Variability of echocardiographic parameters in systemic right ventricle
Authors: Prokselj K , Pavsic N , Kacar P , Ivanac Vranesic I , Brida M 
Published: February 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.
Introduction
In transposition of the great arteries after atrial switch repair (TGA-AS), systemic circulation is supported by morphological RV. Initial remodeling of this systemic RV (sRV) is inevitably followed by ventricular enlargement and dysfunction. The evaluation of sRV size and function is therefore essential in the follow-up of TGA-AS patients. Although magnetic resonance imaging is considered the gold standard for sRV evaluation, transthoracic echocardiography (TTE) remains the most commonly used in everyday clinical practice. Comprehensive evaluation of sRV size and function is challenging even for experienced TTE operators. Furthermore, due to the lack of specific and standardized recommendations, TTE examinations also vary between operators and centres.
Purpose
We sought to determine interobserver variability in echocardiographic parameters for assessment of sRV size and function in patients with TGA-AS.
Methods
We retrospectively analysed echocardiographic recordings of all patients with TGA-AS from two national centres for adults with congenital heart disease (Centre 1: University Medical Centre Ljubljana, Slovenia and Centre 2: University Hospital Centre Zagreb, Croatia). Three congenital cardiologists (1 from Centre 1 and 2 from Centre 2), skilled in echocardiography and blinded for patients’ clinical data, reviewed offline TTE images on EchoPac (GE Vingmed Ultrasound).
According to the recommendations, we obtained the following parameters of RV size and function: a) quantitative parameters: RV end diastolic dimension (RVEDD), RV hypertrophy (RVH), RV ejection fraction estimated in percentage (RV EF %), tricuspid annular plane systolic excursion (TAPSE), tissue Doppler tricuspid annulus S wave velocity (TDI S"), fractional area change (FAC), RV global longitudinal strain (RV GLS) and b) qualitative parameters: RV enlargement, RVEF by eyeballing and tricuspid regurgitation (TR). Qualitative parameters were classified into four categories: no/normal, mild, moderate, severe.
Intraclass correlation coefficients (ICC) were calculated to evaluate interobserver variability, and values were classified into five reliability categories: &lt;0.50 (poor), between 0.50 and 0.75 (moderate), between 0.75 and 0.90 (good), and above 0.90 (excellent interobserver agreement).
Results
In total, we identified 35 patients with TGA-AS (Centre 1: 15 patients, Centre 2: 20 patients). One patient was excluded from the analysis due to insufficient imaging data. In the remaining 34 patients, we showed excellent interobserver agreement in 5 parameters (TAPSE, RVEF eyeballing and RVEF %, RV GLS, TR) and good interobserver agreement in 4 parameters (RVEDD, RV enlargement, TDI S’, FAC). Only RVH showed moderate agreement (Table).

Conclusion
Echocardiographic parameters in sRV show good to excellent agreement between skilled investigators. According to our results, echocardiography performed by experienced operators is a reliable imaging method in sRV. Abstract Table