Temporal Sequential Pattern of Right Ventricular Free Wall Contraction in Normal Children

Area of Science:

• Pediatric Cardiology
• Echocardiography
• Cardiac Mechanics

Background:

• Right ventricular (RV) dysfunction is linked to the timing of its deformation.
• Understanding the sequence of RV free wall contraction is crucial for assessing RV function.

Purpose of the Study:

• To investigate the temporal sequence of RV free wall deformation in healthy children.
• To evaluate the timing of longitudinal and circumferential strain in different RV segments.

Main Methods:

• Prospective study involving 60 normal children.
• Speckle-tracking echocardiography and tissue Doppler imaging used to assess strain profiles and annular motion.
• Measurement of isovolumetric contraction time (ICT) and time to peak annular velocity (s').

Main Results:

• Time to peak circumferential strain was significantly earlier in the anterior RV segment compared to lateral and inferior segments.
• Longitudinal deformation occurred earlier in the RV outflow tract (RVOT) than in apical and RV inflow tract (RVIT) segments.
• Isovolumetric contraction time and time to peak s' were shorter for pulmonary annular motion than tricuspid annular motion.

Conclusions:

• Longitudinal deformation of the RVOT precedes RVIT, and anterior circumferential deformation occurs before lateral and posterior segments.
• Mechanical time heterogeneity in RV contraction is present in healthy children.
• This heterogeneity is considered important for overall RV performance.