theophylline effects in patients with syndrome x

a role of adenosine in pathogenesis of syndrome x has recently been postulated. previous studies suggest that aminophylline (an adenosine receptor blocker) improves exercise tolerance in this disorder. present study was performed to examine the efficacy of theophylline in syndrome x and to determine the incidence of cardiovascular risk factors and clinical, ecg and angiographic findings in these patients. 31 patients were studied. the first 16 patients received theophylline. other 15 cases received placebo. exercise tolerance test was repeated after 1-2 weeks. patients who received theophylline had increase in rate-pressure product at peak exercise and decrease in symptoms during exercise, but stage of st depression, global and peak st depression, exercise tolerance and persistence of st depression more than 3 minutes in recovery and symptoms of patients in general were not significant different. theophylline has a favorable effect on exercise, reduces chest pain and rate-pressure product at peak exercise in patients with syndrome x, but not on other variables of exercise test.