Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Eur Heart J Cardiovasc Imaging. 2012 Jan;13(1):86-94. doi: 10.1093/ejechocard/jer167. Epub 2011 Sep 15.
Current imaging techniques attempt to identify responders to cardiac resynchronization therapy (CRT). However, because CRT response may depend upon several factors, it may be clinically more useful to identify patients for whom CRT would not be beneficial even under optimal conditions. We aimed to determine the negative predictive value of a composite echocardiographic index evaluating atrial-ventricular dyssynchrony (AV-DYS) and intraventricular dyssynchrony.
Subjects with standard indications for CRT underwent echo before and during the month following device implantation. AV-DYS was defined as a percentage of left ventricular (LV) filling time over the cardiac cycle. AV-DYS, which produces a characteristic rocking of the LV apex, was quantified as the percentage of the cardiac cycle over which tissue Doppler-derived displacement curves of the septal and lateral walls showed discordance. CRT responder status was determined based on the early haemodynamic response to CRT (intra-individual improvement >25% in the Doppler-derived LV dP/dt). Among 40 patients, optimal cut-points predicting CRT response were 31% for LV apical rocking and 39% for AV-DYS. The presence of either apical rocking >31% or AV-DYS ≤ 39% had a sensitivity of 95%, specificity of 80%, positive predictive value of 83%, and a negative predictive value of 94% for CRT response.
After pre-selection of candidates for CRT by QRS duration, application of a simple composite echocardiographic index may exclude patients who would be non-responders to CRT and thus improve the global rate of therapy success.
目前的影像学技术试图识别心脏再同步治疗（CRT）的应答者。然而，由于 CRT 应答可能取决于几个因素，因此在最佳条件下，识别 CRT 无益的患者可能在临床上更有用。我们旨在确定评估房室（AV）不同步和室内不同步的综合超声心动图指数的阴性预测值。
具有 CRT 标准适应证的受试者在植入设备前和植入后一个月内进行了超声心动图检查。AV-DYS 定义为左心室（LV）充盈时间占心动周期的百分比。AV-DYS 产生 LV 心尖的特征性摇摆，通过组织多普勒衍生的间隔和侧壁位移曲线显示的不和谐来量化，其占心动周期的百分比。CRT 应答状态基于 CRT 的早期血液动力学反应来确定（多普勒衍生的 LV dP/dt 个体内改善>25%）。在 40 例患者中，预测 CRT 反应的最佳截断点为 LV 心尖摇摆>31%和 AV-DYS≤39%。存在心尖摇摆>31%或 AV-DYS≤39%的患者，CRT 反应的敏感性为 95%，特异性为 80%，阳性预测值为 83%，阴性预测值为 94%。
在通过 QRS 持续时间预选 CRT 候选者后，应用简单的综合超声心动图指数可以排除对 CRT 无应答的患者，从而提高整体治疗成功率。
