Cardiac output is the amount of blood the heart pumps out the rest of the body per minute. Though the amount may change due to the demands placed on the body, resting cardiac output is 5 L/min. Cardiac output is determined by the product of stroke volume, quantity of blood ejected from the ventricles at each contraction, and heart rate.4 Heart failure occurs due to any disease or condition that does not allow the heart to maintain the proper cardiac output to match the body’s demands. Though there are many ways to classify heart failure, the best way to classify it in terms of physiology is compensated vs. decompensated. Compensated heart failure occurs when the body tries to maintain homeostasis through multiple physiological mechanisms. Tachycardia of the heart, even when stress is minimal or at rest, is the autonomic nervous system’s way of trying to increase heart rate to increase cardiac output.4 There is constriction of the veins to increase blood pressure and return more blood to the heart so it can have an increased stroke volume. There is also vasoconstriction of the arteries and redirected blood flow to vital organs as well. The kidneys will also retain fluid and sodium, which will lead to a further increase in blood pressure. All the extra work being done by the heart will cause hypertrophy of the myocardium causing the heart to require more energy to pump but also decreasing the contractility of the heart, thus decreasing stroke volume. This will make the heart have to work harder still and cause it to extract more oxygen from the oxygenated blood it receives due to its increase need for energy to support its size and workload.4 In decompensated heart failure, the heart fails to supply the kidneys the amount of oxygenated blood they require to function normally. This causes the kidneys to increase fluid retention in an
Cardiac output is the amount of blood the heart pumps out the rest of the body per minute. Though the amount may change due to the demands placed on the body, resting cardiac output is 5 L/min. Cardiac output is determined by the product of stroke volume, quantity of blood ejected from the ventricles at each contraction, and heart rate.4 Heart failure occurs due to any disease or condition that does not allow the heart to maintain the proper cardiac output to match the body’s demands. Though there are many ways to classify heart failure, the best way to classify it in terms of physiology is compensated vs. decompensated. Compensated heart failure occurs when the body tries to maintain homeostasis through multiple physiological mechanisms. Tachycardia of the heart, even when stress is minimal or at rest, is the autonomic nervous system’s way of trying to increase heart rate to increase cardiac output.4 There is constriction of the veins to increase blood pressure and return more blood to the heart so it can have an increased stroke volume. There is also vasoconstriction of the arteries and redirected blood flow to vital organs as well. The kidneys will also retain fluid and sodium, which will lead to a further increase in blood pressure. All the extra work being done by the heart will cause hypertrophy of the myocardium causing the heart to require more energy to pump but also decreasing the contractility of the heart, thus decreasing stroke volume. This will make the heart have to work harder still and cause it to extract more oxygen from the oxygenated blood it receives due to its increase need for energy to support its size and workload.4 In decompensated heart failure, the heart fails to supply the kidneys the amount of oxygenated blood they require to function normally. This causes the kidneys to increase fluid retention in an