Patient selection: age > 40 years with secundum type ASD. Patients with NYHA class III or IV symptoms were excluded.
Indications for surgical closure:
(1) ratio of pulmonary output (Qp) to systemic output (Qs) >= 1.7
(2) systolic pressure of pulmonary artery < 70 mm Hg
where:
• Cardiac output is measured in liters per minute.
• A left to right shunt may occur in patients with ASD.
Surgical closure should be performed as soon as possible even if the patient's symptoms are minimal.
Factors associated with increased risk of death:
(1) medical management (associated with higher rate of sudden death)
(2) mean pulmonary artery pressure > 35 mm Hg
(3) cardiac index (stroke volume times heart rate divided by body surface area) < 3.5 liters per square meter
(4) age >= 60 years
(5) history of atrial fibrillation or atrial flutter
