Fig. 4.

Timeline for cellular events due to severe ischemia in myocardial tissues. Obstruction in blood flow to the heart and subsequent declines in oxygen availability and glycogen stores result in the initiation of a cascade (delineated by the arrow) of molecular, biochemical and functional events within seconds that ultimately can result in cellular death within hours. Redrawn from Ostadal and Kolar (Ostadal and Kolar, 1999). Determinate tissues including the myocardium and neurons with relatively finite growth set by birth (inset) and pulmonary alveoli set at maturity are especially vulnerable to irreversible damage with such events. Not surprisingly, these tissues have demonstrated long-term effects with COVID-19 infection.