Sequential spasm provocation tests might overcome a limitation of the standard spasm provocation tests.

OBJECTIVE

We examined the clinical usefulness of sequential spasm provocation tests as follows: first, acetylcholine (ACh) test, second, ergonovine (ER) test, and finally, the ACh test following the ER test.

PATIENTS AND METHODS

We performed the ACh and ER tests in 461 patients (294 men, 64.4±11.3 years of age) during a 23-year period. In addition, we administered an intracoronary injection of ACh after the ER tests in 240 patients. First, ACh [right coronary artery (RCA): 20/50/(80) μg, left coronary artery (LCA): 20/50/100/(200) μg] was administered incrementally over 20 s. Second, ER (RCA: 40 μg, LCA: 64 μg) was administered over 2-4 min. If a provoked spasm did not occur, we administered an intracoronary injection of ACh (50/80 μg into the RCA and 100/200 μg into the LCA) just after the ER tests. A positive spasm was defined as more than 99% transient luminal narrowing.

RESULTS

A positive spasm was observed in 221 (47.9%) patients including 181 ACh-positive (39.3%) and 119 ER-positive (25.8%) patients by the ACh or ER tests. In the 240 patients with a negative spasm in the ACh and ER tests, 48 (10.4%) patients developed provoked spasms on adding ACh after the ER test. The distributions of various cardiac disorders and provoked spasm vessels were similar among the three positive groups. Focal spasm was frequently observed in the ER-positive group, whereas diffuse spasm was frequently obtained in the ACh-positive group and by adding ACh after ER in the positive group. No major complications were recognized during the sequential spasm provocation tests.

CONCLUSION

Sequential spasm provocation tests might overcome a limitation of standard spasm provocation tests.