external pacemaker [L, externus, outward, passus, step; ME, maken, to make] , 1. a device used to stimulate the heartbeat electrically by means of impulses conducted through the chest wall, as used in emergency care of significant bradyarrhythmias. 2. a device in which the impulse generator is outside the chest but is connected with the heart by wires that pass under the skin. The wires are placed during a surgical procedure and are removed after surgery, when the risk of bradycardia has diminished.
