Ethyl alcohol. Effects on coronary blood flow in man.

The myocardial clearance of rubidium may be obtained by praecordial counting after a single intravenous injection of Rb86Cl.Eight normal men as well as I2 men with coronary heart disease had this determination performed before and 20 minutes after the ingestion of go ml Canadian Club whisky.In the 8 normals, the average increase of the myocardial clearance of rubidium after alcohol was II ml/mn per Ioog myocardium.In II of I2 cases with coronary heart disease, the rate increased after alcohol, the rise rangingfrom 4 to 9I mil/min per Ioo g myocardium.The average change in the group amounted to +33 mllmin per Ioo g myocardium (P1<0.02).The explanation for the large increase in coronary blood flow that alcohol produced in some of our cardiac patients is unknown.Possible mechanisms to explain this finding are presented.Ethyl alcohol has been used in the treatment of angina pectoris ever since its original description by Heberden (I786).Relief of ; ischaemic pain has been frequently described, and though Russek, Naegele, and Regan (I950) as well as Conway (I968) failed to show any improvement in the exercise electro- cardiograms of patients with coronary heart disease, alcohol is still advocated for its bene- ficial therapeutic effects.Controlled experi- mental observations of the effects of alcohol on coronary blood flow, however, are contra- dictory.Thus, Lasker, Sherrod, and Killam (I955) reported a rise in coronary blood flow and a decline in coronary resistance in open- chested dogs after dosages of alcohol greater than 375 mg per kg.Ganz (I963) infused alco- hol at an average dose of 58 mg/kg per min for 20 minutes into IO anaesthetized dogs.