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Cardioplegia is intentional and temporary cessation of cardiac activity, primarily for cardiac surgery. == Overview == The word cardioplegia combines the roots cardio- meaning the heart, and plegia- paralysis.〔http://cancerweb.ncl.ac.uk/cgi-bin/omd?action=Search+OMD&query=cardioplegia〕 Technically this means arresting or stopping the heart so that surgical procedures can be done in a still and bloodless field. Most commonly however, the word cardioplegia refers to the solution used to bring about asystole of the heart, or heart paralysis. The four main goals of hypothermic cardioplegia are: #Immediate and sustained electromechanical quiescence #Rapid and sustained homogenous myocardial cooling #Maintenance of therapeutic additives in effective concentrations #Periodic washout of metabolic inhibitors〔Kaplan J Cardiac Anesthesia. 3rd Edition. W.B Saunders Company. 1993〕 The most common procedure for accomplishing asystole is infusing cold cardioplegic solution into the coronary circulation. This process protects the myocardium, or heart muscle, from damage during the period of ischemia.〔("Cold Crystalloid Cardioplegia" ) Hans J. Geissler * and Uwe Mehlhorn, Department of Cardiothoracic Surgery, University of Cologne〕 To achieve this, the patient is first placed on cardiopulmonary bypass. This device, otherwise known as the heart-lung machine, takes over the functions of gas exchange by the lung and blood circulation by the heart. Subsequently the heart is isolated from the rest of the blood circulation by means of an occlusive cross-clamp placed on the ascending aorta proximal to the innominate artery. During this period of heart isolation the heart is not receiving any blood flow, and thus no oxygen for metabolism. As the cardioplegia solution distributes to the entire myocardium the ECG will change and eventually asystole will ensue. Cardioplegia lowers the metabolic rate of the heart muscle thereby preventing cell death during the ischemic period of time. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cardioplegia」の詳細全文を読む スポンサード リンク
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