Evaluation of the Ventricular Mechanical Dyssynchrony in Patients with Atrial Septal Defect

Background: There is some evidence indicating improvement in myocardial performance after atrial septal defect closure, either device closure or surgical, but ventricular dyssynchrony has not been evaluated before and after surgical closure. The aim of this study was to evaluate ventricular mechanical dyssynchrony in patients with atrial septal defect before and after surgical closure. Methods: Twenty patients (mean age: 23±11years) with isolated secundum or sinus venosus type atrial septal defect, unsuitable for device closure, were evaluated before and after successful surgical closure. Interventricular and intraventricular dyssynchrony (using 6 basal and 6 mid-segmental models) were determined. Results: A significant reduction in the right atrial and right ventricular dimensions and the tricuspid regurgitation peak gradient was noted after atrial septal defect closure (3.6±0.54 cm versus 4.2±0.7, P=0.009; 3.5±0.29 cm versus 4.3±0.41, P=0.02; and 20.4±10.5 mmHg versus 35.3±6.5, P<0.002; respectively). There was no significant difference in the maximum difference in time-to-peak systolic velocity and the standard deviation of time-to-peak systolic velocity of the l2 left ventricular myocardial segments in the patients with atrial septal defect before and after surgical closure in comparison with the normal subjects (normal: 26±10.64 ms versus before closure: 21.0±33.9 versus after closure: 27±29.5, both P=0.68) and the left ventricular asynchrony index after atrial septal defect closure (normal: 14.9±8.7 versus before closure: 11.46±8.5 versus after closure: 18.12±13.6, both P=0.2). There was a significant positive relation between the tricuspid regurgitation peak gradient and the left ventricular asynchrony index (r=0.67, P=0.03) and an insignificant negative relation between the left ventricular ejection fraction and the asynchrony index before atrial septal defect closure (r=−0.53, P=0.11). No significant relation was found between the total asynchrony index and the atrial septal defect size, the degree of left-to-right shunt, and the tricuspid regurgitation peak gradient. Conclusion: There was no significant ventricular dyssynchrony in the patients with atrial septal defect before and after surgical closure. J Teh Univ Heart Ctr 3 (2009) 165-170