动力学反应和心功能表现。 结果　有心肌缺血的冠心病患者在DE运动终点时有心肌缺血表现 ,但BIE和SIE时无相应表现。心血管反应总体趋势为 :DE时心率和两项乘积运动增量均明显高于BIE和SIE ,各组间差异不显著。正常组DE时血流动力学多数指标的运动增量均高于BIE和SIE ,但有无心肌缺血的冠心病患者之间无明显差异。结论　在同等主观用力的前提下 ,冠心病患者等长收缩运动时心肌缺血发生率低于动力性运动。等长收缩运动时较高的舒张压和较长的灌注时间对心肌缺血有一定的保护作用。等长收缩运动在冠心病康复中的应用有合理的生理学基础。

Relationship of isometric exercise and myocardial ischemia

Objective To explore correlation between isometric exercise and myocardial ischemia in patients with coronary artery disease (CAD). Methods Twenty CAD patients and 10 normal subjects were required to perform maximal brief and maximal sustained isometric exercise (IE), as well as dynamic exercise (DE). Hemodynamic parameters and cardiac function were measured by Echo Doppler technique. Results Myocardial ischemia during DE was found in all patients with positive exercise testing but not found during the maximal brief and sustained IE. In general, heart rate and rate pressure product during IE were lower than DE. There were no significant differences between groups. Increment of hemodynamic parameters during DE in the normals was higher than IE, but the difference did not exist between CAD patients with and without myocardial ischemia. Conclusion Incidence of myocardial ischemia was lower during isometric exercise than dynamic exercise at similar perceived exertion in patients with CAD. Higher diastolic blood pressure and longer perfusion time of coronary artery during isometric exercise than those during dynamic exercise might have certain protective effect on myocardium. Application of isometric exercise in a cardiac rehabilitation program had reasonable physiological background.