Pre- and postoperative exercise capacity associated with hemodynamics in adult patients with atrial septal defect: A retrospective study

Objective: This study evaluated the pre- and postoperative exercise capacity in adult patients with atrial septal defect (ASD) associated with hemodynamic variables. Methods: Adults (70) with ASD underwent symptom-limited exercise tests. Peak O₂ uptake (Peak VO₂) and % peak VO₂, that is the percentage of predicted value, were measured. These patients were divided into three groups according to pulmonary-to-systemic flow ratio (Qp/Qs) and systolic pulmonary arterial pressure (PAs); Group A: Qp/Qs3, PAs50 mm Hg, Group B: Qp/Qs>3, any PAs, Group C: Qp/Qs3, PAs>50 mm Hg. Exercise test was repeated in 22 patients after surgical closure of ASD (mean 4.6±2.0 months). Results: Peak VO₂ was significantly lower in group B (P<0.01) and group C (P<0.01) than in group A (19.3±5.7, 17.6±3.6, 27.6±6.3 ml/min/kg, respectively). In patients except those in group C, there were a weak negative correlation between PAs and % peak VO₂ (r=0.61) and a significant negative correlation between Qp/Qs and % peak VO₂ (r=0.86). Postoperative peak VO₂ increased significantly in group A (27.2±5.1–31.1±5.1 ml/min/kg, P<0.05) and group B (16.7±3.3–21.5±2.1 ml/min/kg, P<0.01). However, there was no significant difference between pre- and postoperafive peak VO₂ in group C (16.8±1.3–17.8±2.8 ml/min/kg, NS). Conclusions: In ASD patients except those with small or moderate left-to-right shunt and high pulmonary arterial pressure, there was a significant negative correlafion between Qp/Qs and peak VO₂ corrected by age and gender. Patients with large left-to-right shunt and/or high pulmonary arterial pressure had reduced exercise capacity. However, exercise capacity in patients with large left-to-right shunt increased after closure of ASD regardless of whether they had high pulmonary arterial pressure.