Krypton-85 in the Detection of Intracardiac Left-to-Right Shunts

ANUMBER of methods have been developed for detecting left-to-right shunts during cardiac catheterization of which the most frequently employed is determining the difference in oxygen saturations. This method has limited application in the presence of small shunts, however, since the minimal changes are often within the error of this method.' Therefore, other more sensitive technics have been employed including the use of radioactive gases, dye dilutions,2 3 hydrogen ion-platinum electrode systems,4' and cineangiocardiography. Braunwald's group initially employed nitrous oxide for the detection of intracardiac shunts6 and then developed a method for the detection of left-to-right shunts using krypton-85. 8 It was found that this gas could be the basis for a sensitive screening test and could also localize such shunts. It is the purpose of the present study to report the results in 175 patients in whom krypton-85 was employed for the detection of intracardiac shunts.