Dual Chamber Rate Responsive Pacing System Driven by Contractility: Final Assessment After 1-Year Follow-up

The aim of this study was to assess the long-term performance of a new dual chamber rate responsive pacing system based on the dynamic measurement of the peak endocardial acceleration (PEA) index of cardiac contractility. Seventy patients who participated in the Multicenter European Clinical Evaluation were studied 1 year after implantation by continuously recording the PEA and the heart rate (HR) during exercise stress testing and during 24 hours of usual activities. A complete examination of standard parameters was also performed to assess the pacing/sensing lead characteristics. Statistical comparisons were performed with the data recorded with the same protocol at 1 month after implant for each patient. A linear correlation coefficient was calculated between PEA and sinus rate when the patient showed predominant atrial tracked rhythm. There were no significant differences between PEA values measured at 1 month and 1 year (PEA = 0.41 +/- 0.26 g vs 0.45 +/- 0.29 g at rest and PEA = 1.63 +/- 0.77 g vs 1.72 +/- 0.83 g during peak exercise). The correlation coefficient remained stable (0.67 +/- 0.15 vs 0.65 +/- 0.14 during daily life and 0.74 +/- 0.14 vs 0.77 +/- 0.11 during exercise). The PEA signal detected by the sensor was reliable and stable. No long-term complications or adverse effects were observed, and the lead performance was comparable to that of a standard lead.