Lead stability in patients with permanent left bundle branch pacing

Abstract

Objective \nThe aim of our study was to report the mid-long term lead performance in patients with permanent left bundle branch (LBB) pacing. \n \n \nMethods \nWe enrolled the patients with successful LBB pacing from November 2017 to June 2019 in the Fifth Ward of Department of Cardiology in the First Affiliated Hospital of Nanjing Medical University. Programmed parameters, including R-wave amplitude, pacing threshold, and impedance, were analyzed regularly. Electrocardiograms (ECG) under lead tip and bipolar pacing were routinely recorded. For the patients with changed pacing parameters or ECG morphologies, echocardiogram or cardiac dual-source CT was performed to determine the position of the lead tip. \n \n \nResults \nTotally LBB pacing was successfully performed in 220 patients with 124 males, and a mean age of (68.7±11.9) years. One hundred and sixty-nine patients with baseline and at least one follow-up records were included. Pacing parameters of LBBpacing were unchanged during a mean follow-up of (10.5±5.2) months. There was not significant difference of the mean pacing threshold[ (0.7±0.2) V vs. (0.5±0.1) V, P>0.05]and R-wave amplitude[ (18.1±7.3) mV vs. (15.9±7.4) mV, P>0.05]at 6-month follow-up. No patient of elevated pacing threshold over 1 V was found. Lead protrusion into left ventricular cavity occurred in 3 patients during procedure, and none after the implantation. Four patients had lead dislodgement during procedure and 2 patients were re-implanted LBB pacing leads successfully. One patient had lead dislodgement to the right atrium after the implantation and the pacing lead was positioned at right ventricular apex at one-month follow-up. Lead micro-displacement was observed in 7 patients with changed pacing ECGs but unchanged pacing parameters. Imaging tests confirmed that the pacing leads were still within the ventricular septum. Most of the patients (6/7) were found with lead micro-displacement in one week after the procedure. No lead revision was needed in all 7 patients due to the normal programmed tests. \n \n \nConclusion \nLBB pacing was safe with stable pacing parameters during mid-long term follow-up. Lead micro-displacement should be paid attention when pacing ECG changed but programmed parameters were normal. \n \n \nKey words: \nCardiac pacing, artificial;\xa0Left bundle branch;\xa0Programmed parameters;\xa0Lead mirco-displacement