Voltage-dependent L-type calcium channel (Cav1.2 and Cav1.3) (LTCC)

Cardiac nodal L-type calcium channels (LTCCs), primarily composed of the Cav1.2 (CACNA1C) and Cav1.3 (CACNA1D) subunits, are critical components of the cardiac conduction system (UniProt, 2024). In the sinoatrial (SA) and atrioventricular (AV) nodes, these channels facilitate the influx of calcium ions during the late phase of the pacemaker potential and the rapid upstroke of the action potential (PubMed, 2003). This activity is essential for initiating the heartbeat and regulating the speed of electrical conduction between the atria and ventricles. Dysregulation or mutations in these channels are linked to various arrhythmias, including atrial fibrillation and heart block (NIH, 2022). Pharmacologically, these channels are the primary targets for Class IV antiarrhythmic agents and calcium channel blockers used to treat hypertension and supraventricular tachycardias. By modulating calcium entry, these drugs can effectively slow the heart rate and control rhythm disturbances (StatPearls, 2023).

Other names

L-type calcium channelCav1.2Cav1.3CACNA1CCACNA1DDihydropyridine-sensitive calcium channelCardiac nodal calcium channel

Inhibition of L-type calcium channels reduces the influx of calcium ions into cardiac nodal cells, slowing the rate of spontaneous depolarization in the sinoatrial node and delaying conduction through the atrioventricular node (StatPearls, 2023).