Pulmonary vascular resistance as assessed by bicycle stress echocardiography in patients with atrial septal defect type secundum

Abstract

Background-Volume overload of the pulmonary circulation in patients with atrial septal defect (ASD)-type secundum causes pulmonary vascular disease over a long period of time. This study aimed at (1) evaluating pulmonary vascular resistance (PVR) and (2) investigating the relation between PVR and exercise capacity in patients with open and closed ASD. Methods and Results-Forty-six patients with ASD-type secundum (18 open, 28 closed) and 20 age-matched controls were enrolled. All underwent standard and symptom-limited bicycle stress echocardiography and cardiopulmonary exercise testing. PVR was calculated as the slope of a pulmonary artery systolic pressure (PAP)-flow plot or as the ratio of ..