Search

The effects of ethanol on blood flow in the coronary arteries, the major blood vessels supplying the heart, and the dimensions of the coronary arteries were examined in 29 patients with coronary artery disease and six normal subjects. Blood flow was measured in the coronary sinus, a large vein that drains coronary arteries, before and during a 15- to 30-minute infusion of dextrose, or sugar, into the hearts of 15 subjects and an infusion of 5 percent ethanol in dextrose solution in 20 subjects. In subjects receiving dextrose, heart rate, arterial pressure, and coronary sinus blood flow were unchanged. In subjects receiving ethanol, coronary sinus flow increased about 27 percent, and resistance in the coronary blood vessels to flow decreased 17 percent. In the ethanol group, there were also changes in the oxygen content in the coronary artery sinus and artery, but no changes in the coronary artery dimensions. The results show that ethanol increases coronary blood flow and decreases resistance without causing any changes in dimensions, suggesting that the effects of ethanol result from dilation of the small blood vessels called arterioles, which cause resistance to flow. (Consumer Summary produced by Reliance Medical Information, Inc.)