Objective

It is practical and useful to detect patients who benefit from cardiac resynchronization therapy (CRT) by electrocardiographic (ECG) methods. In this study, the predictive role of the frontal QRS-T angle and other ECG parameters was evaluated in CRT responder patients.

Method

Seventy-seven consecutive patients with left ventricular ejection fraction (LVEF) ≤ 35%, New York Heart Association (NYHA) classes II-III, ambulatory class IV and normal sinus rhythm, who had complete left bundle branch block and were treated with CRT were included in this study. Patients were classified as “CRT responders” and “CRT non responders” according to their LVEF improvement. The frontal QRS-T angle was calculated as the absolute value of the difference between the QRS and T wave axes [frontal QRS-T angle = (QRS axis-T axis)].

Results

The mean age of the patients was 64.5 ± 9.1 years, and the average follow-up was 28 (12–47) months. The post-implantation LVEF was higher in the patients CRT responders group (p < 0.001). Post–implantation frontal QRS-T angle (p = 0.003), QRS duration (p = 0.008) and cQT interval (p = 0.012) values were much shorter in the CRT responder group. Multivariable regression analyses showed that the frontal QRS-T angle and age were independent risk factors for CRT response (p = 0.009). The results of the receiver operating characteristic curve analyses (ROC) showed that the predictive optimal cut-off value of CRT response for the frontal QRS-T angle was <135 degrees (AUC: 0.69, 95% CI 0.575–0.814, p = 0.004).

Conclusion

The narrowed frontal QRS-T angle (<135 degrees), QRS duration and cQT interval were associated with CRT response in heart failure patients. The frontal QRS-T angle can be an independent predictor of CRT response.

中文翻译：

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心脏再同步化治疗后额波QRS-T角的预测价值

客观的

通过心电图 (ECG) 方法检测受益于心脏再同步治疗 (CRT) 的患者是实用且有用的。在这项研究中，评估了 CRT 反应者患者的额叶 QRS-T 角和其他心电图参数的预测作用。

方法

连续 77 名左心室射血分数 (LVEF) ≤ 35%、纽约心脏协会 (NYHA) 分级 II-III、非卧床分级 IV 级、窦性心律正常、完全左束支传导阻滞并接受 CRT 治疗的连续患者纳入本研究。根据患者的 LVEF 改善情况，将患者分为“CRT 反应者”和“CRT 无反应者”。额QRS-T角计算为QRS和T波轴差值的绝对值[额QRS-T角=（QRS轴-T轴）]。

结果

患者的平均年龄为 64.5 ± 9.1 岁，平均随访时间为 28 (12-47) 个月。患者 CRT 反应组的植入后 LVEF 较高 ( p < 0.001)。CRT 反应组的植入后额叶 QRS-T 角 ( p = 0.003)、QRS 持续时间 ( p = 0.008) 和 cQT 间期 ( p = 0.012) 值要短得多。多变量回归分析表明，额叶 QRS-T 角和年龄是 CRT 反应的独立危险因素（p = 0.009）。接受者操作特征曲线分析 (ROC) 的结果表明，CRT 响应对正面 QRS-T 角的预测最佳截止值 <135 度（AUC：0.69，95% CI 0.575–0.814，p = 0.004）。

结论

狭窄的额叶 QRS-T 角（<135 度）、QRS 持续时间和 cQT 间期与心力衰竭患者的 CRT 反应相关。正面 QRS-T 角可以是 CRT 反应的独立预测因子。