Coronary arterial spasm and Prinzmetal's variant form of angina induced by hyperventilation and Tris-buffer infusion.

Abstract

SUMMARY 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.IT IS INCREASINGLY EVIDENT that coronary arterial spasm plays an important role in the pathogenesis of Prinzmetal's variant form of angina.'5 However, the mechanism by which coronary arterial spasm occurs is unknown.Contraction of vascular smooth muscle depends quantitatively on the presence of calcium ions which are required for the activation of myofibrillar ATPase.6-9 Physiologically, a highly potent calcium antagonistic action is exerted by hydrogen ions which seem to compete with calcium ions for the same active sites both at the transmembrane calcium transport system and at the myofibrillar ATPase.91 Thus, vasoconstriction occurs if calcium ion concentration increases or hydrogen ion concentration decreases, whereas vasodilatation is produced by either calcium deficiency or an increased hydrogen ion concentration.9The present study examines whether coronary arterial spasm and anginal attack could be induced by hyperventilation and Tris-buffer infusion, which decrease hydrogen ion concentration, in patients with Prinzmetal's variant form of angina. Materials and Methods Nine patients with Prinzmetal's variant form of angina were studied. All the patients had recurring attacks of chest pain in association with ST segment elevation in the electrocardiogram more than five times a week at the time of the study. Their age, sex, electrocardiogram at rest and during attack, and coronary arteriograms are shown in table 1. None of the patients had received digitalis or diuretics, and all the medications were stopped at least three days before the study, except nitroglycerin, which was stopped at least two hours before the study.Blood pressure, 12-lead electrocardiogram and arterial blood for pH and gas analysis were taken while patients were supine from 9:00 a.m. to l1:00 a.m. Patients then received a five-minute infusion of Tris-buffer 100 ml (pH 10). Immediately after, vigorous hyperventilation was performed for five minutes under the constant monitoring of blood pressure and electrocardio...

Spasm Provocation Tests Performed under Medical Therapy: A New Approach for Treating Patients with Refractory Coronary Spastic Angina on Emergency Admission

“…Non-invasive methods, such as hyperventilation, cold stress, exercise and mental stress tests are useful for the diagnosing disease and evaluating the effects of medical therapy (15)(16)(17)(18). However, the positive rate on these tests is not very high, with the exception of the hyperventilation test.…”

Effects of diltiazem hydrochloride on pressor and steroidogenic actions of angiotensins and norepinephrine in man.

“…It also has some hypotensive action in dogs (Ishikawa, et al, 1978). DTZ inhibits NE-induced contraction of the aortic strip of the rabbit (Nagao et al, 1978) and pressor actions of All and NE in rats (Sato et al, 1978). In dogs it inhibits renal vasoconstricting action of All whereas it has no effect on that of epinephrine (Yamaguchi et al, 1974).…”

“…1 (Grtin and Fleckenstein, 1972;Fleckenstein et al, 1972). DTZ, one of the Ca-antagonists which was synthesized in Japan (Sato et al, 1971), has been used as a coronary vasodilator for the therapy of coronary arterial spasm (Yasue et al, 1978). It also has some hypotensive action in dogs (Ishikawa, et al, 1978).…”

“…Recently inhibitory effects of diltiazem hydrochloride (DTZ), a Ca-antagonist, on pressor responses to AII and NE were reported in animals (Yamaguchi et al, 1974;Sato et al, 1978;Nagao et al, 1978). However, no data are available regarding the Ca-dependecy of pressor and steroidogenic actions of AII, angiotensin III (AIII) and NE in man.…”

Overview of the Non-Invasive Examinations in Patients with Coronary Spastic Angina

“…Coronary artery spasm is finally diagnosed by a pharmacologic agent, such as acetylcholine or ergonovine, in the cardiac catheterization laboratory [1][2][3]. However, before performing the coronary angiography, it may be prefered by cardiologists to obtain ischemic findings in these patients.…”