CVP Myocardial Protection and Cardioplegia Flashcards

Warm blood cardioplegia is delivered at approximately what temperature?

Answer: 37°C

Warm blood cardioplegia is delivered at normothermia (approximately 37°C) to maintain aerobic metabolism while the heart is arrested.

What is the primary advantage of Del Nido cardioplegia over traditional formulations?

Answer: It allows a single dose to provide 60–90 minutes of cardiac arrest

Del Nido cardioplegia is a single-dose, crystalloid-based formulation designed to maintain arrest for 60–90 minutes, reducing re-dosing interruptions.

What is the purpose of adding magnesium to cardioplegia solution?

Answer: To provide membrane stabilization and reduce calcium-mediated injury

Magnesium acts as a physiologic calcium antagonist, stabilizing cell membranes and reducing calcium overload during ischemia.

How often is cardioplegia typically re-dosed during prolonged cardiac arrest with intermittent technique?

Answer: Every 20–30 minutes

Intermittent cardioplegia is re-dosed every 20–30 minutes to replenish protective concentrations washed out by non-coronary collateral flow.

Retrograde cardioplegia is preferred over antegrade delivery in which clinical situation?

Answer: Severe aortic regurgitation

In severe aortic regurgitation, antegrade cardioplegia leaks back into the left ventricle rather than perfusing the coronaries, making retrograde delivery more reliable.

What does the term 'hot shot' refer to in cardioplegia delivery?

Answer: A warm blood reperfusate delivered just before aortic cross-clamp removal

A 'hot shot' is a terminal warm blood cardioplegia dose delivered before removing the cross-clamp to restore aerobic metabolism and wash out ischemic metabolites.