Rhythm is it: Ion channels ensure the heart keeps time
Friday, September 9, 2011 - 09:00
in Biology & Nature
The heartbeat is the result of rhythmic contractions of the heart muscle, which are in turn regulated by electrical signals called action potentials. Action potentials result from the controlled flow of ions into heart muscle cells (depolarization) through channels in their membranes, and are followed by a compensating reverse ion current (repolarization), which restores the original state. If the duration of the repolarization phase is not just right, the risk of ventricular arrhythmia and sudden cardiac death increases significantly.