Of the various techniques that are available to assess the presence and magnitude of intracardiac shunting, oximetry and indicator dilution are used most frequently. This study was performed to compare these methods in adult patients with pure left to‐right intracardiac shunting. In 27 patients [12 men, 15 women, aged 32 ± 12 (mean ±SD) years], shunt magnitude was assessed in close temporal proximity by both techniques. The oximetric percentage left‐to‐right shunt averaged 55 ± 16%, whereas the indocyanine green dye percentage shunt was significantly less (36 ± 14%, p < 0.001). The oximetric percentage shunt exceeded the indocyanine green dye percentage shunt in 26 and did so by >20% in 23 patients. Thus, there is a substantial difference in shunt magnitude between the oximetric and the indicator dilution techniques. In infants, indicator dilution yields results that are larger than those obtained with the oximetric method. Conversely, in adults, the indicator dilution technique gives results that are consistently smaller than those obtained with oximetry. As a result, the decision regarding therapy of an intracardiac shunt should be made with this in mind.
- indicator dilution
- intracardiac shunt
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine