Intracardiac right-to-left shunts demonstrated by two-dimensional echocardiography after peripheral vein injection

The usefulness of performing real time cross-sectional echo contrast studies, using peripheral venous injections of dextrose 5 per cent in water, for the detection and localisation of atrial and ventricular right-to-left shunts was evaluated in 70 adult patients. Based on their catheterisation data, 20 patients had a shunt at atrial level and 14 patients a ventricular septal defect. Thirty-six patients without a shunt by oximetry served as controls. Echo contrast could not be detected in the left-sided cardiac cavities in any of the control patients. In 11 of the 15 patients with an uncomplicated atrial septal defect of the secundum type, echo contrast appeared at the left side of the heart and this small right-to-left shunting occurred in systole. Left-sided echo contrast was demonstrated in the 5 patients in whom a bidirectional atrial shunt was found by oximetry. Of the 14 patients with a ventricular septal defect, 7 had a ratio of right-to-left ventricular pressure exceeding 50 per cent and early diastolic right-to-left shunting of echo contrast was observed in all. This was not seen in any of the patients with an uncomplicated ventricular septal defect. Diagnostic real time ultrasonic cross-sectional contrast studies can thus be performed in adults using peripheral venous injections of dextrose 5 per cent in water. The presence and timing of intracardiac right-to-left shunts, even when small, are greatly facilitated.