Shunt quantification

A cardiac shunt is a pattern of blood flow in the heart that deviates from the normal circuit of the circulatory system. It may be described as right-left, left-right or bidirectional, or as systemic-to-pulmonary or pulmonary-to-systemic.

1. Shunt Quantification IN CONGENITAL AND AQUAIRED HEART DISEASES

2. Keywords

3. KEYWORDS Pvo 2 Pao 2 Sao 2 Mvo 2

4. EBF The effective blood flow (EBF) is the fraction of mixed venous return received by the lungs without contamination by LEFT TO RIGHT shunt flow

5. Normal conditions , PBF, SBF, and EBF are equal

6. Finding VO2 https://academic.oup.com/cardiovascres/article/4/1/23/267024

7. Basic rule

8. O2 sampling sites Pv  o  2  , Pa o  2  , Sa o  2  , and Mv  o  2  are oxygen saturation of pulmonary venous, pulmonary arterial, systemic arterial, and mixed venous blood, respectively

9. PBF

10. SBF

11. Mvo2 is calculated by the Flamm formula

12. Systemic arterial oxygen saturation may be substituted for pulmonary venous sampling, if at least 95%. Otherwise, in the absence of a right-to-left shunt, systemic arterial oxygen content is used. If a right-to-left shunt is present, pulmonary venous oxygen content is calculated as 98% of the oxygen capacity.

13. Clinically, the ratio of PBF to SBF (or Qp/Qs) is often used to express shunt significance. A ratio less than 1.5 indicates a small left-to-right shunt, a ratio of 1.5 to 2.0 a moderate-sized shunt, and a ratio greater than 2.0 a large left-to-right shunt. A flow ratio less than 1.0 indicates a net right-to-left shunt.

14. If oxygen consumption is NOT KNOWN

15. UTKAL DIBASA 2018