precordial thump, a sharp, quick blow to the sternum for patients with witnessed, monitored, unstable ventricular tachycardia, including pulseless ventricular tachycardia, if a defibrillator is not immediately ready for use. Its use should not delay the initiation of cardiopulmonary resuscitation (CPR). Once taught as part of the CPR procedure, it is no longer recommended for unwitnessed cardiac arrest.
