Abstract

Heart failure is a combination of the body's compensatory mechanisms kicking in to ensure ventricular filling and adequate cardiac output of oxygenated blood to the circulatory system. These compensatory mechanisms are triggered either by sudden or chronic changes to the heart as a result of myocardial infarction (MI), coronary artery disease, hypertension, high cholesterol, diabetes, infection, or kidney and respiratory disorders. Among the compensatory mechanisms are the release of epinephrine/norepinephrine (catecholamines) by the sympathetic nervous system, which supplements cardiac output through increased muscle contractility and blood vessel constriction. Also, the secretion of antidiuretic hormone by the pituitary gland and the hormone renin by the kidneys stimulates the reabsorption of sodium and water to increase blood flow.