Yusuf Jamal, Agrawal Devendra Kumar, Mukhopadhyay Saibal, Mehta Vimal, Trehan Vijay, Tyagi Sanjay
Department of Cardiology, G.B. Pant Hospital, New Delhi, India.
Indian Heart J. 2013 Mar-Apr;65(2):172-9. doi: 10.1016/j.ihj.2013.02.007. Epub 2013 Mar 4.
Cardiac resynchronization therapy is an important therapeutic modality in drug refractory symptomatic patients of heart failure with wide QRS (≥120 ms) on electrocardiogram. However, wide QRS (considered as a marker of electrical dyssynchrony) occurs in only 30% of heart failure patients, making majority of drug refractory heart failure patients ineligible for resynchronization therapy. Significant numbers of patients with narrow QRS have echocardiographic evidence of left ventricular dyssynchrony. However, there is sparse data about additional features on the surface ECG which can predict intraventricular dyssynchrony. This study was undertaken to assess the utility of fragmented narrow QRS complex to predict significant intraventricular dyssynchrony in symptomatic patients of non-ischemic dilated cardiomyopathy.
100 symptomatic patients of non-ischemic dilated cardiomyopathy with narrow QRS complexes (50 each with fragmented and normal QRS) were recruited. Tissue Doppler imaging was used to assess intraventricular dyssynchrony as per 'Yu index'.
78% patients (n = 39) in fQRS complex group and 14% (n = 7) in normal QRS complex group had significant intraventricular dyssynchrony (χ(2) = 20.61; p < 0.000005). fQRS complexes had 84.78% sensitivity, 79.62% specificity, a positive predictive value of 78% and negative predictive value of 86% to detect intraventricular dyssynchrony. fQRS also had sensitivity and specificity of 93% and 90% respectively to localize the dyssynchronous segment.
fQRS is a marker of electrical dyssynchrony, which results in significant intraventricular dyssynchrony in patients of non-ischemic dilated cardiomyopathy and a narrow QRS interval. fQRS localizes the dyssynchronous segment and might be useful in identifying patients who can benefit from cardiac resynchronization therapy.
心脏再同步治疗是心电图显示QRS波增宽（≥120毫秒）的药物难治性有症状心力衰竭患者的一种重要治疗方式。然而，QRS波增宽（被视为电不同步的一个标志）仅出现在30%的心力衰竭患者中，这使得大多数药物难治性心力衰竭患者不符合再同步治疗的条件。大量QRS波狭窄的患者有左心室不同步的超声心动图证据。然而，关于体表心电图上能够预测心室内不同步的其他特征的数据却很少。本研究旨在评估碎裂窄QRS波群对预测非缺血性扩张型心肌病有症状患者显著心室内不同步的效用。
招募了100名有症状的非缺血性扩张型心肌病且QRS波狭窄的患者（各50名分别有碎裂和正常QRS波）。根据“Yu指数”，采用组织多普勒成像评估心室内不同步情况。
碎裂QRS波群组78%的患者（n = 39）和正常QRS波群组14%的患者（n = 7）有显著的心室内不同步（χ(2)=20.61；p < 0.000005）。碎裂QRS波群检测心室内不同步的敏感性为84.78%，特异性为79.62%，阳性预测值为78%，阴性预测值为86%。碎裂QRS波群定位不同步节段的敏感性和特异性分别为93%和90%。
碎裂QRS波群是电不同步的一个标志，其导致非缺血性扩张型心肌病且QRS间期狭窄的患者出现显著的心室内不同步。碎裂QRS波群可定位不同步节段，可能有助于识别能从心脏再同步治疗中获益的患者。
