Does hyperventilation plus Tris-buffer infusion induce coronary arterial spasm in patients with Prinzmetal's variant angina, and does diltiazem suppress these reactions?
Hyperventilation combined with Tris-buffer infusion reliably provokes coronary artery spasm in patients with Prinzmetal's variant angina, an effect that can be prevented by prophylactic administration of diltiazem.
Vigorous hyperventilation was induced for five minutes immediately after a five-minute infusion of 100 ml of Tris-buffer (pH 10) in nine patients with Prinzmetal's variant angina. In eight of the patients, chest pain with ischemic changes in the electrocardiogram occurred during this procedure or within five minutes after it ended. Coronary arterial spasm appeared after the procedure and disappeared after the administration of nitroglycerin in all four patients in whom coronary cinearteriography was performed. This was evident both before and after the procedure and after sublingual administration of nitroglycerin (0.6 mg). The oral administration of 90 mg of diltiazem, a calcium antagonistic drug, two hours before, completely suppressed the attack induced by the procedure in all of the five patients who received this drug. We conclude that hyperventilation plus Tris-buffer infusion induces coronary arterial spasm and anginal attack in patients with Prinzmetal's variant angina and that diltiazem suppresses these reactions.
Yasue et al. (Sat,) studied this question.