Final answer:
Antegrade cardioplegia is the administration of a cardioplegic solution into the coronary arteries during procedures like MIDCAB to cause controlled cardiac arrest. It allows the heart to stop beating for the duration of surgery, providing a motionless field for the surgeons.
Step-by-step explanation:
Antegrade cardioplegia is administered during Coronary Artery Bypass Grafting (CABG) procedures such as MIDCAB (Minimally Invasive Direct Coronary Artery Bypass) to protect the heart muscle during surgery. It involves the infusion of a cardioplegic solution directly into the coronary arteries to cause cardiac arrest in a controlled fashion. By adding potassium chloride (KCl) to the blood, the solution increases the extracellular potassium concentration, which leads to depolarization of cardiac cells and cessation of cardiac activity.
This process allows surgeons to operate on a still and bloodless field, reducing the risk of damage while they perform the procedure. Antegrade cardioplegia is especially useful in procedures like MIDCAB, where surgeons operate through smaller incisions and require a clear, motionless operative field.