Study objectives: This study was performed to compare
the results of accelerated exercise following mild hyperventilation and
a standard acetylcholine (ACh) test for the induction of coronary
artery spasm in patients with drug-induced coronary artery
Methods and results: The subjects were 74
patients with angiographically confirmed coronary artery spasm who were
examined using accelerated exercise (ie, exercise that
was accelerated every minute according to the protocol of Bruce and
Horsten) following mild hyperventilation and who were not receiving any
medication. ACh was injected in incremental doses of 20 μg and
50 μg into the right coronary artery and incremental doses of 20μ
g, 50 μg, and 100 μg into the left coronary artery. Positive
coronary spasm was defined as ≥ 99% luminal narrowing. Accelerated
exercise following a mild hyperventilation test was as useful for
detecting evidence of ischemia as was an ACh test (48 patients[
64.9%] vs 49 patients [66.2%], respectively; not significant).
No difference was observed between ischemic changes on ECG as a result
of the newly combined method and the occurrence of ACh-induced spasm.
ACh-induced coronary vasospasm occurred in 61 patients (82.4%). In the
remaining 13 patients, intracoronary administration of ergonovine
provoked coronary spasms. No serious irreversible complications were
detected as a result of this newly combined method.
Conclusions: The effectiveness of our newly combined
procedure is equivalent to that of an ACh test to diagnose patients
with coronary artery spasm.