P-wave detection performance of the BioMonitor III, Confirm Rx and Reveal Linq implantable loop recorders.

INTRODUCTION:Rhythm interpretation of EGMs recorded by implantable loop recorders (ILRs) is facilitated in cases when p-waves are visible. The three most commonly used ILRs (BioMonitor III, Confirm RX and Reveal Linq) vary in size, electrode placement and filter algorithms. Therefore, p-wave visibility and amplitude on EGM may vary according to the implanted device. MATERIAL AND METHODS:Consecutive patients were included after ILR implantation. P-wave visibility and amplitude were evaluated in sinus rhythm on 30-s EGMs with standard resolution (25 mm/mV for Biotronik and St. Jude, 30 mm/mV for Medtronic) and after maximum magnification. Additionally, baseline characteristics and p-wave amplitude in lead II on the surface-ECG were documented. RESULTS:148 patients with either BioMonitor III (n = 48), Confirm Rx (n = 51) or Reveal Linq (n = 49) ILRs were included. With standard resolution, p-waves were visible in 40 patients (83%) implanted with BioMonitor III, 36 patients (71%) with Confirm Rx and in 35 patients (71%) with Reveal Linq ILRs (p = 0.267). After maximum magnification, p-waves could not be identified in 6 patients with Confirm Rx ILR (12%) and 1 patient in both BioMonitor III and Reveal Linq ILR (2%; p = 0.051). The Biomonitor III showed higher p-wave amplitudes compared to the Confirm Rx (0.050 mV (0.040-0.070) vs. 0.030 mV (0.020-0.040); p < 0.001) and the Reveal Linq ILR (0.050 mV (0.040-0.070) vs. 0.030 mV (0.020-0.040); p < 0.001). CONCLUSION:P-wave amplitudes were higher in patients with Biomonitor III. This did not lead to higher p-wave visibility compared to the Confirm RX ILR or the Reveal Linq ILR.