University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
JACC Cardiovasc Imaging. 2010 Feb;3(2):132-40. doi: 10.1016/j.jcmg.2009.09.020.
To test the hypothesis that echocardiographic dyssynchrony may assist in the selection of patients with borderline QRS duration for cardiac resynchronization therapy (CRT).
Although echocardiographic dyssynchrony is currently not recommended to select patients with QRS duration widening for CRT, its utility in patients with borderline QRS widening is unclear.
Of 221 consecutive heart failure patients with an ejection fraction (EF) < or =35% referred for CRT, 86 had a borderline QRS duration of 100 to 130 ms (115 +/- 8 ms) and 135 patients had wide QRS >130 ms (168 +/- 26 ms). Dyssynchrony was assessed using interventricular mechanical delay, tissue Doppler imaging longitudinal velocity opposing wall delay, and speckle tracking radial strain for septal to posterior wall delay. Response to CRT was defined as > or =15% increase in EF, and reverse remodeling as > or =10% decrease in end-systolic volume.
There were 201 patients with baseline quantitative echocardiographic data available, and 187 with follow-up data available 8 +/- 5 months after CRT. A smaller proportion of borderline QRS duration patients (53%) were EF responders compared with 75% with widened QRS (p < 0.05). Interventricular mechanical delay > or =40 ms and opposing wall delay > or =65 ms were predictive of EF response in the wide QRS duration group, but not the borderline QRS duration group. Speckle tracking radial dyssynchrony > or =130 ms, however, was predictive of EF response in both wide QRS interval patients (88% sensitivity, 74% specificity) and borderline QRS interval patients (79% sensitivity, 82% specificity) and associated reverse remodeling with reduction in end-systolic volume (p < 0.0005).
Radial dyssynchrony by speckle tracking strain was associated with EF and reverse remodeling response to CRT in patients with borderline QRS duration and has the potential to assist with patient selection.
验证超声心动图不同步可帮助选择 QRS 时限处于临界值的患者行心脏再同步治疗（CRT）的假设。
目前，尽管超声心动图不同步不推荐用于选择 QRS 时限增宽的 CRT 患者，但在 QRS 时限处于临界值的患者中其作用尚不明确。
221 例连续心力衰竭患者射血分数（EF）＜或＝35%，推荐行 CRT，其中 86 例 QRS 时限为 100～130ms（115±8ms），135 例 QRS 时限＞130ms（168±26ms）。采用室间机械延迟、组织多普勒成像纵向速度反向壁延迟和斑点追踪径向应变评估间隔至后壁延迟的不同步性。CRT 反应定义为 EF 增加＞或＝15%，逆重构定义为左室收缩末期容积减少＞或＝10%。
201 例患者有基线定量超声心动图数据，187 例有 CRT 后 8±5 个月的随访数据。与 QRS 时限增宽的患者（75%）相比，QRS 时限处于临界值的患者（53%）EF 反应比例更小（p＜0.05）。QRS 时限增宽组中，室间机械延迟＞或＝40ms 和反向壁延迟＞或＝65ms 预测 EF 反应，而 QRS 时限处于临界值组中则不然。然而，斑点追踪径向不同步＞或＝130ms 预测 QRS 时限增宽患者（88%的敏感性，74%的特异性）和 QRS 时限处于临界值患者（79%的敏感性，82%的特异性）EF 反应及左室收缩末期容积减少的逆重构（p＜0.0005）。
斑点追踪应变的径向不同步与 EF 和 CRT 逆重构反应相关，可用于选择 QRS 时限处于临界值的患者。
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