title: Impaired exercise capacity following atrial septal defect closure: an invasive study of the right heart and pulmonary circulation.
abstract: Patients with early repair of an isolated atrial septal defect (ASD) are expected to have unremarkable right ventricular (RV) and pulmonary circulation physiology. Some studies, however, suggest persistent functional impairment. We aimed to examine the role of abnormal RV and pulmonary vascular response to exercise in patients who had undergone ASD closure. Using a previously published data set, we reviewed invasive exercise cardiopulmonary testing with right-sided hemodynamic data for 12 asymptomatic patients who had undergone ASD closure. The 5 (42%) patients with impaired maximal oxygen uptake ([Formula: see text]) were older and exhibited a lower peak cardiac index (5.6 ± 0.8 vs. 9.0 ± 1.2 L/min/m(2); P = .005) because of abnormal stroke volume augmentation (+3.2 ± 3.9 vs. +17.4 ± 10.2 mL/m(2); P = .02). While all resting hemodynamic variables were similar, patients with low [Formula: see text] tended to have abnormal total pulmonary vascular resistance change during exercise (+11% ± 41% vs. -28% ± 26%; P = .06) and had a steeper relation between mean pulmonary arterial pressure and cardiac index (5.8 ± 0.6 vs. 2.2 ± 0.1 L/min/m(2); P = .02). The increase in peak mean RV power during exercise was also significantly lower in the impaired-[Formula: see text] patients (4.7 ± 1.6 vs. 7.6 ± 2.1 J/s; P = .04). As described in the original study, despite normal resting hemodynamics, a subset of asymptomatic patients with repaired ASD had diminished exercise capacity. Our analysis allows us to conclude that this is due to a combination of abnormal pulmonary vascular response to exercise and impaired RV function.
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Cardiovascular Research and Development Unit, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Santos
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: David
authors.initials: D
authors.lastname: Systrom
authors.affiliation: MedStar Heart Institute, Washington Hospital Center, Washington, DC, USA.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Epstein
authors.affiliation: MedStar Heart Institute, Washington Hospital Center, Washington, DC, USA ; Department of Cardiology, Children's National Medical Center, Washington, DC, USA.
authors.forename: Anitha
authors.initials: A
authors.lastname: John
authors.affiliation: MedStar Heart Institute, Washington Hospital Center, Washington, DC, USA.
authors.forename: George
authors.initials: G
authors.lastname: Ruiz
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA ; Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Landzberg
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA ; Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Opotowsky
keywords: atrial septal defect; exercise; pulmonary circulation; right ventricle