Effects of adrenaline, administered early or later after ischaemia, and reperfusion on the isolated rat heart
Objective. To evaluate the effect of adrenaline on cardiac function when given early or later in the reperfusion period. Design. Prospective study. Setting. University laboratory. Participants. Wistar rats. Interventions. Isolated rat hearts were subjected to 45 minutes of normothermic ischaemic arrest. During reperfusion, adrenaline was administered early (2 minutes) or later (12 minutes) after termination of ischaemic arrest in addition to a short (5 minutes) or longer (10 minutes) recovery period before function was resumed. Measurements and results. Aortic and coronary flow, peak systolic pressure and heart rate were determined before arrest, 10 and 15 minutes after termination of ischaemic arrest. Adenosine triphosphate and creatine phosphate levels were also determined after cardioplegic arrest and reperfusion. Results indicate that early administration of adrenaline was not detrimental but that a longer recovery period after arrest resulted in significantly better cardiac function. Conclusion. After ischaemic arrest of the isolated rat heart a longer recovery period resulted in better cardiac function than a shorter period of recovery.