An electric shock that is applied to the chest to restore normal rhythm of the heart.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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Historical Examples of countershock
Among them is the shock which cuts off the past and the countershock which reawakens memory.The Million Dollar Mystery