Accumulation of lysophosphoglycerides with arrhythmogenic properties in ischemic myocardium.

Abstract

Lysophosphoglycerides, products of membrane phospholipid catabolism known to influence membrane function in several systems, appeared in the effluents of anoxic isolated rabbit hearts perfused at low flow and accumulated in perfused hearts and myocardium rendered ischemic in situ. Comparable concentrations of lysophosphoglycerides bound to albumin markedly and reversibly altered action potentials of isolated canine Purkinje fibers in vitro. Changes induced included diminution of the maximum diastolic potential, peak dV/dt of phase zero, amplitude, and action potential duration--alterations resembling those seen in ischemic myocardium in vivo. These electrophysiological alterations are compatible with changes implicated in predisposing to dysrhythmia dependent on reentry, a phenomenon potentiated by the presence of zones of decreased conduction. Thus, accumulation of lysophosphoglycerides induced by ischemia may contribute to the genesis of malignant dysrhythmia early after its onset.