Instituto Argentino de Matemática (IAM), CONICET, Instituto de Investigaciones Biomédicas (IIBM), University of Buenos Aires (UBA), Buenos Aires, Argentina.
Hospital de Diagnóstico Escalón, Facultad de Medicina, Universidad Salvadoreña Alberto Masferrer, San Salvador, El Salvador.
J Interv Card Electrophysiol. 2021 Dec;62(3):479-485. doi: 10.1007/s10840-021-00999-9. Epub 2021 May 20.
Electrical transmission disorders have a deleterious effect on cardiac depolarization, resulting in a disorganized ventricular contraction that reduces global mechanical efficiency; this mechanical dyssynchrony can be corrected by cardiac resynchronization therapy. However, despite adjustments in the electrical criteria selection of QRS for the recognition of mechanical dyssynchrony, a significant proportion of patients do not currently respond to this therapy.
To find if a new predictor of dyssynchrony, the electrocardiogram spatial variance, is a better marker of mechanical dyssynchrony than QRS duration.
Forty-seven electrocardiograms and 47 strain (2D speckle tracking) echocardiograms were prospectively collected simultaneously in consecutive, non-selected patients; the left ventricular mechanical dispersion was measured in all the cases. The electrocardiographic analysis of variance was made with a digital superposition of the electrocardiographic leads and generates different indexes of variance of both QRS complex and repolarization phase.
ROC analysis probed that the best area under the curve (AUC) value correlated with left ventricular mechanical dispersion and was obtained combining several spatial variance markers (considering depolarization and repolarization spatial variance together; AUC = 0.97); the same analysis using the QRS duration versus mechanical dispersion showed a significantly lower AUC value (AUC = 0.64).
Spatial variance combining depolarization and repolarization markers is a superior predictor of left ventricular mechanical dispersion than QRS duration.
电传输障碍对心脏去极化有有害影响，导致心室收缩无序，降低整体机械效率；这种机械不同步可以通过心脏再同步治疗来纠正。然而，尽管对 QRS 进行了电标准调整以识别机械不同步，但仍有相当一部分患者目前对此治疗没有反应。
寻找一种新的电不同步预测指标——心电图空间方差，是否比 QRS 持续时间更能预测机械不同步。
前瞻性地连续收集 47 例非选择性患者的 47 次心电图和 47 次应变（二维斑点追踪）超声心动图；所有病例均测量左心室机械弥散度。心电图方差分析采用数字叠加心电图导联，生成 QRS 复合波和复极相位的不同方差指标。
ROC 分析显示，与左心室机械弥散度相关性最佳的曲线下面积（AUC）值是通过组合几个空间方差指标获得的（同时考虑去极化和复极空间方差；AUC=0.97）；而使用 QRS 持续时间与机械弥散度进行的相同分析显示 AUC 值显著降低（AUC=0.64）。
综合考虑去极化和复极标志的空间方差是预测左心室机械弥散度的更好指标，优于 QRS 持续时间。
