How does the LifeVest work to protect a patient's heart?

The LifeVest, a wearable defibrillator, protects a patient's heart by using electrodes that constantly monitor the heartbeat to detect life-threatening rhythmic abnormalities, according to Zoll Medical Corporation. When the device detects such a rhythm, it alerts the patient, then delivers an electrical shock to restore the normal rhythm.

If the patient is unconscious, the LifeVest releases a gel that covers the therapy electrodes before delivering the shock. Doctors prescribe the device for patients who have had, or are at risk for, a heart attack, a stent replacement, bypass surgery or congestive heart failure. The vest is a lightweight, washable garment that is designed for all-day wear, except when the patient is taking a shower or bath, notes Zoll Medical Corporation, the product's manufacturer.