THE KRYPTON85 INHALATION TEST FOR THE DETECTION OF LEFT-TO-RIGHT SHUNTS

Abstract

The results of inhaled Kr85 tests, carried out in 323 patients in whom the diagnosis was firmly established, were analyzed. Blood samples were drawn while the patients inhaled a Kr85 and air mixture and the results of the test were expressed as the ratio of the radioactivity in blood obtained from the right side of the heart to that obtained from a systemic artery. In the 161 patients subsequently proved to have left-to-right shunts, the results of the test ranged from 13 to 113%. In the 162 patients without cardiac shunts the results ranged from 0 to 12.2%. The Kr85 test may thus be employed with confidence for determining the presence or absence of a left-to-right shunt. In addition, when the test is successively performed in the pulmonary artery, right ventricle, and right atrium, the site of entry of the shunt into the right side of the heart may be correctly localized. The advantages of the technique in the assessment of patients with heart disease are discussed.