Right Ventricular Systolic Function Parameters in Hypoplastic Left Heart Syndrome

Area of Science:

• Pediatric Cardiology
• Echocardiography
• Congenital Heart Disease

Background:

• Assessing right ventricular (RV) systolic function in hypoplastic left heart syndrome (HLHS) is clinically important but challenging due to the RV's unique anatomy.
• Novel echocardiographic parameters are needed to accurately differentiate between preserved and reduced RV function in HLHS patients.
• Establishing normal cut-off values for these novel measures is essential for clinical application and research.

Purpose of the Study:

• To compare novel RV systolic function measures between normal controls, HLHS patients with preserved function, and HLHS patients with reduced function.
• To establish cut-off values for RV global longitudinal strain (RVGLS) and tissue motion annular displacement of the tricuspid valve (TMAD-TV) that differentiate preserved from reduced RV function in HLHS.

Main Methods:

• Retrospective echocardiographic analysis of 41 HLHS patients (20 reduced function, 21 preserved function) and 27 age-matched normal controls.
• Functional assessments included fractional area change (FAC), TMAD-TV, TMAD-pulmonary valve (TMAD-PV), myocardial performance index (MPI), and tricuspid S' velocity.
• FAC < 35% was used as the reference standard to define reduced RV function.

Main Results:

• In HLHS with preserved function, tissue Doppler S', MPI, and TMAD-TV were abnormal compared to normal controls (p < 0.05).
• All measures were significantly worse in HLHS with reduced function compared to both normal controls and HLHS with preserved function (p < 0.05).
• Established cut-off values for preserved vs. reduced RV function in HLHS were: TMAD-TV of 14.5% and RVGLS of 16%.

Conclusions:

• Novel echocardiographic measures, including TMAD-TV and RVGLS, can effectively distinguish between preserved and reduced RV systolic function in HLHS.
• Established cut-off values for TMAD-TV and RVGLS provide valuable reference points for future research and clinical assessment of RV function in HLHS.
• Even in HLHS with preserved function, several novel measures indicated worse function compared to normal controls, highlighting the sensitivity of these parameters.