What is cardiac arrest?

• A. The heart has stopped working.
• B. The heart beats irregularly but continues to pump.
• C. The lungs have stopped functioning.
• D. The blood pressure is too high.

Answer: (A)

Cardiac arrest is when the heart stops pumping effectively, so blood circulation to the brain and other vital organs ceases. In this situation the person typically becomes unresponsive and stops breathing normally, and every moment without intervention lowers the chance of survival. In a dental setting, recognizing this immediately is essential because you must act fast: call for help, activate emergency services, start CPR with chest compressions, and use an AED as soon as it’s available.

If the heart were beating irregularly but still pumping, that describes a rhythm disturbance rather than cardiac arrest. If the lungs have stopped functioning, that’s a respiratory arrest, not cardiac arrest. If blood pressure is very high, that’s a hypertensive crisis, which is a different medical emergency.