[Sinus node in patients with atrioventricular and interventricular blocks. Electrophysiologic evaluation]

To assess the function of the sino-atrial node, electrophysiological study with pharmacological autonomic blockade was performed in 3 groups of patients: group I with a-v III zero or II zero type 2 heart block, group II with bifascicular interventricular blocks and group III-controls. Sino-atrial node electrogram was recorded in 81% of patients. Obtained results show, that sino-atrial node dysfunction is uncommon in patients with atrioventricular or interventricular blocks (8.6% and 15% respectively). Electrophysiological assessment of sino-atrial node function seems to be important in the consideration of patients with a-v or interventricular blocks for appropriate type of permanent pacing.