Cardiac Ion Channel Protein Activity

Cardiac ion channel protein activity refers to the function of specialized membrane proteins in heart cells (cardiomyocytes) that selectively allow ions—such as sodium (Na⁺), potassium (K⁺), calcium (Ca²⁺), and chloride (Cl⁻)—to flow across the cell membrane. This movement of ions is essential for generating and propagating the cardiac action potential, which underlies each heartbeat. The precise timing and coordination of these channels' opening and closing regulate cardiac excitability, contraction, rhythm, and overall electrophysiological stability. Major classes include Sodium Channels (Nav), Potassium Channels (Kv), Calcium Channels (Cav), and Chloride Channels. Activity is tightly regulated by phosphorylation, protein-protein interactions, and scaffolding. Dysfunction can cause arrhythmias or contribute to heart failure.

Modulation of ion flow across cardiomyocyte membranes.