Prompt termination and/or prevention of cold-pressor-stimulus-induced vasoconstriction of different vascular beds by magnesium sulfate in patients with Prinzmetal's angina.

In a group of 15 patients with Prinzmetal's angina, cold-pressor-induced anginal attacks were both promptly terminated and prevented by Mg sulfate. Cold-pressor-induced pulmonary hypertension and Raynaud's phenomenon were successfully prevented. Normalization by MgSO4 of the excessive reactive blood pressure increase in response to the cold stimulus was observed.