If an AED advises a shock to a 90-year-old male in cardiac arrest, what rhythm is likely present?

When an Automated External Defibrillator (AED) advises a shock, it typically indicates the presence of a shockable rhythm. Ventricular fibrillation is one of the primary rhythms that can lead to cardiac arrest and is characterized by disorganized electrical activity in the ventricles, preventing them from contracting effectively. This chaotic rhythm is often recognized by an AED and is the primary target for defibrillation.

The elderly male in this scenario is likely in a state of cardiac arrest associated with ventricular fibrillation, which necessitates rapid intervention to restore a normal rhythm and improve the chances of survival. The AED's analysis of the heart rhythm determines whether it is safe to deliver a shock, and in cases of ventricular fibrillation, a shock is indicated to reset the heart’s electrical activity.

In contrast, rhythms like atrial fibrillation, paroxysmal supraventricular tachycardia, and Wolff-Parkinson-White syndrome are generally not shockable. Atrial fibrillation is an irregular rhythm that does not produce the chaotic electrical activity seen in ventricular fibrillation. Paroxysmal supraventricular tachycardia is a rapid heart rate originating above the ventricles, and Wolff-Parkinson-White syndrome is characterized by