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Definition: pulmonary hypertension from The Hutchinson Unabridged Encyclopedia with Atlas and Weather Guide

In medicine, high blood pressure in the lungs due to a resistance to blood flow caused by constriction of the smaller arteries. Lung diseases, such as chronic bronchitis and emphysema, bring about pulmonary hypertension.


Summary Article: Pulmonary Hypertension
from Quick Reference to Critical Care

Emerging as one of the most underdiagnosed conditions on the medical front, pulmonary hypertension (PH) is characterized by increased pressure in the pulmonary arteries of at least double normal pressures: >25 mm Hg at rest and >30 mm during exercise. The disease process results in narrowing and stiffening of the pulmonary arterial lumen walls and causes an obstruction of blood flow, which (over time) leads to right-sided heart failure.

The New York Heart Association Functional Classification System assigns four categories to classify the extent of the resultant heart failure (see Heart Failure in Part 2), and this information is frequently used to estimate prognosis and determine eligibility for clinical trials. Symptoms of PH include dyspnea, fatigue, chest pain, tachycardia, syncope, peripheral edema, and possibly cyanosis.

While definitive diagnosis is difficult, the “gold standard” for identification is right-sided cardiac catheterization. Treatment is aimed at slowing disease progression and decreasing the workload of the heart by allowing blood to flow more easily through the pulmonary arteries. The IV drug Flolan (epoprostenon) and the IV/SQ drug Remodulin (treprostinil) are commonly used, although there are many other drugs available. More recently, the FDA has approved Tyvaso (treprostinil) Inhalation Solution for treatment, administered via a specialized inhalation system.

© 2011 Wolters Kluwer Health, Lippincott Williams & Wilkins

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