CHAPTER 24 Pulmonary Hypertension
Pulmonary hypertension (PH) is a haemodynamic and pathophysiological state that can be found in multiple clinical conditions which have been classified into six diagnostic groups with specific histological, clinical, and therapeutic features. Despite possible comparable elevations of pulmonary pressure in the different clinical groups, the underlying mechanisms, the diagnostic approaches, and the prognostic and therapeutic implications are completely different.Group 1, defined as pulmonary arterial hypertension (PAH), includes rare conditions which share comparable clinical and haemodynamic pictures and virtually identical pathological changes in the lung microcirculation. PAH comprises the idiopathic and familial forms and the forms associated with connective tissue diseases, congenital heart defects with systemic-to-pulmonary shunts, portal hypertension, and human immunodeficiency virus (HIV) infection. A sequential diagnostic approach is suggested to identify and characterize the different types. Three classes of drugs (prostanoids, endothelin-receptor antagonists, phosphodiesterase type-5 inhibitors) have proven to be effective in this severe condition and an evidence-based treatment algorithm is presented. Specific clinical and therapeutic characteristics of each PAH type are also discussed. Lung transplantation is indicated in case of medical treatments failure.
Group 2 includes patients with PH due to left heart disease. In these cases the treatment is addressed to the underlying heart condition and specific medications approved for PAH have not proven to be convincingly effective.
Group 3 includes cases of PH due to lung diseases in which the use of specific medications approved for PAH is not recommended on the basis of their minimal clinical efficacy and because they may impair pulmonary gas exchange.
Group 4 comprises patients with chronic thromboembolic PH where treatment of choice is pulmonary endarterectomy, and group 5 includes a miscellanea of rare conditions.
Chapter 28)
