Background

Right bundle branch block (RBBB) can be benign or associated with right ventricular (RV) functional and structural abnormalities. Our aim was to evaluate QRS-T voltage-time-integral (VTI) compared to QRS duration and lead V1 R' as markers for RV abnormalities.

Methods

We included adults with an ECG demonstrating RBBB and echocardiogram obtained within 3 months of each other, between 2010 and 2020. VTI_QRS and VTI_QRST were obtained for 12 standard ECG leads, reconstructed vectorcardiographic X, Y, Z leads and root-mean-squared (3D) ECG. Age, sex and BSA-adjusted linear regressions were used to assess associations of QRS duration, amplitudes, VTIs and lead V1 R' duration/VTI with echocardiographic tricuspid annular plane systolic excursion (TAPSE), RV tissue Doppler imaging S′, basal and mid diameter, and systolic pressure (RVSP).

Results

Among 782 patients (33% women, age 71 ± 14 years) with RBBB, R' duration in lead V1 was modestly associated with RV S′, RV diameters and RVSP (all p ≤ 0.03). QRS duration was more strongly associated with RV diameters (both p < 0.0001). Amplitude_QRS-Z was modestly correlated with all 5 RV echocardiographic variables (all p ≤ 0.02). VTI_R’-V1 was more strongly associated with TAPSE, RV S′ and RVSP (all p ≤ 0.0003). VTI_QRS-Z and VTI_QRST-Z were among the strongest correlates of the 5 RV variables (all p < 0.0001). VTI_QRST-Z.√BSA cutoff of ≥62 μVsm had sensitivity 62.7% and specificity 65.7% for predicting ≥3 of 5 abnormal RV variables (AUC 0.66; men 0.71, women 0.60).

Conclusion

In patients with RBBB, VTI_QRST-Z is a stronger predictor of RV dysfunction and adverse remodeling than QRS duration and lead V1 R'.

中文翻译：

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典型右束支传导阻滞患者的心电图 Z 轴 QRS-T 电压-时间积分 – 与超声心动图右心室大小和功能的相关性

背景

右束支传导阻滞 (RBBB) 可以是良性的，也可以与右心室 (RV) 功能和结构异常相关。我们的目的是评估 QRS-T 电压时间积分 (VTI) 与 QRS 持续时间和导联 V1 R' 相比作为 RV 异常的标志。

方法

我们纳入了心电图显示 RBBB 的成年人，并在 2010 年至 2020 年之间的 3 个月内获得了超声心动图。VTI _QRS和 VTI _QRST是通过 12 个标准心电图导联、重建心向量图 X、Y、Z 导联和均方根获得的(3D) 心电图。使用年龄、性别和 BSA 调整的线性回归来评估 QRS 持续时间、幅度、VTI 和导联 V1 R' 持续时间/VTI 与超声心动图三尖瓣环平面收缩期偏移 (TAPSE)、RV 组织多普勒成像 S'、基础和中期的关联直径和收缩压 (RVSP)。

结果

在 782 名 RBBB 患者（33% 女性，年龄 71 ± 14 岁）中，V1 导联 R' 持续时间与 RV S'、RV 直径和 RVSP 适度相关（所有p  ≤ 0.03）。QRS 时限与 RV 直径的相关性更强（均p  < 0.0001）。_QRS-Z幅度与所有 5 个 RV 超声心动图变量适度相关（所有p  ≤ 0.02）。VTI _R'-V1与 TAPSE、RV S' 和 RVSP 的相关性更强（所有p  ≤ 0.0003）。VTI _QRS-Z和 VTI _QRST-Z是 5 个 RV 变量的最强相关性之一（所有p  < 0.0001）。VTI _QRST-Z .√BSA 截止值≥62 μVsm 对于预测 5 个异常 RV 变量中的≥3 个变量的敏感性为 62.7%，特异性为 65.7%（AUC 0.66；男性 0.71，女性 0.60）。

结论

在 RBBB 患者中，VTI _QRST-Z比 QRS 时限和导联 V1 R' 更能预测 RV 功能障碍和不良重构。