Clinical value of Doppler echocardiography in the determination of shunt size in atrial septal defect of adult patients

The purpose of this study was to assess the clinical utility of pulsed Doppler echocardiography in the determination of shunt flow magnitude in adults with an atrial septal defect. Therefore, in 24 unselected, consecutive adult patients with an ostium-secundum type atrial septal defect, and in 16 patients without heart disease, Doppler echocardiography was performed to measure blood flow in the right and left ventricular outflow tract. In eight patients with an atrial septal defect, pulmonary flow measurement was impossible because of pulmonary insufficiency or poor visualization of the pulmonary annulus. The ratio between the pulmonary (Qp) and systemic blood flow (Qs) was between 0.83 and 1.13 in the control group and between 1.31 and 4.46 in patients with an atrial septal defect. In the control group the correlation between Qs and Qp was r = 0.96 (SEE = 0.417 l/min, y = 1.05x - 0.21). The correlation between Qp/Qs, determined by oximetry and pulsed Doppler echocardiography in patients with an atrial septal defect, was significant (r = 0.82, SEE = 0.54). Systematic differences between invasive and non-invasive shunt calculations did not occur. Thus, pulsed Doppler echocardiography is clinically useful in the determination of shunt flow magnitude in about two thirds of adult patients with an atrial septal defect and provides precise information for the decision for conservative or operative treatment.