Division of Cardiology, Seoul National University Bundang Hospital, Seoul National University, Seoul, South Korea.
Heart. 2010 Jul;96(13):1029-32. doi: 10.1136/hrt.2009.167585. Epub 2009 Nov 11.
Recent clinical trials have challenged the clinical applicability of mechanical dyssynchrony in predicting cardiac resynchronisation therapy response.
To evaluate whether mechanical dyssynchrony has an additional benefit over QRS duration in predicting cardiac events in patients with systolic heart failure.
A total 167 patients admitted to hospital with heart failure (age 65+/-12, ejection fraction <35%) were followed up prospectively. Using tissue Doppler imaging (TDI), the time to peak systolic velocity during the ejection phase was measured in the basal septal and lateral segments. A temporal difference between the septal to lateral wall (Ts-l) of > or =65 ms was defined as a mechanical dyssynchrony.
After 33 months of follow-up, 70 patients (41.9%) had cardiac events, including 42 (25.1%) with cardiac death. The event-free survival time decreased as Ts-l or QRS duration increased. Patients with QRS > or =120 ms had increased risks of cardiac events by multivariate Cox proportional hazard analysis (HR=1.88, 95% CI 1.07 to 3.29, p = 0.028). The presence of mechanical dyssynchrony also predicted an increased risk of cardiac events (HR=2.37, 95% CI 1.39 to 4.04, p = 0.002). Those with both electrical and mechanical dyssynchrony had a HR of 3.98 (95% CI 2.02 to 7.86, p <0.001) when compared with those with normal QRS duration and absence of mechanical dyssynchrony. The addition of mechanical dyssynchrony significantly improved the prognostic power of a model containing echocardiographic parameters and QRS duration.
TDI-derived mechanical dyssynchrony is an important prognosticator and independently associated with QRS duration in predicting adverse events in patients with systolic heart failure.
最近的临床试验对机械不同步在预测心脏再同步治疗反应中的临床适用性提出了挑战。
评估机械不同步在预测收缩性心力衰竭患者心脏事件方面是否优于 QRS 持续时间。
前瞻性纳入 167 例因心力衰竭住院的患者（年龄 65+/-12 岁，射血分数 <35%）。使用组织多普勒成像（TDI）测量射血期时基底室间隔和侧壁的收缩期峰值速度到达时间。室间隔到侧壁的时间差（Ts-l）>或=65ms 定义为机械不同步。
随访 33 个月后，70 例（41.9%）患者发生心脏事件，其中 42 例（25.1%）死于心脏原因。Ts-l 或 QRS 持续时间增加时，无事件生存时间减少。多变量 Cox 比例风险分析显示 QRS >或=120ms 的患者发生心脏事件的风险增加（HR=1.88，95%CI 1.07 至 3.29，p=0.028）。存在机械不同步也预示着发生心脏事件的风险增加（HR=2.37，95%CI 1.39 至 4.04，p=0.002）。与 QRS 正常且不存在机械不同步的患者相比，同时存在电和机械不同步的患者 HR 为 3.98（95%CI 2.02 至 7.86，p<0.001）。在包含超声心动图参数和 QRS 持续时间的模型中加入机械不同步，可显著提高预后预测能力。
TDI 衍生的机械不同步是一个重要的预测因子，与 QRS 持续时间一样，可独立预测收缩性心力衰竭患者的不良事件。
