What is the most common electrical rhythm disturbance that leads to sudden cardiac arrest?

Ventricular Fibrillation is the most common electrical rhythm disturbance that can lead to sudden cardiac arrest. This condition occurs when the electrical activity in the heart becomes chaotic, leading the ventricles to quiver ineffectively instead of contracting in a coordinated manner. As a result, the heart is unable to pump blood, resulting in a sudden loss of circulation and ultimately, cardiac arrest.

The chaotic nature of ventricular fibrillation means that it prevents adequate blood flow to vital organs, which can lead to rapid clinical deterioration if not treated promptly. Defibrillation is a key treatment modality for ventricular fibrillation; it aims to deliver an electric shock to the heart to restore a normal rhythm. The immediacy of this intervention underscores the critical need for quick recognition and response in cases of suspected cardiac arrest.

In contrast, while other conditions such as pulseless electrical activity and asystole are also related to cardiac arrest, they occur less frequently as the initial rhythms in cases of sudden cardiac arrest. Ventricular tachycardia can be potentially stable and may even have a pulse, making it different from fibrillation in terms of urgency and treatment approaches.