Abstract：
BACKGROUND: The accuracy of surface ECG algorithms for predicting the origin of outflow tract ventricular arrhythmias (OT-VAs) might be questioned. Intracardiac electrograms recorded at anatomic landmarks could provide new predictive insights. We aim to evaluate the efficacy of a novel criterion utilizing the activation pattern of the coronary sinus (CS) in localizing OT-VAs, including VAs originating from the right ventricular outflow tract (RVOT), endocardial left ventricular outflow tract (Endo-LVOT), and epicardial left ventricular outflow tract (Epi-LVOT).
METHODS: We measured the ventricular activation time of the mitral annulus (MA) from the onset of the earliest QRS complex of VAs to the initial deflection over the isoelectric line at local signals, namely the QRS-MA interval. The activation at 3 and 12 o\'clock of the MA was recorded as the QRS-MA3 and QRS-MA12 intervals, respectively. Their predictive values were compared to previous ECG algorithms.
RESULTS: A total of 68 patients with OT-VAs were enrolled (51 for development and 17 for validation). From early to late, the ventricular activation sequences at MA12 were as follows: Epi-LVOT, Endo-LVOT, and RVOT. In LBBB morphology OT-VAs, the QRS-MA12 interval was significantly earlier for LVOT origins than RVOT origins. In the combined cohort of development and validation cohort, a cut-off value of ≤10 ms predicted the LVOT origin with a sensitivity of 100% and specificity of 78%. The QRS-MA12 interval ≤ -24 ms additionally predicted epicardial LVOT sites of origin.
CONCLUSIONS: The QRS-MA interval could accurately differentiate the OT-VAs localization.
METHODS: We measured the ventricular activation time of the mitral annulus (MA) from the onset of the earliest QRS complex of VAs to the initial deflection over the isoelectric line at local signals, namely the QRS-MA interval. The activation at 3 and 12 o\'clock of the MA was recorded as the QRS-MA3 and QRS-MA12 intervals, respectively. Their predictive values were compared to previous ECG algorithms.
RESULTS: A total of 68 patients with OT-VAs were enrolled (51 for development and 17 for validation). From early to late, the ventricular activation sequences at MA12 were as follows: Epi-LVOT, Endo-LVOT, and RVOT. In LBBB morphology OT-VAs, the QRS-MA12 interval was significantly earlier for LVOT origins than RVOT origins. In the combined cohort of development and validation cohort, a cut-off value of ≤10 ms predicted the LVOT origin with a sensitivity of 100% and specificity of 78%. The QRS-MA12 interval ≤ -24 ms additionally predicted epicardial LVOT sites of origin.
CONCLUSIONS: The QRS-MA interval could accurately differentiate the OT-VAs localization.
摘要：
背景：表面ECG算法预测流出道室性心律失常（OT-VA）起源的准确性可能受到质疑。在解剖标志处记录的心内电描记图可以提供新的预测性见解。我们的目标是评估一种新的标准的有效性，利用冠状窦（CS）的激活模式定位OT-VA，包括源自右心室流出道（RVOT）的VA，心内膜左心室流出道(Endo-LVOT),和心外膜左心室流出道（Epi-LVOT）。
方法：我们测量了从VAs的最早QRS波群开始到局部信号的等电线上的初始偏转的二尖瓣环（MA）的心室激活时间，即QRS-MA间隔。将MA在3和12点的激活记录为QRS-MA3和QRS-MA12间隔，分别。将其预测值与先前的ECG算法进行比较。
结果：共纳入68例OT-VAs患者（51例用于开发，17例用于验证）。从早到晚,MA12时的心室激动序列如下：Epi-LVOT，Endo-LVOT,和RVOT。在LBBB形态OT-VAs中，LVOT起源的QRS-MA12间隔明显早于RVOT起源。在开发和验证队列的合并队列中，≤10ms的截断值预测LVOT起源的敏感性为100%,特异性为78%.QRS-MA12间期≤-24ms额外预测了心外膜LVOT的起源部位。
结论：QRS-MA间期能准确区分OT-VAs定位。
方法：我们测量了从VAs的最早QRS波群开始到局部信号的等电线上的初始偏转的二尖瓣环（MA）的心室激活时间，即QRS-MA间隔。将MA在3和12点的激活记录为QRS-MA3和QRS-MA12间隔，分别。将其预测值与先前的ECG算法进行比较。
结果：共纳入68例OT-VAs患者（51例用于开发，17例用于验证）。从早到晚,MA12时的心室激动序列如下：Epi-LVOT，Endo-LVOT,和RVOT。在LBBB形态OT-VAs中，LVOT起源的QRS-MA12间隔明显早于RVOT起源。在开发和验证队列的合并队列中，≤10ms的截断值预测LVOT起源的敏感性为100%,特异性为78%.QRS-MA12间期≤-24ms额外预测了心外膜LVOT的起源部位。
结论：QRS-MA间期能准确区分OT-VAs定位。
