Brignole Michele, Oddone Daniele, Maggi Roberto, Lupi Gabriele, Bollini Roberto, Corallo Serena, Robotti Stefano, Solano Alberto, Donateo Paolo, Croci Francesco
Arrhythmologic Centre, Department of Cardiology, Ospedali del Tigullio, Via don Bobbio, 16033 Lavagna, Italy.
Europace. 2008 Apr;10(4):489-95. doi: 10.1093/europace/eun059. Epub 2008 Mar 11.
The prerequisite and the rationale for the benefit of cardiac resynchronization therapy (CRT) is that it is able to resynchronize left ventricular (LV) walls that have a delayed activation.
In 69 consecutive patients who underwent biventricular (BIV) pacemaker implantation, we assessed the magnitude of intraventricular resynchronization achieved by means of simultaneous (BIV 0) and sequential BIV pacing (with an individually optimized VV interval value among +80 ms and -80 ms) using pulsed-wave tissue Doppler imaging techniques and in particular the measurement of the intra-LV electromechanical delay. The intra-LV delay was defined as the difference between the longest and the shortest activation time in the six basal segments of the LV. An abnormal intra-LV delay was defined as a value >41 ms. The intra-LV delay was 63 +/- 28 ms baseline, decreased to 44 +/- 26 ms with BIV 0 and to 26 +/- 15 ms with optimized BIV (P = 0.001). BIV 0 determined the shortest delay in 28 (41%) patients (23 +/- 12 ms). In 41 (59%) patients, a better resynchronization was achieved with optimized VV intervals (LV first in 32 and RV first in 5) or single-chamber pacing (LV in 3 and RV in 1). With BIV 0, the intra-LV delay remained abnormal in 41% and was longer than baseline in 30% of patients compared with 9 and 12% with optimized BIV, respectively (P = 0.001).
A sub-optimal resynchronization is achieved with simultaneous BIV pacing in most patients. A tailored programming of the relative contribution of RV and LV pacing forms the prerequisite for improving CRT results.
心脏再同步治疗（CRT）获益的前提条件及基本原理是其能够使激活延迟的左心室（LV）壁实现再同步。
在连续69例接受双心室（BIV）起搏器植入的患者中，我们采用脉冲波组织多普勒成像技术，特别是通过测量左心室内机电延迟，评估了通过同步（BIV 0）和顺序BIV起搏（在+80毫秒至 -80毫秒之间采用个体化优化的室间间期值）实现的室内再同步程度。左心室内延迟定义为左心室六个基底节段最长激活时间与最短激活时间之差。异常左心室内延迟定义为值>41毫秒。左心室内延迟基线时为63±28毫秒，BIV 0时降至44±26毫秒，优化BIV时降至26±15毫秒（P = 0.001）。BIV 0使28例（41%）患者的延迟最短（23±12毫秒）。在41例（59%）患者中，采用优化的室间间期（32例左心室先起搏，5例右心室先起搏）或单腔起搏（3例左心室起搏，1例右心室起搏）可实现更好的再同步。采用BIV 0时，41%的患者左心室内延迟仍异常，30%的患者左心室内延迟长于基线，相比之下，优化BIV时分别为9%和12%（P = 0.001）。
大多数患者采用同步BIV起搏实现的再同步效果欠佳。对右心室和左心室起搏的相对贡献进行个性化程控是改善CRT效果的前提条件。
