Blocking Effect of Ethyl Chloride Spray on Cardiac Pain Induced by Ergonovine.

Summary Thirty-six tests were carried out on 7 patients with effort angina but a normal resting electrocardiogram, in whom intravenous injection or ergonovine (0.1 to 0.4 mg) induced angina and electrocardiographic changes. Nitroglycerin, 0.4 or 0.6 mg given sublingually just before ergonovine, prevented pain and electrocardiographic changes in most patients. When angina had been induced by ergonovine and ethyl chloride spray was applied to pain areas of chest, shoulders, arms or neck (reference zone of cardiac pain in each patient), pain was uniformly relieved. Relief of ergonovine angina by ethyl chloride spray required less time than by nitroglycerin. When ethyl chloride spray was applied to pain areas just before ergonovine was injected, pain failed to occur in the majority, and the onset of pain was delayed in the remaining patients. In combination with ethyl chloride spray, ergonovine caused depression of the S-T segment even in the absence of pain. These results afford additional evidence of the previously reported effectiveness of ethyl chloride spray for relief of the somatic component of cardiac pain.