What is the effect of CPR before shocking the heart?
Evidence indicates that an electrical shock applied early after cardiac arrest helps restart the heart so that common practice has set the shock as the first priority when trying to restart the heart. When a shock is given to the heart during cardiac arrest, it resets the abnormal heart rhythm but does not necessarily start blood circulating again. Some more recent evidence indicates that delaying the shock to provide CPR may provide a better chance for the heart to regain its own natural heart beat. CPR seems to fill the heart with oxygen-rich blood so that when the heart rhythm is reset with the shock, normal circulation can be restored. This circumstance may be especially the case if the patient has been collapsed for more than five minutes. But we don’t know for sure which way of doing CPR is better.
