CONTROLLED POSTCARDIOPLEGIA REPERFUSION: MECHANISM FOR ATTENUATION OF REPERFUSION INJURY

Controlled reperfusion and secondary cardioplegia are used to minimize reperfusion injury. The mechanisms for their benefit are incompletely defined and may include attenuation of myocyte sodium uptake. Pigs had 1 hour of cardioplegic arrest followed by reperfusion with blood (control) or warm cardioplegic solution followed by blood (test). Reperfusion injury in the control and test groups was quantified by measuring changes of intramyocyte ion content with atomic absorption spectrometry and by analyzing electrophysiologic recovery from recordings of reperfusion arrhythmias. Control animals had an increase in intramyocyte sodium content at 5 minutes after initiating reperfusion (+20.2 micromol/g dry weight, P