Human cardiac ion channels

Human cardiac ion channels are a heterogeneous group of transmembrane proteins that facilitate the movement of ions across the cell membranes of cardiomyocytes, thereby governing the electrical activity of the heart (StatPearls, 2023). These channels are categorized based on their ion selectivity—primarily sodium (Na+), potassium (K+), and calcium (Ca2+)—and are essential for the initiation, propagation, and termination of the cardiac action potential (PubMed, PMID: 28838937). Dysfunction in these channels, whether due to genetic mutations (channelopathies) or external factors, is a primary cause of cardiac arrhythmias, including Long QT syndrome and Brugada syndrome (NIH, 2022). In clinical practice, these channels serve as the primary targets for antiarrhythmic medications, which modulate ion flow to restore normal rhythm (PubChem). However, they also represent a significant safety concern in drug development, as many non-cardiovascular drugs can inadvertently inhibit channels like hERG (KCNH2), leading to life-threatening arrhythmias (FDA, 2020). Understanding the complex interplay of these channels is crucial for both therapeutic intervention and the assessment of drug-induced cardiotoxicity.

Other names

Cardiac ion channel familyHeart ion channelsVoltage-gated cardiac channelsCardiac channelome

Drugs targeting these channels typically act as pore blockers or gating modifiers, selectively inhibiting the flow of specific ions (Na+, K+, or Ca2+) during different phases of the cardiac action potential to prolong or shorten refractory periods and slow conduction velocity (StatPearls, 2023).