Pulmonary circulation and thyroid hormone levels in pacemaker patients with and without atrial fibrillation.

The pulmonary haemodynamics and thyroid hormone level were investigated in 21 patients with EKS-222 (VVI) pacemaker, implanted after successful transvenous electrical endocardial His-bundle fulguration (TEF). Triiodthyronine (T3) and thyroxine (T4) were determined by radioimmunoassay, pulmonary circulation parameters were estimated by means of radiocardiography and radionuclide ventriculography using an Omega 500 gamma-camera and a "Scintron MX" computer system. Patients with atrial fibrillation (AF) during VVI pacing had higher level of T3 and T4 and better pulmonary circulation parameters than those with persistent sinus node activity during paced rhythm.