Measurement of Individual Ventricular Outputs in the Fetal Lamb by a Dye Dilution Technique

Individual ventricular outputs were measured in 25 fetal lambs using an indicator dilution method. Small volumes of indocyanine green were injected through catheters placed in the individual ventricles; sampling for the left ventricle was from a catheter placed in the brachiocephalic artery through the carotid artery and for the right ventricle sampling was from a catheter placed in the ductus arteriosus via a femoral artery and the aorta. Mean left ventricular output obtained by this method was 181.7 ml/kg per min and mean right ventricular output was 179.7 ml/kg per min. We suggest that the rapidity of preparation and relative lack of trauma involved in this method may account for values that are higher than those reported previously.