[Alterations of after depolarization and triggered activity in myocardiac muscle during progression of mouse aortic stenosis]
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Updated: Apr 23, 2026
Ultrasonic Assessment of Myocardial Microstructure
Published on: January 14, 2014
Objective:
To explore the alterations of after depolarization and triggered activity in myocardiac muscle during progression of mouse aortic stenosis.
Methods:
After the establishment of mouse aortic stenosis model, the heart was collected and intracellular potential was recorded using standard glass microelectrode. After the recording, the action potential (AP), early after depolarization (EAD), delayed after depolarization (DAD) in papillary muscles were analysed.
Results:
(1) Compared with that of time-matched control mice, there were no changes of the action potoutial duration at 90% repolarization(APD90) in model mice at 2 and 5 weeks, whereas the APD90 was progressively prolonged at 9 and 13 weeks. (2) During the 30 minites of the experiment, spontaneous EADs and DADs were frequently present in medel mice at 9 and 13 weeks, were not in control and model mice at 2 and 5 weeks. (3) Compared with those of control group, EADs and DADs triggered by hypokalaemia or isoproterenol were increased significantly. The incidence rate of triggering EADs and DADs was progressively increased over time.
Conclusion:
EAD, DAD and trigger activities increase gradually during the process of aortic stenosis, and it suggests that the myocardium electrical-instability is markedly increased in the insult hearts.
