Atenolol versus amlodipine versus isosorbide-5-mononitrate on anginal symptoms in syndrome X.

The effects of a beta blocker (atenolol), a calcium antagonist (amlodipine), and a nitrate (isosorbide-5-mononitrate) on anginal symptoms in 10 patients with syndrome X were assessed in a crossover, double-blind, randomized trial. Only atenolol was found to significantly improve chest pain episodes, suggesting that it should be the preferred drug when starting pharmacologic treatment of patients with syndrome X.