Assessment of atrial septal defect area changes during cardiac cycle by live three-dimensional echocardiography.

OBJECTIVES To investigate the accuracy of measurement of the atrial septal defect (ASD)area and dynamic change by live three-dimensional echocardiography (L3DE). METHODS L3DE was performed in patients with ASD using a three-dimensional workstation to obtain the en face view of the ASD and measure its area at the peak of P-wave, the peak of R-wave, the initial and the destination point of T-wave, and the period of P-T. Parameters derived from L3DE were compared with intraoperative measurements. RESULTS The ASD area changed significantly during cardiac cycles (mean change 46.1%, p < 0.0001; range 15.2-72.5%), with the maximal area at endsystole and the minimal area at enddiastole. There was excellent correlation between L3DE and intraoperative measurements for the area of ASD at the peak of P-wave (r = 0.92). There were good correlations between the two methods during the other phases of cardiac cycle (r = 0.81-0.86). CONCLUSIONS L3DE provides accurate and feasible measurements of the ASD area. Investigation of the dynamic changes during the cardiac cycle may lead to an improved understanding of the hemodynamics of ASD.