Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands.
Department of Cardiology, Maastricht University Medical Center, Maastricht, the Netherlands.
Europace. 2018 Jul 1;20(7):1146-1153. doi: 10.1093/europace/eux208.
Left ventricular (LV) fusion pacing appears to be at least as beneficial as biventricular pacing in cardiac resynchronization therapy (CRT). Optimal LV fusion pacing critically requires adjusting the atrioventricular (AV)-delay to the delay between atrial pacing and intrinsic right ventricular (RV) activation (Ap-RV). We explored the use of electrogram (EGM)-based vectorloop (EGMV) derived from EGMs of implanted pacing leads to achieve optimal LV fusion pacing and to compare it with conventional approaches.
During CRT-device implantation, 28 patients were prospectively studied. During atrial-LV pacing (Ap-LVp) at various AV-delays, LV dP/dtmax, 12-lead electrocardiogram (ECG), and unipolar EGMs were recorded. Electrocardiogram and electrogram were used to reconstruct a vectorcardiogram (VCG) and EGMV, respectively, from which the maximum QRS amplitude (QRSampl), was extracted. Ap-RV was determined: (i) conventionally as the longest AV-delay at which QRS morphology was visually unaltered during RV pacing at increasing AV-delays(Ap-RVvis; reference-method); (ii) 70% of delay between atrial pacing and RV sensing (Ap-RVaCRT); and (iii) the delay between atrial pacing and onset of QRS (Ap-QRSonset). In both the EGMV and VCG, the longest AV-delay showing an unaltered QRSampl as compared with Ap-LVp with a short AV-delay, corresponded to Ap-RVvis. In contrast, Ap-QRSonset and Ap-RVaCRT were larger. The Ap-LVp induced increase in LV dP/dtmax was larger at Ap-RVvis, Ap-RVEGMV, and Ap-RVVCG than at Ap-QRSonset (all P < 0.05) and Ap-RVaCRT (P = 0.02, P = 0.13, and P = 0.03, respectively).
In this acute study, it is shown that the EGMV QRSampl can be used to determine optimal and individual CRT-device settings for LV fusion pacing, possibly improving long-term CRT response.
左心室（LV）融合起搏在心脏再同步治疗（CRT）中似乎至少与双心室起搏一样有益。优化 LV 融合起搏需要将房室（AV）延迟精确调整为心房起搏与固有右心室（RV）激活（Ap-RV）之间的延迟。我们探索了使用源自植入式起搏导线电图（EGM）的基于电描记图（EGM）的向量环（EGMV）来实现最佳的 LV 融合起搏，并将其与传统方法进行比较。
在 CRT 设备植入期间，前瞻性研究了 28 名患者。在各种 AV 延迟下进行心房-LV 起搏（Ap-LVp）时，记录 LV dP/dtmax、12 导联心电图（ECG）和单极 EGM。心电图和电描记图分别用于从向量心电图（VCG）和 EGMV 重建向量心电图（VCG）和 EGMV，从中提取最大 QRS 幅度（QRSampl）。Ap-RV 通过以下方法确定：（i）传统方法为在 RV 起搏时，在增加 AV 延迟的情况下，QRS 形态在视觉上保持不变的最长 AV 延迟（Ap-RVvis；参考方法）；（ii）心房起搏与 RV 感知之间 70%的延迟（Ap-RVaCRT）；以及（iii）心房起搏与 QRS 起始之间的延迟（Ap-QRSonset）。在 EGMV 和 VCG 中，与 Ap-LVp 相比，具有较短 AV 延迟的最长 AV 延迟显示 QRSampl 保持不变，对应于 Ap-RVvis。相比之下，Ap-QRSonset 和 Ap-RVaCRT 更大。Ap-LVp 诱导的 LV dP/dtmax 增加在 Ap-RVvis、Ap-RVEGMV 和 Ap-RVVCG 时大于 Ap-QRSonset（均 P<0.05）和 Ap-RVaCRT（P=0.02、P=0.13 和 P=0.03）。
在这项急性研究中，表明 EGMV QRSampl 可用于确定用于 LV 融合起搏的最佳和个体化 CRT 设备设置，可能改善长期 CRT 反应。
