等长收缩运动治疗冠心病患者作用机理探讨

等长收缩运动是日常生活中不可缺少的运动形式之一，由于运动训练效应的特异性，不训练即可产生不适应性。过去认为等长收缩运动强度较难掌握，又可能同时存在Ｖａｌｓａｌｖａ效应而产生过程的心血管反应，可能对心脏病患者不利，从而在康复治疗中未得到应有的重视。本文通过对１８名健康青年（平均２３．７岁）进行等长收缩运动，应用β阻滞剂和阿片肽拮抗剂模拟特定的神经调控环境，发现等长收缩运动时的心血管反应受交感神经和阿

Mechanism of Isometric Exercise in Cardiac Rehabilitation

Isometric exercise(IE) is an essential component of daily living activities.Lack of IE may result in deconditioning of IE capacity.IE has not been used in cardiac rehabilitation because of poor understanding in cardiovascular response to IE and the Valsalva Maneuver associated with IE.Eingteen healthy young subjects aged 23.7 yrs on average was studied by administration of beta blocker and antagonist of opioids during IE.The result demonstrated that the regulation of cardiovasular response during IE is attributed to both sympathetic system and opioids activity.Twenty patients with coronary artery disease (CAD) were also studied during brief maximal IE,sustained maximal IE and dynamic exercise(DE).The patients included 13 cases with more than one vessel lesions and 7 post myocardial infarction and/or angina.Ten age matched apparent healthy subjects were examined as the control group. The result showed that IE without the Valsalva Maneuver in patients with CAD might increase coronary artery perfusion by enhancing diastolic pressure and prolonging diastolic period,which had no harmful effect on CAD.Hemodynamic responses and cardiac function were weaker during IE than DE.The intensity of the responses to IE was correlated to the central command but not to the absolute work load.It is concluded that significant release of endogenous opioids due to strong central command during IE,especially perceived maximal sustained IE,may help to attenuate activity of sympathetic system,thus reducing risk of exercise in patients with CAD.