CHEST Physician

M O N T R E A L — Obese patients often have a constellation of physiological problems that together can lead to a mistaken diagnosis of pulmonary artery hypertension, according to researchers at Duke University Medical Center in Durham, N.C. The presence of exertional dyspnea in these patients often leads to an echocardiogram and a finding of elevated right ventricular systolic pressure. “Often the pressure is just mildly elevated, and these patients don’t really have pulmonary arterial hypertension but are referred for evaluation anyway,” Dr. Terry A. Fortin said at CHEST 2005, the annual meeting of the American College of Chest Physicians. To assess diagnostic strategies for pulmonary arterial hypertension (PAH) in this often very symptomatic population, Dr. Fortin and her colleagues at Duke University retrospectively assessed consecutive cardiac catheterization data on patients referred for suspected PAH. Suspected PAH was defined as mean pulmonary arterial pressure (mPAP) greater than 25 mm/Hg, pulmonary capillary wedge pressure (PCWP) less than 15 mm/Hg, and pulmonary vascular resistance (PVR) greater than 3 Wood units. Patients with left ventricular systolic dysfunction, PAH clearly associated with a known syndrome, or significant valve or lung disease of sufficient severity to explain PH were excluded. That left 78 obese patients with mild pulmonary