Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine.
Int Heart J. 2022;63(2):241-246. doi: 10.1536/ihj.21-711.
There are no studies examining interventricular (VV) delay optimization by an electrical cardiometry method in relation to subsequent cardiac function in cardiac resynchronization therapy (CRT) -implanted patients. This study aimed to compare the VV delay in CRT-implanted patients by the dp/dt and electrical cardiometry and to examine the optimization of VV delay and improvement of cardiac function. We examined 19 consecutive CRT-implanted patients. The protocol included biventricular stimulation with either simultaneous or sequential pacing, and we evaluated systolic volume (SV) using an electrical cardiometry and the dp/dt of the left ventricle. The optimal VV delay was determined by the maximum SV using the electrical cardiometry. Two groups were defined, those whose increase in SV was at or above the median and those whose SV increase was below the median; changes in left ventricular ejection fraction (LVEF). The correlation between the VV delay optimized by the electrical cardiometry and dp/dt methods was high (R = 0.61, P = 0.006). Compared to the baseline SV (43.4 mL), the SV increased to 47.8 mL with simultaneous biventricular pacing (versus baseline P = 0.008) and further increased to 49.8 mL with optimized VV delay (versus simultaneous biventricular pacing P = 0.020). LVEF after 6 months significantly improved in the above-median SV increase group (37.6 versus 28.2%, P = 0.041), but not in the below-median SV increase group (26.5 versus 26.5%, P = 0.985). In conclusion, the optimal VV delay by electrical cardiometry method was almost concordant with that by the dp/dt method. Cardiac function significantly improved in the group with the above-median SV increase.
目前尚无研究通过电心计量法检查心室间（VV）延迟优化与心脏再同步治疗（CRT）植入患者随后的心脏功能之间的关系。本研究旨在比较 CRT 植入患者通过 dp/dt 和电心计量法测量的 VV 延迟，并检查 VV 延迟的优化和心脏功能的改善。我们检查了 19 例连续的 CRT 植入患者。该方案包括双心室刺激，采用同步或顺序起搏，并使用电心计量法评估收缩期容量（SV）和左心室 dp/dt。通过电心计量法确定最大 SV 来确定最佳 VV 延迟。定义了两组，SV 增加幅度等于或高于中位数的组和 SV 增加幅度低于中位数的组；左心室射血分数（LVEF）的变化。电心计量法和 dp/dt 方法优化的 VV 延迟之间具有很高的相关性（R = 0.61，P = 0.006）。与基线 SV（43.4 mL）相比，同步双心室起搏时 SV 增加至 47.8 mL（与基线相比，P = 0.008），并通过优化 VV 延迟进一步增加至 49.8 mL（与同步双心室起搏相比，P = 0.020）。在 SV 增加幅度高于中位数的组中，6 个月后 LVEF 显著改善（37.6 对 28.2%，P = 0.041），而在 SV 增加幅度低于中位数的组中没有改善（26.5 对 26.5%，P = 0.985）。总之，电心计量法的最佳 VV 延迟与 dp/dt 方法几乎一致。SV 增加幅度高于中位数的组中，心脏功能显著改善。
