SECONDARY PULMONARY HYPERTENSION

Course overview

IN HEALTHY INDIVIDUALS, THE PULMONARY CIRCULATION IS A LOW-RESISTANCE, LOW-PRESSURE SYSTEM THAT ALLOWS DEOXYGENATED BLOOD IN THE RIGHT SIDE OF THE HEART TO PASS THROUGH THE LUNGS, WHERE THE BLOOD BECOMES OXYGENATED BEFORE ENTERING THE LEFT SIDE OF THE HEART. THE MEAN PULMONARY VASCULAR PRESSURE IS NORMALLY BETWEEN 10 AND 18 MILLIMETERS MERCURY (MM HG) AND DURING EXERCISE, THIS LOW-PRESSURE CIRCULATION CAN ACCOMMODATE HIGH BLOOD FLOW. THE RESISTANCE IN THE PULMONARY VASCULATURE DEPENDS ON THE PRESSURE IN THE PULMONARY ARTERIES, THE LEFT ATRIAL PRESSURE, AND THE CARDIAC OUTPUT. AN INCREASE IN PULMONARY RESISTANCE FROM ANY CAUSE OF INCREASED PULMONARY ARTERY PRESSURE CAN LEAD TO PULMONARY HYPERTENSION, WHICH IS A PERSISTENT ELEVATION IN THE MEAN PULMONARY ARTERIAL PRESSURE TO OVER 25 MM HG AT REST OR OVER 30 MM HG DURING EXERCISE OR CARDIAC CATHETERIZATION. PULMONARY HYPERTENSION IS CLASSIFIED AS IDIOPATHIC OR PRIMARY WHEN THE CAUSE IS UNKNOWN. WHEN PULMONARY HYPERTENSION RESULTS FROM KNOWN RISK FACTORS OR UNDERLYING DISEASES, IT IS CLASSIFIED AS SECONDARY PULMONARY HYPERTENSION. HEART AND LUNG DISEASE ARE THE MOST COMMON CAUSES OF SECONDARY PULMONARY HYPERTENSION. THIS ACTIVITY ILLUSTRATES THE EVALUATION, TREATMENT, AND COMPLICATIONS OF SECONDARY PULMONARY HYPERTENSION AND THE IMPORTANCE OF AN INTERPROFESSIONAL TEAM APPROACH TO ITS MANAGEMENT.