Med Sci Monit 1996; 2(2): HY227-232
Disorders in ionic transport across the cell membrane of cardiomyocytes leading to abnormalities in the impulse generation and propagation may be a cause of ventricular dysrhythmia. The adenosine triphosphatase-dependent sodium-potassium pump (Na+ K+,-ATPase) and cyclic adenosine monophosphate (cAMP) play an important role in this transport. Na+, K+,-ATPase is responsible for extrusion of three sodium cations from the cell in exchange for two potassium cations brought into the cytosol, thus creating a negative membrane potential. The part played by cAMP in the transmembrane ionic transport consists of, essentially, an increase in calcium influx into the cell and, to a lesser extent, potassium and a decrease in sodium influx, as a result of the phosphorylation of appropriate ion channels catalyzed by protein kinase.
Keywords: K+ -adenosine triphosphatase, cyclic adenosine monophosphate, Propafenone, metoprolol, amiodarone, Na+, ventricular arrhythmias