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Updated: Jun 10, 2026

Dual-Dye Optical Mapping of Hearts from RyR2R2474S Knock-In Mice of Catecholaminergic Polymorphic Ventricular Tachycardia
Published on: December 22, 2023
In vivo studies of Scn5a+/- mice modeling Brugada syndrome demonstrate both conduction and repolarization
Claire A Martin1, Yanmin Zhang, Andrew A Grace
1Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom. clairemartin@gmail.com
Objectives:
We investigate the extent to which the electrocardiographic (ECG) properties of intact Scn5a+/- mice reproduce the corresponding clinical Brugada syndrome phenotype and use this model to investigate the role of conduction and repolarization abnormalities in the arrhythmogenic mechanism.
Methods And Results:
The ECGs were obtained from anesthetized wild-type and Scn5a+/- mice, before and after administration of the known pro- and antiarrhythmic agents flecainide and quinidine. The ECG intervals were measured and their dispersions calculated. Scn5a+/- hearts showed ventricular arrhythmias, ST elevation, and conduction disorders including increased QT dispersion, accentuated by flecainide. Quinidine did not cause ventricular arrhythmias but exerted variable effects on ST segments and worsened conduction abnormalities.
Conclusions:
The ECG features in an Scn5a+/- mouse establish it as a suitable model for Brugada syndrome and demonstrate abnormal conduction and repolarization phenomena. Altered QT dispersion, taken to indicate increased transmural repolarization gradients, may be useful in clinical risk stratification.

