Evaluation of the ventricular mechanical dyssynchrony in patients with artrial septal detect

ABSTRACT

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 evaluated ventricular mechanical dyssynchrony in patients with artrial septal defect before and after surgical closure. Twenty patients [mean age 23 +/- 11 years] with isolated secundum or sinus venosus type artrial 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. 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 12 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. There was no significant ventricular dyssynchrony in the patients with atrial septal defect before and after surgical closure