Pacemaker current

Pacemaker Current is a term used in cardiology to describe the electrical impulses generated by the natural pacemaker cells in the heart. These impulses are responsible for initiating each heartbeat and maintaining a regular rhythm.

Overview

The pacemaker current, also known as the funny current or I_f, is a mixed sodium-potassium current that activates spontaneously and contributes to the automaticity of cardiac pacemaker cells. It is called the funny current because of its unusual properties, including its activation by hyperpolarization and its permeability to both sodium and potassium ions.

Function

The pacemaker current plays a crucial role in the initiation and regulation of the heart's rhythmic contractions. It is responsible for the slow, spontaneous depolarization of the pacemaker cells that leads to the generation of an action potential. This action potential then spreads to the rest of the heart, causing it to contract and pump blood.

Clinical Significance

Abnormalities in the pacemaker current can lead to various cardiac arrhythmias, including bradycardia (slow heart rate), tachycardia (fast heart rate), and atrial fibrillation (irregular heart rhythm). Drugs that modulate the pacemaker current, such as Ivabradine, are used to treat certain types of arrhythmias.

See Also

• Cardiac action potential
• Cardiac pacemaker
• Cardiac arrhythmia
• Ivabradine

References

Pacemaker current Resources
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