Shockable rhythm

Shockable rhythm: Any rhythm of the heart which can be shocked back to normal using an electrical countershock with a defibrillator which delivers a high voltage direct current shock. Usual shockable rhythms are ventricular tachycardia and ventricular fibrillation. Ventricular asystole (seen as a stright line on the cardiac monitor) is not a shockable rhythm. Ventricular asystole means lack of significant electrical activity of the heart muscle and is an ominous sign.