Alternans of the T wave in ECG (TWA) has high negative but poor positive predictive value in the prediction of ventricular arrhythmia. Alternans of repolarization duration, i.e. of action potential duration (APD), causes TWA. Prior studies from our group showed that alternans of the maximum rate of depolarization also occurs when APD alternans occurs and the relationship between these two has the potential to affect formation of spatial discord, which may be more arrhythmogenic. Therefore, exploration of the co-occurrence of the alternans of depolarization and repolarization has the potential to improve the prediction. In the present study, we used a mathematical model to show that depolarization alternans appears as alternating amplitude of the R wave in the ECG. We also investigated the link between changes in R wave amplitude and TWA. Results from clinical grade ECGs available in the PhysioNet database show that amplitude of the R wave can change as predicted by our experimental results and the mathematical model. Using TWA as the marker of repolarization alternans and R wave amplitude alternans (RWAA) as the marker of depolarization alternans, we investigated the phase relation between them and observed that, similar to previous results from animals, the phase relation between the two can spontaneously change. That is, alternans of depolarization does co-occur with TWA and the phase relationship between the two is not invariant. These results support further investigation of the use of RWAA as a complementary method to TWA to improve positive predictive value for prediction of ventricular arrhythmia.

心电图（TWA）中的T波交替蛋白在预测室性心律失常中具有较高的阴性预测值，但阳性预测值较差。复极持续时间（即动作电位持续时间（APD））的交替时间导致TWA。我们小组的先前研究表明，当APD交替发生时，最大去极化率的交替发生也发生，这两者之间的关系可能会影响空间不和谐的形成，这可能会导致更多的心律失常。因此，探索去极化和复极化交替出现的同时存在可能改善预测。在本研究中，我们使用数学模型来显示去极化交联蛋白在ECG中以R波的交替振幅出现。我们还研究了R波振幅变化与TWA之间的联系。PhysioNet数据库中提供的临床级ECG的结果表明，R波的幅度可以根据我们的实验结果和数学模型进行预测。使用TWA作为复极化奥特那的标记，并用R波振幅交联剂（RWAA）作为去极化的交替子的标记，我们研究了它们之间的相位关系，并观察到，类似于先前的动物实验结果，两者之间的相位关系可以自发改变。即，去极化的交替性确实与TWA同时发生，并且两者之间的相位关系不是不变的。这些结果支持进一步研究使用RWAA作为TWA的补充方法，以提高预测室性心律失常的阳性预测值。