[Clinical aspects of the sick sinus syndrome].

Clinico-electrocardiographic studies were carried out in 74 patients with the sick sinus syndrome. The functional tests were used to evaluate the condition of the sinoauricular node (with physical exercise, and dosaged compression of the sinocarotid area). Five variants of the clinical course of the sick sinus syndrome have been distinguished: latent; manifested; the syndrome of bradycardia-tachycardia; the syndrome of sinus bradycardia-auricular bradyfibrillation; constant auricular fibrillation refractor to the treatment including electro-impulse therapy. The functional tests have revealed more pronounced shifts in the P--P interval of patients with the sick sinus syndrome as compared to those in healthy subjects.