Differences in electrical and mechanical recovery from @entity63 XXXX and cardioplegia.

@entity63 @entity713 @entity8162 @entity2224 @entity460 @entity594 @entity35 @entity1167 @entity943 @entity413
The course of recovery of heart activity [assessed by heart rate, atrioventricular (AV) conduction time, monophasic action potentials, contractile force, and perfusion rate] from hypothermic @entity63 was studied on isolated perfused @entity35 hearts. The effect of control @entity63 was compared with various cardioplegic protective formulations based on high K+ content. During control hypothermic @entity63 (20 degrees C), the heart activity extinguished only gradually, action potentials were biphasic, AV conduction was extremely prolonged, and contractions were slow and relatively strong. On reperfusion (37 degrees C), the recovery of electrical activity was almost instantaneous and normalized within 2 min, whereas the contractile force remained substantially depressed. In contrast, K+-containing cardioplegic solutions stopped the heart within several cycles. Postarrest recovery was delayed and transitorily associated with severe @entity943 ( @entity713 , repetitive afterdepolarizations and oscillations during elevated plateau, and @entity2224 ). Nevertheless, the action potentials as well as the contractile force virtually normalized in 10-15 min. @entity8162 -containing cardioplegic solutions were ineffective in preventing the onset of postarrest reperfusion @entity943 , whereas addition of @entity594 to the K+-containing cardioplegic solutions largely prevented these @entity943 , and contractile force was further improved by high concentrations of @entity413 . The data indicate that postarrest electrical and mechanical recovery do not recover in parallel. Furthermore, high concentrations of @entity460 antagonist and @entity413 preserve the electrical and mechanical properties of the cardiac muscle during periods of @entity1167 .
