Effects of phentolamine and atropine on angina pectoris induced by handgrip test in patients with variant angina

In 19 patients with variant angina, handgrip test as an isometric exercise was performed in 3 conditions on different successive days in the early morning: in the control, after administration of phentolamine (0.3 mg/kg) and after administration of atropine sulfate (0.04 mg/kg). Angina associated with ST-segment elevation on the electrocardiogram was induced in 5 patients (26%) in the control condition, in 14 (74%) after phentolamine and in 5 of 16 (31%) after atropine. All anginal events but 1 occurred after the cessation of the exercise and were not associated with the significant increase of rate-pressure products. These attacks were considered to be due to coronary spasm. The frequency of the induction of angina was significantly higher after phentolamine than in the other 2 conditions (p less than 0.01). It is concluded that the attack can be induced by the handgrip exercise in a sizable number of patients with variant angina, and that the administration of phentolamine increases the incidence of angina induced by handgrip exercise. The mechanism or mechanisms by which coronary spasm is induced by handgrip exercise remains to be elucidated.