What is the purpose of cardioplegia?

• A. To cool the body to preserve temperature.
• B. To decrease heart rate during surgery.
• C. To dissolve clots in coronary arteries.
• D. To cause intentional arrest of the heart to provide a still field for operation and prevent myocardial ischemia by decreasing the O2 needs.

Answer: (D)

Cardioplegia is used to protect the heart during bypass by stopping its activity and lowering its metabolic demands. By delivering a cardioplegic solution into the coronary circulation, the heart is made quiescent, giving a still field for precise surgery while dramatically reducing oxygen consumption and preserving myocardial energy stores. Cold temperatures used with cardioplegia further slow metabolism, enhancing protection during the period the heart is cross-clamped. This focus on intentional heart arrest and myocardial protection distinguishes it from simply cooling the body or lowering heart rate, and it isn’t about dissolving clots.