Preischemic perfusion of hypertrophied myocardium with perfluorocarbons.

The increased susceptibility of hypertrophied myocardium to ischemic injury is well known. Hypertrophied hearts possess lower preischemic high energy phosphate stores and develop ischemic contracture following a shorter ischemic interval than normal hearts. The purpose of this study was to determine the ability of preischemic, arrested perfusion of the hypertrophied rat heart with oxygenated, glucose-containing perfluorocarbon cardioplegia (FC-43) to restore myocardial ATP stores to normal and prolong the duration of global ischemia prior to contracture initiation. Hearts from normal (NL) rats and hypertrophied hearts from spontaneously hypertensive rats (SHR) were subjected to 2 or 15 min of preischemic, arrested perfusion with FC-43 utilizing a modified Langendorff preparation. ATP was determined via HPLC and time to initiation of ischemic contracture was measured. Two minutes of FC-43 perfusion restored ATP in the SHR group to normal levels (P = NS compared to normal controls) and prolonged the time to initiation of ischemic contracture by 107%. Perfluorocarbons, with their unique oxygen-carrying properties, may be an ideal vehicle for intervention designed to enhance the tolerance of hypertrophied hearts to ischemia.