In a cardiac emergency, what is the most critical action to take after calling for help?

In a cardiac emergency, starting chest compressions immediately is the most critical action after calling for help. This is because high-quality chest compressions are essential for maintaining blood flow to vital organs, especially the brain and heart, until advanced medical help arrives. Chest compressions effectively circulate oxygen-rich blood, which is crucial in minimizing brain damage and increasing the chances of survival.

Time is of the essence in a cardiac emergency, and initiating compressions promptly can significantly improve outcomes. The American Heart Association emphasizes that bystander CPR can double or triple a victim's chance of survival. Thus, the patency of the airway and the need for ventilation, checking vital signs, or offering any substances, such as water, are secondary actions that do not address the immediate need for circulation.