PRECONDITIONING DOES NOT ATTENUATE CARDIAC DYSFUNCTION AFTER GLOBAL-ISCHEMIA IN THE GUINEA-PIG

Ischaemic preconditioning reduces infarct size, but the effects on car diac function after global ischaemia are more controversial. Additiona lly, species differences may exist. The present study investigates the effects of preconditioning on cardiac performance in the globally isc haemic. Langendorff-perfused guinea-pig heart. Hearts were stabilized for 25 min, and divided into the following groups: (1) (n = 8) control perfusion for 16 min before 30-min global ischaemia and 30-min reperf usion, (2) (n = 7) two episodes of 3-min ischaemia and 5-min reperfusi on before global ischaemia. (3) (n = 7) 5-min ischaemia and 10-min rep erfusion before ischaemia. (4) (n = 8) control perfusion before 40-min ischaemia arid 30-min reperfusion. (5) (n = 8) Preconditioning as gro up 2 before ischaemia as group 4. (6) (n = 9) Control perfusion before 50-min ischaemia and 30-min reperfusion, (7) (n = 10) Preconditioning as group 2 before ischaemia as group 6. A dose-dependent reduction of left ventricular systolic pressure, and increase of end-diastolic pre ssure was observed during reperfusion after 30-. 40- and 50-min ischae mia. Preconditioning did not influence these changes, nor did it atten uate the incidence of severe reperfusion arrhythmias or reduction of c oronary flow. in conclusion, ischaemic preconditioning does not improv e cardiac function during reperfusion of the globally ischaemic, isola ted guinea-pig heart.