Cardiac muscle cell contraction

Cardiac muscle cell contraction refers to the process by which heart muscle (cardiomyocyte) contracts in response to an electrical stimulus. This involves excitation-contraction coupling, where an action potential triggers the opening of voltage-gated L-type calcium channels in the cell membrane, allowing calcium influx, which triggers further calcium release from the sarcoplasmic reticulum via ryanodine receptors. The resulting rise in cytosolic calcium binds to troponin-C, causing conformational changes that allow actin-myosin crossbridge cycling and muscle contraction. After contraction, calcium is resequestered into the sarcoplasmic reticulum or extruded from the cell to enable relaxation.

Other names

Cardiac muscle contractionMyocardial contractionExcitation-contraction coupling (in cardiac muscle)

Modulating ion channel activity (e.g., L-type Ca²⁺ channels, Na⁺ channels, K⁺ channels); Modulating adrenergic signaling (through GPCRs); Altering intracellular calcium homeostasis; Influencing actin-myosin crossbridge cycling