Electrocardiographic predictors of atrial mechanical sensing in patients with leadless VDD pacemakers

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Leadless pacemakers (LP) capable of VDD function are a cornerstone of modern pacemaker therapy reducing complications in elderly patients while enabling atrioventricular synchrony through mechanical sensing of atrial contraction. Because mechanical sensing is less reliable than electrical sensing, the reliability of VDD function in LP varies. We evaluated the p-wave amplitude from patient ECGs as a predictor for successful VDD function in LP. MATERIALS AND METHODS: Consecutive patients undergoing LP implantation capable of VDD function were included in this multi-center retrospective cohort study. As VDD function is mainly dependent on the A4 signal amplitude in the current generation of the device, ECG parameters pre-implantation were evaluated separately and in combination for association with A4 signal amplitude post-implantation. RESULTS: 122 Patients (mean age 81, female 44%, mean BMI 25.9 kg/m2) were included. Main indication for LP implantation was AV-Block (70%). BMI-adjusted P-wave amplitude demonstrated a statistically significant positive correlation with A4 signal amplitude in leads I, II, aVL, aVF, aVR, V1 and V2 (all p<0.05). A p-wave amplitude of at least 0.1mV had a specificity of 72% (95%-CI 50%-89%) for a good A4 signal. A sum of at least 0.2mV of p-wave amplitudes in V1 and aVL predicts a specificity of 83% (95%-CI 67-100%) for a good A4 signal. CONCLUSIONS: P-wave amplitudes in selected ECG leads can predict A4 signal amplitude and therefore the reliability of VDD function in LP. [Figure: see text] [Figure: see text]