An electric shock applied to the heart to terminate a disturbance of its rhythm. ... (05 Mar 2000) ... 
(koun´tәr-shok″) a high-intensity direct current shock delivered to the heart to interrupt ventricular fibrillation and restore synchronous electrical activity.
(Learning Modules / Psychology / Stress) This follows the initial shock phase of the alarm reaction when blood pressure has dropped, in the countershock phase arousal in the body becomes heightened.
Type: Term Pronunciation: kown′ter-shok Definitions: 1. An electric shock applied to the heart to terminate a disturbance of its rhythm.