Effect of diazepam on myocardial blood flow of patients with and without coronary artery disease.

Myocardial blood flow was measured by the 133Xe clearance method in 6 patients with radiologically confirmed disease of the coronary arteries and in 4 patients with normal arteries. The myocardial bloodflow was measured 5 minutes after intravenous diazepam OI mg/kg body weight. There was an increase in myocardial bloodflow in all cases. Patients with normal coronary arteries showed an average increase of 22.5 per cent over control levels while patients with diseased coronary arteries showed a 73 per cent average increase. Both figures were highly significant statistically. Possible mechanisms and implications of these findings are discussed.