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Cardiac Arrhythmias: Difference between revisions
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→Phase 2: Plateau
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===Phase 2: Plateau=== | ===Phase 2: Plateau=== | ||
The plateau phase represents an equal influx and efflux of ions producing a stable membrane potential. The influx is mediated by 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. The efflux is the result of outward current carried by K<sup>+</sup> (I<sub>Kr</sub> and Cl<sup>-</sup> ions. | The plateau phase represents an equal influx and efflux of ions producing a stable membrane potential. This plateau phase is predominantly observed in the ventricular action potential. The influx is mediated by 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. The efflux is the result of outward current carried by K<sup>+</sup> (I<sub>Kr</sub> and Cl<sup>-</sup> ions. | ||
===Phase 3: Final Rapid Repolarization=== | ===Phase 3: Final Rapid Repolarization=== | ||