QTC INTERVAL DURATION CLASS AND STIMULATION PARAMETERS IN PATIENCE DURING FIRST SIX MONTHS AFTER PACEMAKER

97 patients (55 men and 42 women) with implanted pacemakers (PM) in DDD/DDDR, VVI/VVIR and CRT modes were investigated. Pacing mode, location of the right ventricular (RV) and left ventricular (LV) electrode, percentage of the right atrium (RA), RV and LV stimulation, percentage of atrial flutter (AFl) and atrial fibrillation (AF), percentage of ventricular tachycardia (VT), base frequency of stimulation, RV and LV electrode impedance, RV and LV electrode stimulus amplitude and duration, RV electrode sensitivity, R-waves sensing, stimulated and detected AV-delay, interventricular delay, the minimum refractory period were evaluated in acute postoperative period (3-5 days) and six months after pacemaker implantation. Patients were divided into classes 1 (normal QTc (320-440 ms)) - 41 (42 %) of the patients) and class 2 (long QTc (> 440 ms)) - 56 (58 %) patients) of QTc interval duration. For data processing were used standard statistical procedures by Microsoft Excel. QTc interval prolongation is most often observed in patients with VVI/VVIR stimulation, normal QTc interval duration ? in patients with CRT. The same part of normal and extended QTc interval duration is observed in patients with DDD/DDDR stimulation. Prolonged QTc interval duration is associated with more frequent RV electrode implantation in heart apex, higher percentage of AFl and AF, LV electrode impedance, RV and LV electrodes stimulus amplitude, detected and stimulated AV-delays, minimum refractory period in first six months after PM implantation. Patients with increased QTc interval duration after PM implantation require more intensive monitoring of stimulation parameters and enhancing medication.