Intravenous nitroglycerin in experimental cerebral vasospasm. A preliminary report.

Cerebral arteriospasm is a common complication of subarachnoid hemorrhage and is responsible for much of the brain damage which accompanies it. No pharmacologic agent has been found which regularly alleviates arteriospasm. We have evaluated the effect of continuous intravenous nitroglycerin infusion on the diameter of the basilar artery in dogs with cerebral vasospasm experimentally induced by subarachnoid blood injection. In 6 consecutive dogs, 10 minutes after beginning intravenous nitroglycerin at 100 microgram/min and at other times during 120 minutes of infusion, the diameter of the basilar artery had increased from 75 +/- 2% of control value to 114 +/- 2% of control value (p less than 0.001). In all 6 dogs, the basilar artery diameter during infusion was greater than the control value prior to creating subarachnoid hemorrhage. Intravenous nitroglycerin caused only a moderate (8%) decrease in blood pressure. Further investigation of the effects of nitroglycerin on cerebral vasospasm is warranted.