Cardiac Arrhythmias: Difference between revisions

Line 20: Line 20:


===Phase 2: Plateau===
===Phase 2: Plateau===
The plateau phase represents an equal influx and efflux of ions in or out of the cell producing a stable membrane potential. This plateau phase is predominantly observed in the ventricular action potential. The inward movement of Ca<sup>2+</sup> through the open L-type Ca<sup>2+</sup> channels (I<sub>Ca-L</sub>) and the exchange of Na<sup>+</sup> for internal Ca<sup>2+</sup> by the Na<sup>+</sup>/Ca<sup>2+</sup> exchanger (I<sub>Na,Ca</sub>) are responsible for the influx of ions during the plateau phase. The efflux of ions is the result of outward current carried by K<sup>+</sup> (I<sub>Kur</sub> and <sub>Ks</sub>) and Cl<sup>-</sup> ions.
The plateau phase represents an equal influx and efflux of ions in or out of the cell producing a stable membrane potential. This plateau phase is predominantly observed in the ventricular action potential. The inward movement of Ca<sup>2+</sup> through the open L-type Ca<sup>2+</sup> channels (I<sub>Ca-L</sub>) and the exchange of Na<sup>+</sup> for internal Ca<sup>2+</sup> by the Na<sup>+</sup>/Ca<sup>2+</sup> exchanger (I<sub>Na,Ca</sub>) are responsible for the influx of ions during the plateau phase. The efflux of ions is the result of outward current carried by K<sup>+</sup> (I<sub>Kur</sub> and <sub>Ks</sub>).


===Phase 3: Final Rapid Repolarization===
===Phase 3: Final Rapid Repolarization===
585

edits