[Unstable stenocardia: the reaction to ergometrine administration].

Ergometrine test was undertaken on the 1--3d day after hospitalization in 49 patients with unstable angina pectoris. Pain or ECG changes were recorded in 90% of patients. Reactions with the rise of the ST segment and changes of the T wave on ECG were interpreted as "spastic" and were seen in 43% of cases. Myocardial infarction supervened during hospitalization in 19% of patients with "spastic reactions", and in 14.3% of other patients. Selective coronarography was performed in 33 patients. During coronarography the local spasm of one coronary artery supervening always at the site of organic stenosis was seen in 10 patients (30%). Spastic reactions in angina pectoris can be elicited relatively frequently, but nonspecific reactions are possible, with low tolerance of haemodynamic shifts caused by ergometrine. In the initial angina pectoris, immediately preceding myocardial infarction ergometrine may cause no reaction. An increased tendency of atherosclerotic coronaries to spasm plays a definite role in the development of unstable angina pectoris, in a part of patients only (or only in a certain phase of its course). Such reactions are not associated with a considerably increased danger of development of myocardial infarction.