Vascular changes after cardiopulmonary bypass and ischemic cardiac arrest: roles of nitric oxide synthase and cyclooxygenase

Abstract

Cardiac surgery involving ischemic arrest and extracorporeal circulation is often associated with alterations in vascular reactivity and permeability due to changes in the expression and activity of isoforms of nitric oxide synthase and cyclooxygenase. These inflammatory changes may manifest as systemic hypotension, coronary spasm or contraction, myocardial failure, and dysfunction of the lungs, gut, brain and other organs. In addition, endothelial dysfunction may increase the occurrence of late cardiac events such as graft thrombosis and myocardial infarction. These vascular changes may lead to increased mortality and morbidity and markedly lengthen the time of hospitalization and cost of cardiac surgery. Developing a better understanding of the vascular changes operating through nitric oxide synthase and cyclooxygenase may improve the care and help decrease the cost of cardiovascular operations. Correspondence

Microvascular dysfunction following cardioplegic arrest and cardiopulmonary bypass

“…COX2 expression increases during reperfusion following CP/CPB in a variety of vascular beds, including coronary, cerebral, and pulmonary circulation. This observed effect is consistent with the principle of inflammation-induced changes in vascular endothelial cells [87,88] . Meanwhile, COX1 levels remain unchanged.…”

Myocardial protection by interferon-γ late preconditioning during cardiopulmonary bypass-associated myocardial ischemia-reperfusion in pigs

“…The impact of the important signaling molecule nitric oxide (NO) in cardiomyocytes during myocardial ischemia and reperfusion has resulted in conflicting reports of protective, deleterious, or null effects (32). Since NO is generated from L-arginine by nitric oxide synthase (NOS), levels of endothelial NOS (eNOS), neuronal NOS (nNOS), and inducible NOS (iNOS) can be examined to draw conclusions about cellular NO levels.…”

Effects of different levels of positive airway pressure on breathing pattern and heart rate variability after coronary artery bypass grafting surgery

“…These modifications after CABG can be related to the acute effects of surgery, with injuries to the autonomic nerve fibers or to the sinus node, and to the effects of anesthesia, surgical stress, pain, myocardial ischemia, and medications, as well as the effects of extracorporeal circulation, which is not a benign intervention and is associated with large numbers of adverse consequences (1,34).…”