[Sick sinus syndrome (extrinsic and intrinsic form) during long term observation]

The aim of the study has to be find, on basis of long term follow-up, an independent factors determining of pacemaker implantation in patients with intrinsic and extrinsic form of sick sinus syndrome. The second point was to find an independent risk factors of stroke and another serious complication in this group of patients (specially in paced group). The study group consisted 169 pts with sick sinus syndrome (in all pts abnormal electrophysiological tests--transoesophageal atrial stimulation). The form of sinus node dysfunction (extrinsic or intrinsic) was determined on basis of electrophysiological study after pharmacological denervation of the heart (propranolol and atropine i.v. in doses 0.2 and 0.04 mg/kg body weight respectively). The statistical analysis was performed on all pts (97 men and 72 women 48 +/- 16 yrs old) using Cox's model of proportional hazardous analysing. The follow-up period ranging from 14 to 84 months (mean 49.9 +/- 19). Pacemaker was implanted in 88 pts during observation period. Stroke signs were found in 7 pts including 6 pts after pacemaker implantation. There was 13 death (7 sudden or primary neurological death).

1) independent factors of pacemaker implantation were syncope, age and persistent bradycardia, 2) form of sinus node dysfunction was not an independent factor of this decision, 3) age (older), persistent after pacemaker implantation syncope and registered in transesophageal ecg ventriculo-atrial condition were independent risk factors of stroke in pts with VVI stimulation, 4) despite of pacemaker implantation (VVI mode) many patients have presyncopal or syncope attacks but life comfort in this group was much better then before implantation.