Congestive heart failure is a very common disease. While many other forms of heart disease have become less common, heart failure has been increasing. Congestive heart failure has become the most common diagnosis in the hospital for patients over 65 years of age.Diastolic heart failure accounts for up to 40% of patients with congestive heart failure and is associated with a better prognosis as compared to patient with systolic dysfunction (Arora, Krummerman, Vijayaraman, Rosengarten, Suryadevara, Lejemtel, and Ferrick, 2005). Congestive heart failure occurs when the flow of blood from the heart (cardiac output) decreases, or fluid backs-up behind the falling ventricle. The comparison of the different types of congestive heart failure and what happens in the heart are unilateral, directional, time dependent, phasic, and output vs. emand heart failure. The heart is basically two pumps in one. The right side of the heart and the left side of the heart can fail independently of the other. Unilateral heart failure is this type of heart failure. Left sided heart failure is when the left ventricle cannot pump out enough blood and it gets backed-up in the lungs. A buildup of fluid in the lungs, called pulmonary edema, can cause shortness of breath and often leading to right sided heart failure.Right sided heart failure is when the right ventricle cannot pump out enough blood, causing fluid to back up in the vein and capillaries. The backup of fluid leaks out and builds up in the tissue, a condition called systemic edema. The edema is commonly noticed in the lower half of the body. Directional heart failure has two types as well. Backwards heart failure is when the ventricle is not pumping out all the blood that comes through it. The increase in the ventricle filling pressure causes pulmonary edema.The heart only meets the needs of the body if the ventricle filling pressure is high. Forward heart failure is when the heart is not pumping out enough blood to meet the needs of the body. Therefore less blood reaches the kidneys and they conserve salt and water. The conservation then leads to excess fluid retention and edema. The excess fluid then decreases the blood flow to various organs, causing weakness and fatigue. Another type of heart failure is time-dependent heart failure. Acute heart failure is heart failure that occurs suddenly.A myocardial infarction can cause a large enough part of the heart muscle to die. The heart cannot pump out enough blood when enough of the heart muscle is damaged causing pulmonary edema. The damage and pulmonary edema can make it very difficult to breath and may even lead to death. When a heart valve suddenly stops functioning or if the muscle that helps the valve function properly suddenly ruptures, causing an acute heart failure. Chronic heart failure develops gradually. The symptoms are noticed slowly at first and then become acute over time.Phasic heart failure is when the heart can fail in either of the two phases of the cardiac cycle. The contraction phases is called systole and the rest phase is called diastole. Systolic heart failure is when the heart has difficulty contracting and pumping out enough blood. Systolic heart failure causes weakness, fatigue, and decreased ability to exercise. Diastolic heart failure is when the heart is unable to fill properly during diastole. Diastolic heart failure causes systemic or pulmonary edema or both.Patients with diastolic dysfunction tend to be elderly and female and often have a long history of hypertension, although few have a history of myocardial infarction (Albrecht, Giesler, Kar, Hariharan, and Delgado, 2004). The final diagnosis classification is output vs. demand heart failure. High output heart failure is when cardiac output is normal or slightly higher, but the demand for blood flow is abnormally high. Hyperthyroidism, anemia, and severe infections are some causes of high output heart failure. The heart is unable to deliver the increased amount of blood and fails.Low output failure is when cardiac output is low, but the demand for blood flow is normal. The heart is unable to meet the demand and fails. Low output failure is more common than high output failure. The purpose of the heart is to pump blood to the rest of the body. Congestive heart failure is simply the failure of the heart to perform this main function. A lack of blood pumped to the body is only considered congestive heart failure if the heart actually receives a sufficient volume of blood from the incoming vessels.