Potassium-induced cardioplegia: evolution and present status

Most cardiac surgical procedures performed in 1989 are accomplished with the aid of some type of controlled, chemically induced cardiac standstill. Although the physiological principles involved were described in the late 19th century, the first clinical application was not until 1955. Because many surgeons believed that myocardial injury resulted from the toxicity of the agents used, the technique was largely abandoned for about 15 years. With the increasing volume of coronary revascularization surgery and with the need for protection of donor hearts intended for orthotopic transplantation, chemically induced cardiac standstill became more appealing and the technique was revived and reevaluated in several centers. In the last several years, the constitution of cardioplegic solutions and the methods by which they are delivered have been greatly modified. Although the most effective solution and technique may yet remain to be described, unquestionably controlled chemically induced cardiac standstill has contributed substantially to the ease and safety with which cardiac surgical procedures can be accomplished. This vignette, although far from complete, outlines some of the important works that have contributed to the evolution of cardioplegic techniques.