[Detection and quantification of left-to-right intracardiac shunts by angiocardioscintigraphy].

The ratio of pulmonary/systemic output (QP/QS) was measured by angioscintigraphy in 70 patients from 1 to 22 years of age (average 10 years) admitted to the Department of pediatric cardiology for a left-to-right shunt. Fifty nine of these patients underwent cardiac cathetarisation and QP/QS determination by oxymetry. The correlation between the values of QP/QS calculated by the two techniques was R = 0,83 (p less than 0,001: n = 59); in 28 cases of atrial septal defect R = 0,85; in 20 cases of ventricular septal defect, R = 0,75; in 11 cases of other left-to-right shunts, R = 0,79. No significant shunt was detected in 16 patients by oxymetry and the QP/QS ratio on angioscintigraphy was less than or equal to 1,2 except in 3 cases. In 7 cases of isolated pulmonary stenosis and 4 cases of operated septal defects no shunt could be detected by isotopic investigation. We conclude that angioscintigraphy is a reliable non-invasive method of detection and assessment of left-to-right shunts. In some cases it may avoid the necessity of cardiac catheterisation. The advantages, limitations and applications of this method are discussed.