Which rhythm is considered shockable in cardiac arrest?

Ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT) are considered shockable rhythms during a cardiac arrest scenario. This is because both of these conditions indicate a severe disturbance in the heart's electrical activity, leading to ineffective pumping of blood.

In VF, the heart's electrical signals are chaotic, preventing it from contracting effectively. Similarly, in pulseless VT, the heart beats very fast and does not pump blood properly. The primary goal in these situations is to restore a normal rhythm, and defibrillation is the most effective way to achieve that by delivering an electric shock to the heart. This shock may help reset the heart's electrical system and allow it to resume a normal rhythm.

On the other hand, rhythms such as normal sinus rhythm, atrial fibrillation, and asystole do not respond to defibrillation in the same way. Normal sinus rhythm indicates a healthy heart function, while atrial fibrillation can be managed with medication rather than immediate defibrillation. Asystole represents a flatline ECG without any electrical activity, and while it indicates the absence of a heartbeat, it cannot be treated with shocks. Hence, the focus is squarely on VF and pulseless VT