Aims

Electrocardiographic imaging (ECGi) and the ECG belt are body surface potential mapping systems which can assess electrical dyssynchrony in patients undergoing cardiac resynchronization therapy (CRT). ECGi-derived dyssynchrony metrics are calculated from reconstructed epicardial potentials based on body surface potentials combined with a thoracic CT scan, while the ECG belt relies on body surface potentials alone. The relationship between dyssynchrony metrics from these two systems is unknown. In this study we aim to compare intra-ventricular and inter-ventricular dyssynchrony metrics between ECGi and the ECG belt.

Methods

Seventeen patients underwent ECGi after CRT. A subsample of 40 body surface potentials was used to simulate the ECG belt. ECGi dyssynchrony metrics, calculated from reconstructed epicardial potentials, and ECG belt dyssynchrony metrics, calculated from the sampled body surface potentials were compared.

Results

There was a strong positive correlation between ECGi left ventricular activation time (LVAT) and ECG belt left thorax activation time (LTAT) (R = 0.88 ; P < 0.001) and between ECGi standard deviation of activation times (SDAT) and ECG belt-SDAT (R = 0.76; P < 0.001) during intrinsic rhythm. The correlation for both pairs was also strong during biventricular pacing. Ventricular electrical uncoupling, a well validated ECGi inter-ventricular dyssynchrony metric, correlated strongly with ECG belt-SDAT during intrinsic rhythm (R = 0.76; P < 0.001) but not biventricular pacing (R = 0.29; P = 0.26). Cranial or caudal displacement of the simulated ECG belt did not affect LTAT or SDAT.

Conclusion

ECGi- and ECG belt-derived intra-ventricular and inter-ventricular dyssynchrony metrics were strongly correlated. The ECG belt may offer comparable dyssynchrony assessment to ECGi, with associated practical and cost advantages.

中文翻译：

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心电图成像与模拟心电图带电不同步参数的比较

宗旨

心电图成像 (ECGi) 和 ECG 带是体表电位测绘系统，可以评估接受心脏再同步治疗 (CRT) 的患者的电不同步。ECGi 衍生的不同步指标是根据基于体表电位结合胸部 CT 扫描的重建心外膜电位计算得出的，而 ECG 带仅依赖于体表电位。这两个系统的不同步指标之间的关系是未知的。在这项研究中，我们旨在比较 ECGi 和 ECG 带之间的心室内和心室间不同步指标。

方法

17 名患者在 CRT 后接受了 ECGi。使用 40 个体表电位的子样本来模拟 ECG 带。比较了根据重建的心外膜电位计算的 ECGi 不同步指标和根据采样的体表电位计算的 ECG 带不同步指标。

结果

ECGi 左心室激动时间 (LVAT) 与 ECG 带左胸激动时间 (LTAT) ( R = 0.88 ; P < 0.001) 以及 ECGi 激动时间标准差 (SDAT) 与 ECG 带-SDAT 之间存在强正相关( R = 0.76; P < 0.001) 在固有节律期间。在双心室起搏期间，两对的相关性也很强。心室电解偶联是一种经过充分验证的 ECGi 心室间不同步度量，与固有节律期间的 ECG 带-SDAT 密切相关（R = 0.76；P < 0.001），但与双心室起搏无关（R = 0.29；P= 0.26）。模拟 ECG 带的头颅或尾椎位移不影响 LTAT 或 SDAT。

结论

心电图和心电图带衍生的心室内和心室间不同步指标有很强的相关性。ECG 带可以提供与 ECGi 相当的不同步评估，并具有相关的实用和成本优势。