Myocardial protection during cardioplegia in open-heart surgery: a review

Abstract

The use of cardioplegia (pharmacologically induced electromechanical arrest) to achieve the ideal conditions for cardiac surgical operations was introduced over 20 years ago in clinical practice. Since then a number of ingredients have been added in various proportions to different cardioplegic solutions and their evaluation in experimental laboratories and clinical practice has continued. Any additive to a cardioplegic solution should be investigated in experimental laboratories and asanguinous cardioplegic solutions should be carefully formulated to avoid extremes of ionic concentrations, pH and osmolarity. Cold blood cardioplegia has not been found advantageous when compared with conventional asanguinous solutions. A combination of pharmacologically induced arrest with cold asanguinous cardioplegic solution and topical hypothermia protects the myocardium better than topical hypothermia alone or normothermic cardioplegia, and continuous infusion of cardioplcgic solutions has proved no better.than multidose administration. Multidose administration of cold eardioplegie solutions with moderate hypothermia and surface cooling has been found most satisfactory for prolonged aortic cross clamping (up to two hours). Use of cardioplegia in recent years has undoubtedly improved the prognosis of a number of patlents undergoing surgical correction of complex cardiac lesions.CARDIAC SURGICAL PROCEDURES often require a bloodless, relaxed and motionless field during operation, which is easily accomplished by ischaemic arrest induced by cross clamping the aorta. Any period of ischaemia is accomplished by metabolic and structural changes which determine the functional recovery of the heart in the postoperative period. The safe period of ischaemia for the human heart is not clearly defined but 20-30 minutes is generally considered the upper limit. When aortic cross clamping time exceeds this period substantial subendocardial necrosis may occur, with low output syndrome in the postoperative period. The need for protection of the myocardium during ischaemic arrest has been well recognized and a number of methods including local t and systemic hypothermia, 2 intermittent coronary perfusion) retrograde coronary perfusion with cold blood, 4 coronary perfusion with cold lactated Ringer's solution, s tetrodoxin, 6 acetylcholine,7 chemical asanguinous K + cardioplegia, s cold blood cardioplegia, 9 have been used in experimental studies and clinical practice. Of these, hypothermia and pharmacological arrest with cold cardioplegic solutions have now gained wide acceptance in clinical practice.Department of Anaesthesia and Cardiovascular Unit, Killingbeck Hospital, Leeds, England.Reprint requests to Dr. R.R. Chatrath, Consultant Anaesthetist, Killingbeck Hospital, Leeds, LS 14 6UQ, England.Canad. Anaesth. Soc. J., vol. 27, no. 4, July 1980 METHODS OF MYOCARDIAL PROTECTION Topical hypothermiaHypothermia has been proved to be an effective method of myocardial preservation. It provides a bloodless arrested heart, lowers the energy re...

Myocardial protection in cardiac surgery: how limited are the options? A comprehensive literature review

“…Cardioplegia is an essential cardioprotective pharmacological therapy for electromechanical cardiac arrest during cardiac surgery. 1 This is achieved by altering cellular electrochemical gradients to reduce myocardial metabolic demands by inducing electrical quiescence. In addition, cooling of the myocardium is thought to minimise the ischaemia-reperfusion injury (IRI) associated with cardiopulmonary bypass, which is a significant cause of mortality and morbidity in cardiac surgery.…”

CIRP Secretion during Cardiopulmonary Bypass Is Associated with Increased Risk of Postoperative Acute Kidney Injury

“…During cardiac surgery, cold cardioplegia solution is infused into the heart through the coronary artery. 19 After that, cardiomyocytes experience hypothermia and hypoxia, which may induce the secretion of CIRP. In addition, theblood supply of the whole body changes from pulsatile perfusion to advection perfusion, and oxygen supply of organs will change to some extent.…”

Protective Efficacy on Adult Ischemic Myocardium under Bypass: Del Nido vs. St. Thomas Blood Cardioplegia

“…Since the 1950s, a variety of cardioplegia solution differed in their electrolyte and drug additives have been adopted. 1) The basic principle is diastolic arrest induced and maintained with potassium added to either blood-based or crystalloid-based solution. 2) However, so far there is still lack of a clear consensus on the optimal composition.…”