Changes in Strain Pattern and Exercise Capacity after Transcatheter Closure of Atrial Septal Defects

Abstract

Background and Objectives: Assessment of left ventricle (LV) function by using strain and strain rate is popular in the clinical setting. However, the use of these echocardiographic tools in assessing right ventricle (RV) failure, and the manner in which they both reflect the functional capacity of the patient, remains poorly understood. This study aimed to investigate the change in exercise capacity and strain between before and (1 month) after the transcatheter closure of atrial septal defects (ASDs). Subjects and Methods: Thirty patients who underwent transcatheter closure of ASD between May 2014 and June 2015 at the Division of Pediatric Cardiology, Severance Cardiovascular Hospital, were enrolled. We compared and analyzed the results of the following examinations, before and (1 month) after the procedure: echocardiography, cardiopulmonary exercise test (CPET), and N-terminal probrain natriuretic peptide level. Results: There were no mortalities, and the male-to-female ratio was 1:2. The mean defect size was 22.3±4.9 mm; the mean ratio of pulmonary to systemic flow, 2.1±0.5; and the mean device size, 22.3±4.9 mm. Changes in global RV longitudinal (GRVL) strain and LV torsion were measured echocardiographically. Exercise capacity improved from 7.7±1.2 to 8.7±1.8 metabolic equivalents (p=0.001). These findings correlated to the change in GRVL strain (p=0.03). Conclusion: The average exercise capacity increased after device closure of ASD. The change in strain was evident on echocardiography, especially for GRVL strain and LV torsion. Further studies comparing CPET and strain in various patients may show increased exercise capacity in patients with improved RV function.