RESPONSES TO HEAD-UP TILT TEST IN VASOVAGAL SYNCOPE AFTER ATENOLOL TREATMENT

摘要

This Study was designed to establish the efficacy of atenolol in follow-up Head-up tilt test (HUT) in patients with a positive response in the baseline tilt test. Atenolol is proposed to prevent vasovagal syncope by blocking the initial increase in adrenergic tone. There is no definitive well-controlled study of the efficacy of beta-blockers in patients with vasovagal syncope.Twenty-two patients (13 women, 9 men: mean age 41 +- 18 years) with a history of syncope and a positive HUT were included. The patients were treated with atenolol (50 mg) over a mean follow-up period of 2 +- 4 months and the follow-up HUT was performed. In the follow-up HUT, 17 patients showed either a negative response or increased time before the occurrence of syncope. The patients with tachycardia during head up tilt test showed more favorable response to the follow-up HUT after treatment with atenolol than the patients without tachycardia(p=0.023). The frequency of syncope in patients with improvement were 1.9 +- 1.0 before treatment with atenoJol(p=0.001). The occurrence of tachycardia during head up tilt in the baseline study and the frequency of syncope are useful parameters in predicting of the efficacy with atenolol for preventing vasovagal syncope.