Assessment of early diastolic intraventricular pressure gradient in the left ventricle among patients with repaired tetralogy of Fallot.

Assessment of left ventricular (LV) dysfunction is vital in patients with repaired tetralogy of Fallot (rTOF). The early diastolic intraventricular pressure gradient (IVPG) in the LV plays an important role in diastolic function. IVPG is calculated as the intraventricular pressure difference divided by the LV length, which allows to account for differences in LV size and therefore calculate IVPG in children. We aimed to investigate the mechanisms of LV diastolic dysfunction by measuring mid-to-apical IVPG as an indicator of the active suction force sucking blood from the left atrium into the LV. We included 38 rTOF patients and 101 healthy controls. The study population was stratified based on age group into children (4-9 years), adolescents (10-15 years), and adults (16-40 years). IVPGs were calculated based on mitral inflow measurements obtained using color M-mode Doppler echocardiography. Although total IVPGs did not differ between rTOF patients and controls, mid-to-apical IVPGs in adolescents and adults were smaller among rTOF patients than among controls (0.15 ± 0.05 vs. 0.21 ± 0.06 mmHg/cm, p < 0.05; 0.09 ± 0.07 vs. 0.17 ± 0.05 mmHg/cm, p < 0.001; respectively). Additionally, only mid-to-apical IVPG correlated linearly with peak circumferential strain (ρ = 0.217, p = 0.011), longitudinal strain (ρ = -0.231, p = 0.006), torsion (ρ = -0.200, p = 0.018), and untwisting rate in early diastole (ρ = -0.233, p = 0.006). In rTOF, the mechanisms underlying diastolic dysfunction involve reduced active suction force, which correlates with reduced LV deformation in all directions.

Assessment of the developmental change in the left atrial volume using real time three-dimensional echocardiography.

AIMS: Real time 3D echocardiography (RT3DE) has been applied for the assessment of left atrial (LA) function in patients with adult heart disease; however, LA function is not well known in children. We aimed at determining the normal range of LA volume (LAV) using RT3DE and the feasibility and reproducibility of this method in healthy subjects and at elucidating the developmental changes in the LAV with aging. METHODS AND RESULTS: In this study, 359 healthy people (mean age, 23.9 ± 21.3; range, 0.1-76.4 years) were enrolled. We performed transthoracic RT3DE and measured the maximum and minimum LAV. Simultaneously, we measured the LAV using the 2D biplane Simpson's method. Inter-observer and intra-observer variability and the agreement of LAV measurements between RT3DE and 2DE were assessed in a subset of subjects. The RT3DE feasibility for LAV measurement was 93%. Both maximum and minimum LAVs exponentially increased with age and linearly increased with increasing of body surface area (BSA). The LA distensibility, which demonstrates LA reservoir function, decreased with age and BSA. The LAVs measured by RT3DE were significantly smaller than those measured by the 2D biplane Simpson's method. The 3D volumetric method had favorable intra-observer and inter-observer agreement. CONCLUSION: The reference values of LAV from early infancy to adulthood were obtained using RT3DE, which could be useful for future studies in children with congenital heart disease. RT3DE is a reproducible method and a feasible tool for evaluating the LAV in children. LA reservoir function is likely to decrease with age and increasing of body size.