Cerebral circulation after cardiac arrest. Angiographic and carbon black perfusion studies.

Cardiac arrest of 2-15 minutes was induced in 14 dogs. When circulatory arrest lasted longer than 5 minutes, abnormal cerebral angiographic findings were seen 3-4 hours after resuscitation, consisting of (a) marked prolongation of the arterial phase in both intracranial and extracranial arteries, and (b) faint (poor) visualization of the venous phase. No significant abnormalities were noted in dogs arrested less than 5 minutes, or in the control group. Carbon black perfusion studies showed multiple focal areas of small patchy and diffuse coarse reperfusion defects at the arteriolar-capillary levels in dogs arrested longer than 5 minutes. A combination of vascular and parenchymal changes during ischemia may be the cause of these findings.