pulmonary disorders
Pulmonary Hypertension
Diagnosis of Pulmonary Hypertension
Exertional dyspnea Initial confirmation: Chest x-ray, ECG, and echocardiography Identification of underlying disorder: Spirometry, ventilation/perfusion scanning or CT angiography, high-resolution CT (HRCT) of the chest, pulmonary function testing, polysomnography, HIV testing, complete blood count, liver tests, and autoantibody testing Confirmation of the diagnosis and gauging severity: Pulmonary artery (right heart) catheterization Additional studies to determine severity: 6-minute walk distance and plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) or BNP Pulmonary hypertension is suspected in patients with significant exertional dyspnea who are otherwise relatively healthy and have no history or signs of other disorders known to cause pulmonary symptoms. Patients initially undergo Chest x-ray , The most common x-ray finding in pulmonary hypertension is enlarged hilar vessels that rapidly prune into the periphery and a right ventricle that fills the anterior airspace on lateral view. Spirometry and lung volumes may be normal or show mild restriction, and diffusing capacity for carbon monoxide (DLCO) is usually reduced. Other ECG findings include right axis deviation, R>S in V1, S1Q3T3 (suggesting right ventricular hypertrophy), and peaked P waves (suggesting right atrial dilation) in lead II. Additional tests are obtained as indicated to diagnose secondary causes that are not apparent clinically. These tests can include Ventilation/perfusion scanning or CT angiography to detect thromboembolic disease HRCT for detailed information about lung parenchymal disorders in patients in whom CT angiography is not done Pulmonary function tests to identify obstructive or restrictive lung disease Serum autoantibody tests (eg, antinuclear antibodies [ANA], rheumatoid factor [RF], Scl-70 [topoisomerase I], anti-Ro (anti-SSA), anti-ribonucleoprotein [anti-RNP], and anticentromere antibodies) to gather evidence for or against associated autoimmune disorders Chronic thromboembolic pulmonary hypertension is suggested by CT angiography or ventilation/perfusion (VQ) scan findings and is confirmed by arteriography. CT angiography is useful to evaluate proximal clot and fibrotic encroachment of the vascular lumen. Other tests, such as HIV testing, liver tests, and polysomnography, are done in the appropriate clinical context. When the initial evaluation suggests a diagnosis of pulmonary hypertension, Pulmonary Artery Catheter (PAC) Monitoring is necessary to measure the following: Right atrial pressure Right ventricular pressure Pulmonary artery pressure Pulmonary artery occlusion pressure Cardiac output Left ventricular diastolic pressure Right-sided oxygen saturation should be measured to exclude left-to-right shunt through Atrial Septal Defect (ASD) . Although finding a mean pulmonary arterial pressure of Drugs that acutely dilate the pulmonary vessels, such as inhaled nitric oxide, IVepoprostenol, oradenosine, are often given during catheterization. Decreasing right-sided pressures in response to these drugs may help in the choice of drugs for treatment. Lung biopsy, once widely done, is neither needed nor recommended because of its associated high morbidity and mortality. Echocardiography findings of right heart systolic dysfunction (eg, tricuspid annular plane systolic excursion) and certain right heart catheterization results (eg, low cardiac output, very high mean pulmonary artery pressures, and high right atrial pressures) indicate that pulmonary hypertension is severe. Other indicators of severity in pulmonary hypertension are assessed to evaluate prognosis and to help monitor responses to therapy. They include a low Six-minute walk test distance and high plasma levels of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) or brain natriuretic peptide (BNP). Once pulmonary hypertension is diagnosed, the patient's family history should be reviewed to detect possible genetic transmission (eg, premature deaths in otherwise healthy members of the extended family). In familial PAH, genetic counseling is needed to advise mutation carriers of the risk of disease (about 20%) and to advocate serial screening with echocardiography. Testing for mutations in theBMPR2gene in idiopathic PAH can help identify family members at risk. If patients are negative forBMPR2, gene testing forSMAD9,KCN3, andCAV1can further help identify family members at risk. 