Department of Cardiology and Pediatric Cardiology, Oslo University Hospital, Oslo, Norway
Department of Cardiology, Oslo University Hospital, Oslo, Norway.
Open Heart. 2021 May;8(1). doi: 10.1136/openhrt-2021-001615.
We designed this study to assess the acute effects of different fusion strategies and left ventricular (LV) pre-excitation/post-excitation on LV dP/dt and QRS duration (QRSd).
We measured LV dP/dt and QRSd in 19 patients having cardiac resynchronisation therapy (CRT). Two groups of biventricular pacing were compared: pacing the left ventricle (LV) with FUSION with intrinsic right ventricle (RV) activation (FUSION), and pacing the LV and RV with NO FUSION with intrinsic RV activation. In the NO FUSION group, the RV was paced before the expected QRS onset. A quadripolar LV lead enabled distal, proximal and multipoint pacing (MPP). The LV was stimulated relative in time to either RV pace or QRS-onset in four pre-excitation/post-excitation classes (PCs). We analysed the interactions of two groups (FUSION/NO FUSION) with three different electrode configurations, each paced with four different degrees of LV pre-excitation (PC1-4) in a statistical model.
LV dP/dt was higher with NO FUSION than with FUSION (769±46 mm Hg/s vs 746±46 mm Hg/s, p<0.01), while there was no difference in QRSd (NO FUSION 156±2 ms and FUSION 155±2 ms). LV dP/dt and QRSd increased with LV pre-excitation compared with pacing timed to QRS/RV pace-onset regardless of electrode configuration. Overall, pacing LV close to QRS-onset (FUSION) with MPP shortened QRSd the most, while LV dP/dt increased the most with LV pre-excitation.
We show how a beneficial change in QRSd dissociates from the haemodynamic change in LV dP/dt with different biventricular pacing strategies. In this study, LV pre-excitation was the main determinant of LV dP/dt, while QRSd shortens with optimal resynchronisation.
我们设计本研究旨在评估不同融合策略和左心室（LV）预激/后激对 LV dP/dt 和 QRS 持续时间（QRSd）的急性影响。
我们测量了 19 例接受心脏再同步治疗（CRT）的患者的 LV dP/dt 和 QRSd。比较了两组双心室起搏：LV 通过融合内在右心室（RV）激活（FUSION）起搏（FUSION），LV 和 RV 通过无融合内在 RV 激活起搏（NO FUSION）。在 NO FUSION 组中，RV 在预期 QRS 起始之前起搏。四极 LV 导联能够进行远端、近端和多点起搏（MPP）。LV 相对于 RV 起搏或 QRS 起始的时间在四个预激/后激类（PC）中进行刺激。我们在统计模型中分析了两组（FUSION/NO FUSION）与三种不同电极配置之间的相互作用，每种配置都以四个不同程度的 LV 预激（PC1-4）起搏。
与 FUSION 相比，NO FUSION 时 LV dP/dt 更高（769±46mmHg/s 比 746±46mmHg/s，p<0.01），而 QRSd 无差异（NO FUSION 156±2ms 和 FUSION 155±2ms）。与起搏时间到 QRS/RV 起搏起始相比，无论电极配置如何，LV 预激时 LV dP/dt 和 QRSd 均增加。总体而言，与 MPP 起搏时接近 QRS 起始（FUSION）的 LV 起搏可最大程度缩短 QRSd，而 LV 预激时 LV dP/dt 增加最多。
我们展示了不同双心室起搏策略如何使 QRSd 的有益变化与 LV dP/dt 的血液动力学变化分离。在本研究中，LV 预激是 LV dP/dt 的主要决定因素，而 QRSd 随着最佳再同步而缩短。
