Ventricular tachycardia & ventricular fibrillation, made clear.

VT is a fast rhythm starting in the lower chambers. It may come from a small electrical source or a circuit around scar tissue. It can reduce blood flow and may be dangerous.

A racing heartbeat with fainting, chest pain, or severe breathlessness needs emergency help.

In VF, chaotic signals make the lower chambers quiver instead of pumping blood effectively. This causes cardiac arrest.

If someone is unresponsive and not breathing normally, call 911, start CPR, and use an AED if available.

Treatment may include urgent electrical therapy, medicines, and sometimes ablation. An ICD monitors for dangerous rhythms and can deliver pacing or a shock to stop them.

Your care team also looks for and treats the underlying cause.