Cardiac calcium and potassium channels

Cardiac calcium and potassium channels are a heterogeneous group of transmembrane proteins that orchestrate the electrical activity and mechanical contraction of the heart (NIH, 2022). Calcium channels, predominantly the L-type (Cav1.2), allow the influx of calcium ions during the action potential plateau, triggering calcium-induced calcium release from the sarcoplasmic reticulum to initiate muscle contraction (Frontiers, 2022). Potassium channels, including the rapid (IKr) and slow (IKs) delayed rectifiers and the inward rectifier (IK1), are responsible for repolarizing the cell and maintaining the resting membrane potential (Physiology.org, 2016). Dysfunctions in these channels, whether due to genetic mutations (channelopathies) or structural remodeling, are central to the pathogenesis of various cardiovascular diseases, such as arrhythmias, hypertension, and heart failure (NIH, 2022; ResearchGate, 2022). Pharmacological agents targeting these channels are widely used in clinical practice; calcium channel blockers (e.g., verapamil, amlodipine) are primary treatments for hypertension and angina, while potassium channel blockers (e.g., amiodarone, dofetilide) serve as potent anti-arrhythmic therapies (Healthline, 2024; NIH, 2022). However, these drugs carry significant safety risks, most notably the potential for pro-arrhythmia and life-threatening Torsades de Pointes, often associated with unintended inhibition of the hERG potassium channel (Strong Medicine, 2017).

Other names

Cardiac ion channelsVoltage-gated cardiac calcium and potassium channelsMyocardial ion channels

Drugs targeting these channels typically act as pore blockers or allosteric modulators that inhibit or enhance the flow of ions (Ca2+ or K+) across the sarcolemma, thereby altering the electrical excitability and contractile force of the myocardium.