Effect of cardiac arrest on cerebral circulation. An experimental investigation

The effect of 2 to 15 min of cardiac arrest on cerebral circulation was investigated in dogs and Rhesus monkeys. When circulatory arrest lasted longer than 5 minutes, angiographic changes of the no-reflow phenomenon were observed between 3 and 4 h after resuscitation in dogs but not in monkeys. These findings were (1) marked prolongation of the arterial phase in both intracranial and extracranial arteries; followed by (2) occasional evidence of dilatation of the proximal intracranial arteries with non-filling of the distal intracranial arteries; and (3) faint demonstration of the venous phase. Carbon black perfusion results were (1) diffuse lack of perfusion at the arteriolar-capillary level and (2) multifocal areas of filling defects. Regional cortical blood flow measurement in monkeys disclosed a significant decrease in flow starting from 3 h after re-establishment of circulation for those in which longer than 5 min of arrest was induced.