[Significance of autonomic block by drugs for the diagnosis and evaluation of the pathogenesis of the sick sinus syndrome].

Altogether 65 patients with the sinoatrial node weakness syndrome (SANWS) and 48 patients with the heart pain syndrome (control group) were examined for a study of the corrected time of sinoatrial node function recovery (CTSNFR) and the time of sinoatrial conduction (TSAC) before and after medicamentous vegetative blockade (MVB). A considerable increase in CTSNFR and TSAC sensitivity after MVB was noted. In most of the SANWS patients CTSNFR after MVB was increased, TSAC was decreased. Elevated CTSNFR in the SANWS patients was determined by the effect of propranolol and atropine and was noted mainly during atrial stimulation with a high frequency (over 160 imp/min).