European Heart Journal: Case Reports | 2019
The unstable pacing thresholds of the leadless transcatheter pacemaker affected by body positions in subacute phase after implant
Abstract
Abstract Background If the threshold at implant of leadless transcatheter pacemakers (LTPs) is less than 2.0\u2009V, pacing thresholds reportedly decrease significantly by 1\u2009month and maintain an optimal value of less than 1.0\u2009V by 6\u2009months. Case summary We report a case series of two patients with unstable pacing thresholds of the LTPs in the subacute phase after implant. The first patient (77-year-old man) was implanted an LTP for sick sinus syndrome. At that time of implant, the pacing threshold was 0.9\u2009V at 0.24\u2009ms. At 1\u2009week and 1\u2009month later, the threshold had increased to more than 2.0\u2009V at 0.24\u2009ms. We investigated the trend data for the week and found variations in the threshold. The second patient (81-year-old man) was implanted an LTP for bradycardia and atrial fibrillation. The pacing threshold at implantation was 0.63\u2009V at 0.24\u2009ms. One week later, the threshold had increased in supine position and decreased in sitting position. The trend data for the week were fluctuating greatly. Discussion The pacing threshold may increase to more than 2.0\u2009V with significant fluctuation on assessment at 1\u2009week and 1\u2009month after implantation in association with changes in body position, even though we confirmed a stable threshold at implant. If an increased threshold is observed, it is necessary to check the trend data and threshold in each body position.