Myocardial preservation 1987: what is the state of the art?

The principles of myocardial preservation by hypothermic cardioplegia are: to induce cardiac arrest rapidly, to minimize energy requirements and prevent ischaemic damage during arrest, and to avoid reperfusion injury after arrest. These principles are put into practice by infusing an effective cold cardioplegic solution at the beginning of ischaemia and then every 20-30 min throughout ischaemia. Myocardial temperature should be maintained below 15 degrees C in all areas of the myocardium by topical cooling, efficient venous drainage and cardiac venting. The use of an oxygenated blood-based cardioplegic solution produces a modest improvement in myocardial recovery compared with a non-oxygenated crystalloid solution. During coronary reperfusion after arrest, ventricular distension should be avoided and coronary pressure should be sufficiently high to perfuse all areas of the myocardium, especially in patients with coronary stenoses. Developing areas in myocardial preservation include metabolic supplementation of the myocardium, the use of free radical scavengers, the prevention of atrial arrythmias and the use of coronary sinus cardioplegia. The increasing numbers of high risk patients presenting for surgery should stimulate the surgeon to adhere closely to the basic principles of myocardial preservation and to apply existing cardioplegic techniques meticulously. It should also challenge the investigator to increase basic understanding and improve methodology in this important area of cardiac surgery.