Two-Dimensional Strain is more Precise than Conventional Measures of Left Ventricular Systolic Function in Pediatric Patients.

Ejection fraction (EF) and fractional shortening (FS) are standard methods of quantifying left ventricular (LV) systolic function. 2D global longitudinal strain (2D GLS) is a well-established, but underutilized method for LV function quantification. The aim of this study was to assess precision of GLS compared to EF & FS in pediatrics. Echocardiograms were prospectively analyzed by 2 blinded observers. FS, EF, and GLS were calculated following standard methods. Bland-Altman was applied to assess agreement. Intraclass correlation coefficient (ICC) was used to measure reliability. Coefficient of variation was used to demonstrate relative variability between methods. 103 pediatric echos were evaluated for inter-observer reproducibility, and 15 patients for intra-observer reproducibility. GLS had higher inter-observer agreement and reliability (bias 7%, 95% LOA - 3.4 to + 3.5, ICC 0.86 CI 0.80-0.90) compared to EF (bias 27%, 95% LOA - 18.9 to + 19.5; ICC 0.25 CI 0.07-0.43) and FS (bias 12%, 95% LOA - 11.9 to + 12.2; ICC 0.53 CI 0.38-0.66). GLS also had higher intra-observer agreement (bias 4%, 95% LOA - 3.6 to + 3.7; ICC 0.87 CI 0.66-0.96) compared to EF (bias 11%, 95% LOA - 14.9 to + 15.1; ICC 0.26 CI - 0.28-0.67) and FS (bias 12%, 95% LOA - 12.2 to + 12.5; ICC 0.38 CI - 0.15-0.74). GLS is a more precise method for quantifying LV function in pediatrics, with lower variability compared to EF and FS. GLS provides a more reliable evaluation of LV systolic function and should be utilized more widely in pediatrics.

Doppler echocardiography inaccurately estimates right ventricular pressure in children with elevated right heart pressure.

BACKGROUND: Doppler echocardiography (DE) is widely used as a surrogate for right heart catheterization (RHC), the gold standard, to assess and monitor elevated right heart pressure in children. However, its accuracy has not been prospectively validated in children. The objectives of this study were to evaluate the accuracy of DE in predicting simultaneously measured right ventricular (RV) pressure by RHC in pediatric patients and to determine if the degree of RV hypertension affects the accuracy of DE in assessing right heart pressure. METHODS: Eighty children (age range, 0-17.9 years; median age, 5.5 years) with two-ventricle physiology and a wide range of right heart pressures underwent simultaneous DE and RHC. The pressure gradient between the right ventricle and the right atrium was directly measured by RHC and simultaneously estimated by DE using tricuspid regurgitation. Patients were then grouped on the basis of RHC-measured RV systolic pressure (RVSP): group 1 (n = 43), with RVSP < 1/2 systemic systolic blood pressure (SBP); group 2 (n = 37), with RVSP ≥ 1/2 SBP; group 3 (n = 56), with RVSP < 2/3 SBP; and group 4 (n = 24), with RVSP ≥ 2/3 SBP. Correlation and Bland-Altman analyses were performed on all groups. Accuracy was predefined as 95% limits of agreement within ±10 mm Hg. RESULTS: Despite a reasonable correlation between DE and RHC in all groups, there was poor agreement between techniques as RVSP/SBP increased. DE was inaccurate in one of 43 patients in group 1 (2%) versus nine of 37 in group 2 (24%) and was inaccurate in one of 56 patients in group 3 (2%) versus eight of 24 in group 4 (33%). Overestimation and underestimation occurred equally in all groups. CONCLUSION: DE inaccurately estimates RV pressure in children with elevated right heart pressure. It should not be relied on as the sole method of assessing right heart hemodynamics in children with RV hypertension.