This sqadia.com short video clip is the brief explanation of Calcium Channel Blockers.
Calcium channels regulate the influx of calcium into muscle cells, which in turn stimulates intracellular calcium release, and contraction of smooth muscle and cardiac myocyte. Calcium channel blockers stabilizes the inhibitory calcium channels, block the entry of calcium hence causing a marked decrease in transmembrane calcium current. In smooth muscle it prevents formation of myosin and actin. In cardiac muscle it results in reduction in contractility throughout the heart.