Evaluation of Regional Left and Right Ventricular Function in Patients with Ostium-Secundum Atrial Septal Defect Using Speckle Tracking Echocardiography. acbr [Internet]. 2020 Jul. 14 [cited 2026 Sep. 17];4(4):274-91. Available from: https://fortunejournals.org/ojs/index.php/acbr/article/view/14770