Cause of central cyanosis include all the following except
Chronic asthma
Congestive pulmonary stenosis
Congestive hea failure
Alveolar hypotension
CHF is a cause for peripheral cyanosis and not central cyanosis. Cyanosis when present in asthma,pulmonic stenosis and alveolar hypoventilation is of central type. Ref Harrison 19th edition pg 249
Respiratory system