The preventive effect of magnesium on coronary spasm in patients with vasospastic angina.
OBJECTIVE
Previous studies have reported that magnesium (Mg) deficiency is associated with coronary spasm. However, little is known about the preventive effect of Mg on coronary spasm. The present study investigated whether Mg prevents coronary spasm in patients with vasospastic angina (VSA).


METHODS
Effectiveness trial.


METHODS
University medical center.


METHODS
Twenty-two patients with VSA.


METHODS
Coronary spasm was induced with an intracoronary infusion of acetylcholine (Ach). After spontaneous relief of the coronary spasm, Mg sulfate (0.27 mmol/kg body weight) was infused IV over 20 min in 14 patients and isotonic glucose was infused in 8 patients as control subjects. Intracoronary infusion of Ach was then repeated, and the diameter of the coronary arteries was measured quantitatively.


RESULTS
Mg infusion caused coronary artery dilatation at baseline in both the spastic (5. 9 +/- 2.3%) and nonspastic segments (5.5 +/- 1.5%). Mg infusion reduced the severity of chest pain and ST-segment deviations during coronary spasm. After the Mg infusion, the percent change in the diameter of the spastic segments improved from - 62.8 +/- 2.6% to - 43.7 +/- 4.7% during coronary spasm. Overall, 10 of 14 patients (71%) responded favorably to Mg infusion. Isotonic glucose infusion did not elicit changes in chest pain severity, ST-segment deviations, or the diameter of the coronary arteries during spasm.


CONCLUSIONS
Mg infusion produces nonsite-specific basal coronary dilatation and suppresses Ach-induced coronary spasm in patients with VSA.
Teragawa
H
H
First Department of Internal Medicine, Hiroshima University School of Medicine, Hiroshima, Japan. teragawa@mcai.med.hiroshima-u.ac.jp
Kato
M
M
Yamagata
T
T
Matsuura
H
H
Kajiyama
G
G
D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000789:Angina, Unstable / Q000503:physiopathology; D017023:Coronary Angiography; D003329:Coronary Vasospasm / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000517:prevention & control*; D003331:Coronary Vessels / Q000187:drug effects; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D014664:Vasodilation / Q000187:drug effects
D008278:Magnesium Sulfate; D000109:Acetylcholine