Effect of Heparin in Cases of Coronary Insufficiency

In 1949 Gilbert and Nalefski¹suggested that the favorable results observed from the use of anticoagulant drugs in cases of acute myocardial infarction and angina pectoris may be primarily the result of an increase in coronary blood flow. After this report we attempted to study the effects of heparin and bishydroxycoumarin (dicumarol®) on the electrocardiographic response to standard exercise (Master two-step test)²in several patients with coronary heart disease. The negative results obtained in four carefully selected cases discouraged an extensive study at that time. Our interest was renewed recently, however, when Graham and associates³reported marked relief of symptoms in 55 of 59 patients with angina pectoris who had received weekly or biweekly injections of 50 to 100 mg. of heparin. The therapeutic response in these cases was judged from the frequency of anginal attacks and the requirements for glyceryl trinitrate. It was stated that relief