Fig. 1

Pathophysiology of Changes in Free Water and Water Content During Ischemic Myocardial Injury. A simplified graphical representation of (a) equilibrium of free water and bound water during steady physiologic state. During ischemia due to micro- or macro-vascular obstruction, (b) adenosine triphosphate (ATP)-dependent ion pumps are disrupted resulting in fluid shifting intracellularly and an increase in free water relative to bound water without change in net water content. Decreased intracellular pH changes protein conformation—favoring release of bound water. Finally, reperfusion of necrotic myocardium through damaged microvasculature (c) results in leakage of intravascular fluid and cells into the interstitial space with gain of free water in this compartment and net water increase. Adapted with permission from Springer Nature: Nature Reviews Cardiology. Friedrich MG. Myocardial edema–a new clinical entity? Nat Rev Cardiol. 2010;7(5):292–296. https://doi.org/10.1038/nrcardio.2010.28