Pulmonary hypertension is considered present when the mean PA pressure is greater than 25 mm Hg at rest or 30 mm Hg during exercise.

Etiology and Classification

• Secondary pulmonary hypertension is present when there is a identifiable cause with hemodynamic sequelae leading to pulmonary hypertension. Disease of the left heart, pulmonary embolism, chronic hypoxemia and left to right shunts are common etiologies.
• Primary pulmonary hypertension is obviously idiopathic. However, it is often associated with cirrhosis , AIDS and can be familial.

Pathology

Clinical Features

• Primary pulmonary hypertension often occurs in young females. Dyspnea on exertion, fatigue, syncope, dizziness, edema and angina occur during the course of illness.
• Loud pulmonary component of the second heart sound, pulmonary ejection click, RV lift, S4 gallop, syst murmur of tricuspid regurgitation and a diastolic murmur of pulmonary regurgitation can be recognized. Findings are subtle and the diagnosis is often missed.
• Complex testing is often required to establish the presence of pulmonary hypertension and to rule out secondary causes.

Therapy

• Prognosis is poor and five year survival is between 22-33%.
• See cor pulmonale for therapeutic measures for secondary pulmonary hypertension.
• Anticoagulation, Calcium channel blocks, Nitric oxide and Prostacyclin are current therapeutic options.
• Anticoagulation has to given indefinitely.
• 20-35 % of patients respond to vasodilators acutely and benefit from their use.
• Infusion of prostacycline, continuously and chronically, improves hemodynamics, symptoms and survival. This requires implantation of a permanent central venous catheter, use of an external portable infusion pump and comprehensively trained support staff.
• Lung transplant is an option for patients refractory to medical management.