How does CPR improve a person's chance of survival during cardiac arrest?

• A. CPR keeps blood carrying oxygen flowing to the brain and vital organs.
• B. CPR cures the underlying heart condition.
• C. CPR reduces blood flow to the brain to save energy.
• D. CPR only buys time until help arrives and does not affect survival.

Answer: (A)

The main idea is that CPR creates artificial circulation to keep oxygen-rich blood moving to the brain and other vital organs during a cardiac arrest. When the heart stops beating, blood flow to the brain and organs drops rapidly, and brain cells begin to die within minutes. Chest compressions push blood through the arteries, and rescue breaths help bring oxygen into the circulating blood. This combination maintains perfusion and oxygen delivery long enough for the heart to regain rhythm or for defibrillation and advanced care to be provided, which improves survival chances. It doesn’t cure the underlying heart condition, and it isn’t only about buying time—the ongoing blood flow it sustains directly supports survival until professional help arrives.