Relation of platelets to catecholamine induced myocardial injury.

To test the thesis that myocardial injury, induced by catecholamines, is ischaemic in origin due to platelet accumulation in the coronary microvasculature, sustained left intracoronary and systemic infusion of catecholamines in toxic dosage was given to dogs previously infused with autologous 51Cr-labelled platelets. Subsequent determination of tissue radioactivity and electrolytes, as well as electronmicrography, indicated that the induced myocardial injury was not related to microvascular occlusion by platelets.