Moderate pre-cordial mechanical impact can cause sudden cardiac death, even in 
the absence of morphological damage to the heart. This is the most severe 
expression of a condition termed, in the 19th century, Commotio cordis. 
Experimental studies performed in the early 1930s showed that sudden cardiac 
death after chest impact is brought about by an intrinsic cardiac response to 
the mechanical stimulus. The precise (sub-)cellular mechanisms of this response 
are still poorly understood. This article summarises experimental findings on 
the condition and relates them to the more recently established concept of 
cardiac mechano-electric feedback. As a result, an explanation of the mechanisms 
that give rise to sudden cardiac death by Commotio cordis and targets for 
further research are suggested.