**8.2 Pulmonary hypertension and Cor pulmonale**

Both resting and exercise mean pulmonary arterial pressures may be elevated. Prolonged pulmonary hypertension can give rise to chronic cor pulmonale in late stages. Alveolar hypoxia, respiratory acidosis, remodeling of the pulmonary vasculature with medial hypertrophy of muscular pulmonary arteries, increased viscosity of blood due to erythrocytosis, increased blood volume, left ventricular dysfunction and chronic pulmonary thromboembolic disease can all contribute to the pulmonary hypertension(Farber et al.,1982;Fletcher et al,1989 as cited in Shapiro SD,2010). Correction of hypoxia and acidosis by long-term oxygen therapy and pulmonary vasodilators may slow this process.
