The prognosis of
spastic angina is difficult to determine. The object of this study was to try to evaluate the prognosis of coronary
spasm on the results of provocative,
ergometrine testing. Out of 708 patients with angiographically normal or near-normal coronary arteries undergoing the
ergometrine test for assessment of
chest pain, 78 patients with positive results were retained for study. The threshold of
spasm was established in every case: this was defined as the quantity of
ergometrine per kilogramme
body weight required to provoke
spasm. The values ranged from 1 to 12.5 micrograms/kg (average 7.58 micrograms/kg +/- 3.84). The reproducibility of the
ergometrine test appeared to be very satisfactory. In the short term, only 4 out of 32 tests became negative. The test remained positive in 28 cases and the mean value of the threshold of
spasm did not change significantly (5.64 +/- 3.27 to 5.52 +/- 3.18 micrograms/kg). In the long term only 2 out of 18 tests became negative. The test remained positive in 16 cases and the mean value of the threshold of
spasm did not change significantly (5.68 +/- 2.96 to 6.58 +/- 3.11 micrograms/kg). The
ergometrine test with a reference threshold of positivity of 5 micrograms/kg is doubly useful: this threshold value helps predict a good response to
calcium inhibitor drugs: the threshold of
spasm was less than this value in 6 of the 41 patients whose tests became negative after
diltiazem therapy, and in 12 of 14 patients in whom the test remained positive (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)