Editing Cardiopulmonary bypass (section)

===Cardioplegia===
{{main|Cardioplegia}}
Cardioplegia is a fluid solution used to protect the heart during CPB. It is delivered via a cannula to the opening of the coronary arteries (usually by way of the aortic root) and/or to the cardiac veins (by way of the coronary sinus).<ref name=":0" /> These delivery methods are referred to '''antegrade''' or '''retrograde''', respectively. Cardioplegia solution protects the heart by arresting, or stopping the heart. This then decreases the heart's metabolic demand. There are multiple types of cardioplegia solutions, but most work by inhibiting [[Sodium channel|fast sodium currents]] in the heart, which prevent conduction of the [[action potential]]. Other types of solutions act by inhibiting calcium's actions on [[myocyte]]s.<ref name=":2">{{Cite book |title=TSRA Primer of Cardiothoracic Surgery |vauthors=Youssef SJ, Williams JA |publisher=TSRA/TSDA |year=2013 |isbn=978-0-9894023-0-9 |location=Chicago, IL}}</ref>