Detection of Cardiac Right-to-Left Shunts by External Counting of ¹³³Xenon

Abstract

¹³³Xenon appearance times were recorded externally over the abdominal part of aorta and the precordium in 43 patients, 15 of whom had a cardiac right-to-left shunt. Significantly shorter appearance times were found in the shunt group both after tracer injection in a peripheral arm vein and in the superior caval vein. False negative and false positive results due to individual differences in the distribution volume and flow rate of the indicator are discussed. The method provides a qualitative measure of cardiac right-to-left shunts, and is suggested as a preliminary procedure before heart catheterization and for the evaluation of residual shunts after reconstructive cardiac surgery. The external recordings may also prove valuable for localization of shunts during heart catheterization.

Key Words:

• Cardiac right-to-left shunt
• central/peripheral tracer injection
• external detection
• height
• ¹³³Xenon