Pulmonary hypertension in chronic respiratory diseases The 6-minute walk test: technical and utility in functional diagnosis, prognosis and monitoring

Lung diseases can cause pulmonary hypertension (PH). The current classification of PH includes these diseases in group 3 as PH due to lung disease and/or hypoxia. This cause of PH is responsible for about 10% of all PH. Generally, the PH is often of moderate degree although a small percentage may have severe pulmonary hypertension. In the advanced stages of the disease is higher prevalence of PH. The diagnosis of lung disease and/or hypoxia is made by clinical history and complementary exams help mainly pulmonary function tests, diagnostic imaging, especially computed tomography high resolution and ventilation perfusion scintigraphy as a screening test for pulmonary arterial hypertension (PAH) due to chronic pulmonary thromboembolism (group 4). The use of an adequate algorithm allows through pulmonary function tests arrive at diagnoses pathophysiological great accuracy. Moreover, suspecting PH, the use of screening tests, group identification, assessment of exercise capacity and cardiac catheterization allows discriminating between different groups and arriving at a proper diagnosis. The 6-minute walk test is one of the essential elements in the assessment of PH, not only for comparison before and after treatment, but also to evaluate the functional capacity and as a predictor of morbidity and mortality. Its implementation requires observing guides available, respecting the absolute and relative contraindications and following established procedures worldwide. The data obtained should express the distance walked, the presence or absence of desaturation during it the evaluation perceived effort (Borg scale), the reason for arrest and heart rate. These data are part of the prediction of morbidity and mortality and are a prognostic factor the disease. The 6-minute walk test is also part of the monitoring studies in each of the stages of the clinical management of pulmonary arterial hypertension.