Editing Haemodynamic response (section)

===Acute coronary syndrome===
Acute infections, such as [[community-acquired pneumonia]] (CAP), act as a trigger for [[acute coronary syndromes]] (ACS). ACS deals with symptoms that result from the obstruction of coronary [[arteries]]. Due to this obstruction there are [[thrombotic]] complications at the sites of [[atherosclerotic plaques]]. The most common symptom that prompts diagnosis is chest pain, associated with nausea and sweating. Treatment usually includes [[aspirin]], [[Clopidogrel]], [[nitroglycerin]], and if chest pain persists [[morphine]]. Recent study suggests that acute respiratory tract infection can act as a trigger for ACS. This in turn has major prothrombotic and haemodynamic effects.<ref name="sciencedirect" />

These effects result from [[coagulation]], which is normally prevented in the vascular endothelium by expression of antithrombotic factors on its surface. [[Sepsis]], which causes disruption and [[apoptosis]] of endothelial cells results in the endothelium switching to a procoagulant phenotype. This promotes platelet adhesion and aggregation. Moreover, only once disruption of the plaque surface has occurred are these prothrombotic effects likely to be significant in the pathogenesis of ACS. Sepsis is also largely associated with haemodynamic changes. Coronary artery perfusion pressure is reduced in peripheral vasodilation, which results in reduced blood pressure and reduced myocardial contractility. Endothelial dysfunction induces coronary vasoconstriction. This is caused by [[catecholamine]] release and by infections. Severe infections lead to increase myocardial metabolic demands and [[Hypoxia (medical)|hypoxia]]. When neuronal tissue is deprived of adequate oxygen, the haemodynamic response has less of an effect at active neuronal tissue. All of these disturbances increase the likelihood of ACS, due to coronary plaque rupture and thrombosis. Overall, ACS results from the damage of coronaries by atherosclerosis, so primary prevention of ACS is to prevent atherosclerosis by controlling risk factors. This includes eating healthy, exercising regularly, and controlling cholesterol levels.<ref name="sciencedirect" />