[Effect of intravenous administration of diltiazem on cerebral blood flow and brain function]

The effect of intravenous administration of diltiazem on cerebral circulation and brain function were studied in animals. Diltiazem, at a dose of 150 micrograms/kg BW, was administered intravenously over a period of 5 minutes beginning 30 minutes after ligation of the right brachiocephalic artery in 9 cats in order to investigate its effects in the acute stage of cerebral ischemia. In 5 animals, mean arterial blood pressure was recorded and blood flow in the basilar artery was measured transdurally by use of an ultrasonic Doppler flow-meter. Mean arterial blood pressure began to elevate immediately after ligation of the right brachiocephalic artery, but the degree of elevation was minimal. It began to fall during diltiazem injection and returned to the preadministration value 30 minutes after injection. Basilar artery flow decreased slightly during injection of diltiazem, but began to increase after completion of injection. The increase relative to the preadministration value was 62 +/- 31% 10 minutes after injection, 88 +/- 38% 20 minutes after, and 24 +/- 53% 30 minutes after. The short latency somatosensory evoked potentials (short latency SEP) recorded in the other 2 animals showed no noticeable change either in amplitude or latency during the same procedures. In 1 of 2 animals in which brainstem auditory evoked potentials (BAEP) were monitored, the latency of peak IV increased after ligation of the right brachiocephalic artery, and decreased 20 minutes after injection of diltiazem.(ABSTRACT TRUNCATED AT 250 WORDS)