“… 21 , 22 , 25 In light of unrecognized chronic respiratory failure, some patients may present with associated polycythemia. 21 , 26 , 27 Others may exhibit diaphoresis, edema, and signs of right heart failure leading to a mistaken diagnosis of congenital heart disease. In older children and adults, pulmonary hypertension and cor pulmonale are the results from unrecognized and untreated hypoxemia and hypoventilation and may be the presenting signs.…”