1. Cardiac-specific overexpression of SCN5A gene leads to shorter P wave duration and PR interval in transgenic mice.
- Author
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Zhang T, Yong SL, Tian XL, and Wang QK
- Subjects
- Action Potentials, Animals, Arrhythmias, Cardiac genetics, Electrocardiography, Heart physiology, Heart physiopathology, Heart Rate, Humans, Mice, Mice, Transgenic, NAV1.5 Voltage-Gated Sodium Channel, Phenotype, Gene Expression, Sodium Channels genetics
- Abstract
The Cardiac sodium channel gene SCN5A plays a critical role in cardiac electrophysiology and its mutations, either gain- or loss-of-functions, are associated with lethal arrhythmias. In this study, we investigated the effect of overexpression of SCN5A on the cardiac phenotype in a transgenic mouse model (TG-WT L10). Compared to NTG mice, heart rate, QRS duration, and QT intervals remained unchanged in TG-WT mice. Moreover, no spontaneous ventricular arrhythmias were detected in TG-WT hearts. Despite these results, a mild, irregular cardiac phenotype was observed in TG-WT mice. The P wave and PR interval were significantly shorter in TG-WT compared with NTG mice (P, 8.8+/-0.8 ms vs. 12.6+/-0.9 ms; PR, 12.5+/-2 ms vs. 33.5+/-0.7 ms). Furthermore, spontaneous premature atrial contractions were often detected in TG-WT mice. These results suggest that the expression level of the SCN5A gene is a determinant for the length of the P wave duration and PR interval on electrocardiograms (ECG).
- Published
- 2007
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