Electrocardiogram (ECG) Rhythm App: Corrected QT is designed to help health professional to assess the QT interval from an electrocardiogram (ECG) result. The QT interval in electrocardiogram (ECG) is representing ventricles depolarization and repolarization. Why should you choose "Electrocardiogram (ECG) Rhythm App: Corrected QT"? Simple and very easy to use.