Observations on the action of ergonovine on the coronary circulation and its use in the diagnosis of coronary artery insufficiency

Abstract

The clinical and electrocardiographic findings indicate that ergonovine, intravenously, has a definite action on the coronary circulation. The symptoms produced are typically those of angina pectoris, and the electrocardiograms correspond to the expected picture of coronary insufficiency, 17,18,19 including the pattern observed during positive anoxemia 7,8,9 and exercise tolerance tests, 1,5 and consist mainly of RS-T depression and T-wave inversion. Since ergonovine maleate rarely produced tachycardia, the changes induced were not due to an increase in heart rate. Nitroglycerin is effective in preventing the ergonovine-produced angina and in shortening the duration of the electrocardiographic abnormalities. In view of the small series of patients studied, further investigation is warranted before any final statements can be made as to the general utility of ergonovine maleate as a measure of the functional status of the coronary circulation. Further study is also indicated to determine the minimum dose of ergonovine that will produce electrocardiographic effects without causing the symptoms of angina. Knowledge of the circulatory action of this drug is essential in view of its widespread use in obstetrics. While no untoward reactions were noted in our subjects, caution must be exercised to avoid excessive dosage and to have available for immediate use vasodilator drugs such as amyl nitrite and nitroglycerin.