Pulmonary artery wedge catheter position as a site for injection of indicator substance.

THE use of indicator-dilution curves during cardiac catheterization has greatly clarified the hemodynamics of various congenital cardiovascular malformations.1 2 As presently used, the combination of indicatordilution curves and oximetry is usually sufficient to establish a definitive diagnosis. In some subjects with small left-to-right intracardiac shunts, however, the usual diagnostic methods are inadequate. In attempts to prove the existence of small shunits additional diagnostic procedures may be required such as the placement of 2 catheters in the right side of the heart3 or catheterization of the left side of the heart.4 The present study reports the injection of indicator substance with the catheter in the pulmonary wedge position as an additional diagnostic aid.