HRS Board Review 2025 New Courses (Reviewers Copy)-Workshop 1_Tomaselli_2025

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Video Summary

In heart failure, the main observation is conduction slowing in the myocardium, primarily due to the downregulation of connexin 43, particularly in the ventricular myocardium. This downregulation not only reduces connexin 43 levels but also alters its subcellular localization, further hindering conduction. Other related changes in heart failure models include downregulation of delayed rectifier potassium currents, action potential prolongation, and changes in sodium-calcium exchanger regulation. However, connexin 43 downregulation is a key factor in conduction slowing, making it crucial for understanding heart failure's impact on cardiac conduction.

Keywords

heart failure

conduction slowing

connexin 43

ventricular myocardium

cardiac conduction