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. 2022 Jan-Feb;15(1):20-26.
doi: 10.4103/apc.apc_139_21. Epub 2022 Jun 14.

Correlation of transthoracic echocardiography-derived pulmonary to systemic flow ratio with hemodynamically estimated left to right shunt in atrial septal defects

Erin Faherty  1 , Hari Rajagopal  2 , Simon Lee  3 , Barry Love  4 , Shubhika Srivastava  5 , Ira A Parness  2 , Santosh C Uppu  6
Affiliations

Correlation of transthoracic echocardiography-derived pulmonary to systemic flow ratio with hemodynamically estimated left to right shunt in atrial septal defects

Erin Faherty et al. Ann Pediatr Cardiol. 2022 Jan-Feb.

Abstract

Background: Transthoracic echocardiographic (TTE) estimation of the pulmonary to systemic flow ratio (Qp/Qs) is routinely used in clinical practice and is included in the American Society of Echocardiography Guidelines. We sought to assess its real-world applicability with a particular focus on hemodynamically significant shunt lesions.

Methods: Retrospective single institutional review of TTE's in patients with secundum atrial septal defect prior to cardiac catheterization (cath) from 2012 to 2018 was performed (n = 109), those with technically limited images for Qp/Qs calculation (n = 11) and those with time interval between TTE and cath >60 days were excluded (n = 14). Qp/Qs was calculated from stored clips by previously described methods and correlated with those obtained by oximetry. Patients were subdivided into two age groups <21 (Group 1) and ≥22 years (Group 2). TTE and cath methods for Qp/Qs estimation were compared using paired t-test, Pearson's correlation coefficient, and Bland-Altman plots.

Results: Eighty-four subjects met inclusion criteria (age range 3-78 years). Group 1 n = 35; median age 10 years; Group 2 n = 49; median age 49 years. Transthoracic echocardiogram was performed 19.5 ± 15 days prior to cath. Mean Qp/Qs derived by cath and TTE were 2.09 ± 0.9 versus 2.54 ± 1.2 (P < 0.0001). Overall correlation was poor between the methods (r 2 = 0.32, P < 0.0001) and continued to be poor for Groups 1 and 2 (r 2= 0.24, P = 0.003 and r 2= 0.40, P < 0.0001 respectively). Bland-Altman plots demonstrated poor agreement between the predetermined limits of agreement (-0.5-1.5).

Conclusion: Transthoracic echocardiography estimated Qp/Qs, although routinely utilized in clinical practice, has poor correlation and agreement with oximetry-derived Qp/Qs. The test performs poorly in all age groups in detecting a hemodynamically significant shunt and tends to overestimate the degree of left to right shunt.

Keywords: Atrial septal defect; left to right shunt; oximetry; transthoracic echocardiography.

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Conflict of interest statement

There are no conflicts of interest.

Figures

Figure 1
Figure 1
Illustrations demonstrating the measurement of flow velocity (red dotted arrow) (a) and diameter (b) of the left ventricular outflow tract (red solid double headed arrow), and the measurement of the flow velocity (red dotted arrow) (c) and diameter (d) of the right ventricular outflow tract (red solid double headed arrow).
Figure 2
Figure 2
Estimated Qp/Qs by echo and Qp/Qs estimated by cath, with line of equality. Qp/Qs: Pulmonary to systemic flow ratio
Figure 3
Figure 3
Estimated Qp/Qs by echo and Qp/Qs estimated by cath for subjects <21 yo (a) and for subjects ≥22 yo (b). Qp/Qs: Pulmonary to systemic flow ratio
Figure 4
Figure 4
Difference of echo and cath estimated Qp/Qs against mean Qp/Qs. Qp/Qs: Pulmonary to systemic flow ratio
Figure 5
Figure 5
Difference between echo and cath estimated Qp/Qs against mean Qp/Qs for cath Qp/Qs <1.5 (a) difference between echo and cath estimated Qp/Qs against mean Qp/Qs for cath Qp/Qs >1.5 (b) difference between echo and cath estimated Qp/Qs against mean Qp/Qs for cath Qp/Qs >2.0 (c). Qp/Qs: Pulmonary to systemic flow ratio
See this image and copyright information in PMC

References

    1. Quiñones MA, Otto CM, Stoddard M, Waggoner A, Zoghbi WA. Doppler Quantification Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography. Recommendations for quantification of Doppler echocardiography: A report from the Doppler quantification task force of the nomenclature and standards committee of the American Society of Echocardiography. J Am Soc Echocardiogr. 2002;15:167–84. - PubMed
    1. Lang RM, Badano LP, Mor-Avi V, Afilalo J, Armstrong A, Ernande L, et al. Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28:1–39.e14. - PubMed
    1. Sanders SP, Yeager S, Williams RG. Measurement of systemic and pulmonary blood flow and QP/QS ratio using Doppler and two-dimensional echocardiography. Am J Cardiol. 1983;51:952–6. - PubMed
    1. Kitabatake A, Inoue M, Asao M, Ito H, Masuyama T, Tanouchi J, et al. Noninvasive evaluation of the ratio of pulmonary to systemic flow in atrial septal defect by duplex Doppler echocardiography. Circulation. 1984;69:73–9. - PubMed
    1. Vargas Barron J, Sahn DJ, Valdes-Cruz LM, Lima CO, Goldberg SJ, Grenadier E, et al. Clinical utility of two-dimensional doppler echocardiographic techniques for estimating pulmonary to systemic blood flow ratios in children with left to right shunting atrial septal defect, ventricular septal defect or patent ductus arteriosus. J Am Coll Cardiol. 1984;3:169–78. - PubMed