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is reflected by dilated capillaries and peripheral arteriovenous shunting, probably the result of abnormal nitric oxide and endothelin metabolism, although other factors may also play a role. The high cardiac output is achieved by an increase in both resting heart rate and stroke volume, and leads to an increased mixed venous oxygen concentration. Echocardiography typically shows mild four-chamber enlargement; this should not be interpreted as congestive heart failure. Similarly, because of the systemic vasodilation, mild hypotension (systolic blood pressure 90-100 mm Hg) is frequently seen, and again is not necessarily an indication of left ventricular dysfunction.

Coronary artery disease (CAD) should be excluded in patients with risk factors (diabetes mellitus, positive family history). In patients with limited mobility due to severe ascites or encephalopathy, dobutamine stress echocardiography may be the preferred initial preoperative test. Whether CAD is treated surgically or medically, liver transplantation in these patients carries an increased perioperative mortality rate (approximately 31%) with a 3-year mortality rate of 50%. This high mortality rate has to be considered when the decision is made to accept a patient with CAD for liver transplantation. Echocardiography has the additional advantage that overall cardiac function can be assessed and other problems can be diagnosed (pericardial effusion, valvular disease). Overall, patients with cardiac dysfunction may not tolerate the intraoperative hemodynamic changes. In addition, the increase in systemic vascular resistance after successful transplantation represents an increase in afterload for the left ventricle, and may lead to overt cardiac failure. Abnormal cardiac function may be seen in patients with hemochromatosis and alcoholic liver disease, and while this may not be apparent preoperatively at rest, a dobutamine stress echocardiography may elicit reduced cardiac reserve. Other appropriate tests in selected patients include stress electrocardiography, resting echocardiography, or stress echocardiography; cardiac catheterization may be necessary to make the final diagnosis.

Pulmonary hypertension is seen more frequently in patients with portal hypertension than in the general population for unknown reasons. Because of high perioperative mortality, liver transplantation is probably contraindicated in patients with severe pulmonary hypertension (systolic pulmonary artery [PA] pressure > 60 mm Hg, mean PA pressure > 40 mm Hg) and in patients with moderate pulmonary hypertension (systolic PA pressure 45-60 mm Hg, mean PA pressure 35-40 mm Hg) when right ventricular dysfunction is present. Screening for pulmonary hypertension is best accomplished by electrocardiography (right axis deviation, right ventricular hypertrophy, right ventricular strain), chest radiography (prominent PA), and questioning the patient for symptoms like fatigue, dyspnea on exertion, substernal chest pain, and hemoptysis. Evaluation is done by transthoracic echocardiography, and the diagnosis is confirmed by right heart catheterization.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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