Coronary artery tone assessed by the administration of ergonovine maleate and nitrates

: Angiographic changes caused by administering ergonovine maleate (EM) and nitrates were quantitated in 136 patients without significant coronary artery disease. Percent coronary artery (CA) narrowing was calculated in 67 patients with a negative EM test (Group A) and 69 patients with a positive EM test (Group B) as follows: (Formula; see text) In both groups, coronary artery narrowing before and after EM did not differ among the proximal, middle or distal segments of each coronary artery. The measurements of the right coronary artery were greater than those of the left anterior descending artery (p less than 0.01 after EM, p less than 0.05 before EM), and those of the left main trunk were markedly less than those of the other coronary arteries (p less than 0.01). In both groups, coronary narrowing after EM administration was greater than before administration (p less than 0.01). Initial coronary narrowing in Group B was also greater than in Group A (p less than 0.01), similar to the responses for EM. In 19 patients with coronary artery spasm provoked by EM coronary artery narrowing before and after EM was 37 +/- 12% and 69 +/- 23% for coronary arteries with spasm, and 30 +/- 13% and 42 +/- 16% for those without spasm. Not only after, but also before EM administration, coronary narrowing was greater in the arteries with spasm than in those without spasm (p less than 0.01). Furthermore, the arteries without spasm showed greater sensitivity to EM and nitrates than did the arteries of the control patients.(ABSTRACT TRUNCATED AT 250 WORDS)