Heart cells (cardiac myocytes) contract due to an increase in the charge across the membrane (depolarization), which generates an action potential.

Some have provided evidence that these channels are present in human atrial cells,[8] while others have failed to find similar results.

[9] The calcium-activated chloride channel is an important component in the early phase of repolarization (bringing the charge across the membrane back to normal) of cardiac muscle cells,[10] contributing to the plateau formation during an action potential.

Blocking the calcium current reduces delayed after-depolarization amplitudes enough to prevent generation of an action potential.

[3] ACA has been shown to inhibit the calcium-activated chloride current, but this effect is reversible upon removal of the drug.