CLINICAL EXPERIENCE IN USING PACEMAKERS WITH «AUTOMATIC-CAPTURE» FUNCTION IN ELDERLY PATIENTS

Abstract

Research aim. This study researches the pacemakers with «Automatic-Capture» function and equipped different models leads in elderly patients. Materials and methods. We studied cases of 51 patients (24 men, 27 women). The mean age was 66,4 ± 2,2 years. Patients had conventional indications for cardiac pacing with sinus node dysfunction - 17 (33%), permanent atrial fibrillation with AV - block -26 (51%), progressive atrioventricular block - 8 (16%). Pacemakers with «Automatic-Capture» function controlling effectiveness of each stimulus were implanted: Insignia I AVT DR - 25, Insignia I AVT SR (Guidant) - 26. The Lead passive fixation: Fineline II (Guidant) - 24, Capsure SP novas 5592 (Medtronic) - 15, Stelid II BTF 26D (Sorin group) - 3, ELBI 211-321 (Elestim Cardio) - 1, Membrane 1450 (St. Jude) - 5 active fixation: Flextend (Guidant) - 3. Results. In our study, the pacemakers with Automatic-Capture function correctly measured the thresholds in all cases. Amplitude of R-wave did not reach the required value of 5 mV in two clinical cases. Function did not worked correctly in one case, where the amplitude of the R-wave was 4.9 mV. Тhe amplitude fluctuated during the observation period from 3.5 mV to 4.4 mV in the second case. In these cases, automatic measurement of the stimulation threshold did errors in 5 out of 46 measurements. When the stimulation threshold was about 0.5 V, the pacemaker occasionally changed its value from 1.5 V to 2.7 V. In both cases, the pacemaker system did not work properly, even in Retry mode. These does not consumed more energy from pacemaker battery. In two cases: with paroxysmal atrial fibrillation and the micro dislodgment of the ventricular lead, we observed episodic system functioning in the high voltage safety stimulation mode (Retry mode). Conclusion. The use of the Automatic-Capture function significantly reduced energy consumption in all the leads. In individual cases, an improper measurement of the stimulation threshold is still possible. Paroxysms of tachysystolic atrial fibrillation and microdislocation of electrodes in elderly patients can cause the system to switch to high voltage safety simulation.