Pathophysiology, Diagnosis, and Management of Pulmonary Hypertension in Infants and Children

Abstract

Pulmonary hypertension (PH) may occur as a primary process or as a complication of several diseases. In the pediatric population, PH secondary to congenital heart disease, chronic hypoxemia, or acute respiratory failure is more common than primary PH. Regardless of etiology, PH may lead to significant morbidity or mortality as a consequence of right-to-left shunting across cardiovascular channels or right heart failure. In this review, PH is defined in terms of the determinants of pulmonary blood flow: pulmonary artery pressure, downstream pressure, and pulmonary vascular resistance. Research addressing both normal developmental changes in pulmonary vascular resistance and abnormal pulmonary vascular reactivity is then reviewed, followed by a discussion of the etiologies of PH in children. Some of the more common clinical presentations of PH are presented focussing on the differences seen between patients with and without intracardiac communications. Assessment of the severity of PH using both noninvasive (electrocardiogram, echocardiogram, magnetic resonance imaging) and invasive (cardiac catheterization, lung biopsy) techniques is then discussed. Treatment of PH is presented, focussing on restoration of adequate pulmonary blood flow through use of both conventional and newer vasodilator therapies. The review concludes by noting the limits to our understanding of the pathogenesis and therapy of PH.