Comparison of P wave durations as assessed with the bipolar and unipolar atrial intracardiac electrograms: Applicability to QuickOpt™

Studies have shown that inter-atrial conduction time (IACT) can be used to estimate optimal PV delays. QuickOpt utilizes the atrial EGM (AEGM) and measures P-wave duration (PW) to estimate the IACT. This study compares PW between bipolar (Bi) and unipolar (Uni) AEGMs in patients with either a pacemaker (PP) or a CRT-D pulse generator. Bipolar (Bi) and Unipolar (Uni) AEGMs were obtained from 42 PP and 18 CRT-D pts. In the PP, PWs associated with Bi and Uni AEGMs were close (114plusmn19 ms vs. 110plusmn20 ms). Intra-patient difference was 3.9plusmn8.7 ms, and the 95% confidence interval for the difference was (1.2, 6.6). With CRT-D, PWs were 79plusmn18.4 ms and 81plusmn14 ms for Bi and Uni sensing and the intra-patient difference was -1.2plusmn14.9 ms. In 18 PP, the difference between ECG and either bipolar or unipolar PW was 4.8plusmn17.8 ms and 0.9 ms plusmn 15.5 ms respectively. PWs were similar between unipolar AEGMs, bipolar AEGMs, and surface ECG.