Methergin testing with angiographically normal coronary arteries.

To evaluate the incidence of spasm in patients with angiographically normal coronary arteries or with stenosis ≤50%, methergin testing was done consecutively in 1,200 patients (742 men and 458 women). The methergin test was performed 850 times during coronary angiography and 350 times after it. The test was globally positive in 11 % (127 of 1,200 patients), positive in 7% among 921 patients presenting with atypical chest pain, 13% of 31 patients with effort angina, 54% of 54 with angina at rest, 57% of 53 with Prinzmetal's angina, 3% of 59 with acute myocardial infarction and 1% of 82 miscellaneous patients without chest pain. Another test was done in 291 patients after blockade of the cardiac autonomous nervous system with 0.04 mg/kg of atropine and 2 mg/kg of labetolol. The frequency of positive results in the methergin test increased after blockade from 8 to 19% (p < 0.01). The increase of positive results was especially obvious among patients with atypical chest pain (from 6 to 14%). Thus, frequency of spasm in these patients with normal coronary arteries or without significative lesions was 11%. This incidence was influenced by the composition of the patient population and increased with blockade of the cardiac autonomous nervous system.