Commotio cordis

Commotio cordis (Latin, ``agitation of the heart'') is an often lethal disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart (the precordial region), at a critical time during the cycle of a heart beat causing cardiac arrest. It is a form of ventricular fibrillation (V-Fib), not mechanical damage to the heart muscle or surrounding organs, and not the result of heart disease. The fatality rate is about 65% even with prompt CPR and defibrillation, and more than 80% without.

Question: can a blow to the chest stop your heart
Answer: yes