The release phase of CPR aids in filling the heart with blood.

• A. False
• B. During inhalation
• C. Not applicable
• D. True

Answer: (D)

During CPR, when the chest is released after a compression, the chest wall springs back to its normal position. This recoil creates a drop in intrathoracic pressure that acts like a suction, helping blood return to the heart from the veins. As a result, the ventricles fill more between compressions, setting up a larger amount of blood to be ejected with the next compression. This filling during the release phase is essential because it directly impacts how much blood is available to perfuse the heart and brain on the following beat. Proper chest recoil and full release maximize venous return and improve overall CPR effectiveness.