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Updated: May 22, 2026
08:34
Isolation of Atrial Myocytes from Adult Mice
Published on: July 25, 2019
Conduction and refractory disorders in the diabetic atrium
Masaya Watanabe1, Hisashi Yokoshiki, Hirofumi Mitsuyama
1Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Summary
Diabetes mellitus (DM) increases atrial fibrillation risk by altering heart electrical activity. Diabetic rat atria showed slower, more varied electrical conduction and prolonged action potential duration, increasing arrhythmia susceptibility.
Area of Science:
- Cardiovascular Physiology
- Electrophysiology
- Diabetology
Background:
- Diabetes mellitus (DM) is a known risk factor for atrial fibrillation (AF).
- The specific electrophysiological mechanisms underlying AF in diabetic patients remain incompletely understood.
Purpose of the Study:
- To investigate the impact of diabetes on atrial electrophysiology, focusing on action potential propagation and spatiotemporal dispersion.
- To elucidate the arrhythmogenic substrates in the diabetic atrium.
Main Methods:
- Diabetes was induced in Wistar rats using streptozotocin.
- Optical mapping and histological analysis were performed on right atria from control and diabetic rats.
- Conduction velocity, action potential duration, and alternans were measured under various pacing conditions.
Main Results:
- Diabetic rats exhibited prolonged atrial tachyarrhythmia duration, decreased conduction velocity, and increased conduction heterogeneity.
- Action potential duration was prolonged, with increased spatial dispersion and a higher incidence of alternans in diabetic atria.
- Histological analysis revealed increased interstitial fibrosis and decreased connexin 40 expression in diabetic hearts.
Conclusions:
- Diabetic atrium remodeling includes increased vulnerability to atrial tachyarrhythmia, conduction abnormalities, and altered repolarization dynamics.
- These electrophysiological changes contribute to the heightened risk of atrial fibrillation in diabetes mellitus.
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