Measurement and interpretation of electrocardiographic QT intervals in murine hearts

Murine hearts (Langendorff-perfused mouse hearts and whole anesthetized mice), including Scn5a+/ΔKPQ hearts used to model human long QT syndrome

QT1 measurement method (measured to the recovery of the ECG trace to the isoelectric baseline for entirely positive T-waves or to the trough of any negative T-wave undershoot)

QT2 measurement method (measured to the return of any ECG trough to the isoelectric baseline)

Correlation with changes in the duration of ventricular myocyte action potentials (Q-APR90)surrogate