Echocardiogram
All echocardiograms were performed using a lab standard protocol, on
various ACUSON ultrasound machines (Siemens Medical Solutions, Malvern,
PA), using probes appropriate for patient size. Images were acquired
from parasternal long and short axis views, apical four-chamber and
two-chamber views, subcostal, and suprasternal views. Images were
transferred to dedicated workstations (Syngo Dynamics, Siemens Medical
Solutions, Malvern, PA). All measurements and analyses were performed
offline.
Echocardiogram data collected included: date of study, age at time of
study, weight (kg), height (cm), body surface area (BSA), right
ventricular (RV) size at end diastole (mm), thickness of
interventricular septum (IVS) at end diastole (mm), left ventricular
(LV) size at end diastole (mm), thickness of left ventricular posterior
wall (LVPW) at end diastole (mm), thickness of IVS at end systole (mm),
LV size at end systole (mm), thickness of LVPW at end systole (mm), LVEF
(Teicholz Formula), visual estimate of RV systolic function, presence
and severity of mitral valve stenosis, presence and severity of mitral
valve regurgitation, and presence and severity of tricuspid valve
regurgitation. To accommodate for difference in ages and thus sizes
between the +HF group and the -HF group and subsequently between the
normal and elevated CAI groups, we used the Boston Children’s Hospital
z-score system for echocardiographic parameters16,17.
The regressions used included 2D LV End-diastolic Septal Thickness vs
BSA, 2D LV End-diastolic Dimension vs BSA, 2D LV End-diastolic Free Wall
thickness vs BSA, 2D LV End-systolic Septal Thickness vs BSA, 2D LV
End-systolic Dimension vs BSA, and 2D LV End-systolic Free Wall
Thickness vs BSA.