Autonomic nervous system driven resynchronization therapy using left ventricular only pacing with electrocardiographic optimization. A new paradigm. 9+ month follow-up of dual chamber systems

Abstract Background LV-only (LVo) CRT was recognized in the 2013 ESC guidelines [1] as non-inferior to biventricular (biV) CRT in patients with left bundle branch block (LBBB), good atrio-right ventricular conduction (A-RV), sinus rhythm. To improve over biV, an optimal atrioventricular delay (AVD) is needed. Such an LVo has been discussed the past few years [2]. It is an LVo with electrocardiographic optimization that allows the Autonomic Nervous System (ANS) to optimize the A-RV. Objective Present the results of ≥9 months of follow-up (FU) and compare the results with leading CRT alternatives. Methods Since the RV electrode is not needed in LVo, a dual chamber CRT (dcCRT) consisting of a dual chamber pacemaker with atrial and LV leads is used. Left ventricular ejection fractions (LVEF) computed using the biplane Simpson method are reported in FUs. For comparison, we chose the recent results of Zhu [3] with left bundle branch area pacing (LBBAp yielding LBBp and LVSp) and biV. Results The LVEFs are presented in the attached graph. The orange bars on top are used to report the 100 day LVEF when the patient missed the 9 month FU or there is a slight LVEF decline at this FU. Else they are burgundy bars. The mean 9 month LVEF increased +21.2% (26.4% to 46.7%). The best LVEF at 9 months is 74%, from 20% at implant (Δ=54%!). Adverse weather significantly reduced the number of FUs at 14 months, so the final (max) LVEF is shown as the upper dotted red line with 7 increases over the 9 month data. LBBAp is a promising CRT alternative. The latest results by Zhu, published in August 2024, are summarized on top of the Table. Below are the results with our ANS driven LVo LVEFs at 100 days, 9 months and 14+ months. The LVEF changes in the left half of the table shows clear superiority of the LVo method. The right half of the table shows the mean LVEF. Even with an older population and lower implant LVEFs (sicker patients), the improvement with the LVo method is superior with greater LVEF changes starting at 100 days than LBBAp and biV! Conclusions Our CRT LVo pacing is used to enable ANS to directly control the synchrony of the 2 ventricles by adjusting the A-RV delay to meet hemodynamic demands against a fixed delay LV pace. This is a paradigm shift from the traditional device driven synchrony in biV. At each FU, the A-RV delay and the LVp delay are measured and the AVD is adjusted (while the patient is at rest) for an early LVp, allowing the ANS to shorten A-RV to meet hemodynamic demand when the patient exercises (see [4]). Our results are superior to Zhu's for LBBAp and biV. Our results were obtained with dcCRT devices. The results are applicable to existing triple chamber CRT device (CRT-P/-D) with expected improved results thanks to the greater flexibility in choosing the LV pacing vector (s) and it is a major CRT paradigm shift in patients with LBBB, good A-RV conduction and sinus rhythm… the future of CRT using current devices!LVEF @ 9+ months  LVEF comparisons