2.2. Echocardiographic studies
The echocardiographic studies included two-dimensional, M-mode and
2D-STE. The procedures were performed by two experienced pediatric
cardiologists (TD, ÖK). The both researchers were similarly blinded to
the clinical condition and grouping of the patients. The
echocardiography device used for these procedures was Philips (model
iE33, Philips Medical Systems, Best, Netherlands) with an S5-1 MHz
transducer.
Echocardiography measurements were performed according to the
recommendations of the American Echocardiography Society standards.10 LV internal dimensions in diastole (LVIDd) and
systole (LVIDs), as well as interventricular septum thickness in
diastole (IVSd) and LV posterior wall thickness in diastole (LVPWd),
were obtained according to the same guidelines. The EF and fractional
shortening (FS) were analyzed by LV systolic function and was assessed
from the parasternal long axis on the M mode tracing view using the
Teichholz formula.11 Devereux and Reichek formula were
used to calculate LV mass (LVM, g).12
2D-STE evaluation was performed with simultaneous electrocardiography at
frame rates of 70-100 frames / sec. The peak systolic longitudinal
strain was assessed from six segments in apical long-axis (A3C),
four-chamber (A4C) and two-chamber(A2C) view. GLS was calculated by
averaging each value of regional peak longitudinal strain. Short-axis
images, obtained at the mitral valve region basal (SAXB) images,
papillary muscle region medial (SAXM), and apical levels (SAXA). These
measurements were used to compute circumferential and radial strain. At
least four consecutive cardiac cycles were recorded for each parameter
in terms of best image quality. The recorded images were transferred
from device to DVDs. A computer with QLAB software (Philips Medical
Systems) was used for analysis. For longutidinal strain, mitral annulus
lateral and septal planes and the LV apical endocardial planes were
marked by manuel. After this marking, the device automatically marks the
LV wall. The software is interactive, in that the LV endocardial and
epicardial contours was adjusted manually, and then the software
automatically tracks the contours on the subsequent frames. F
The LV algorithm was based on a 17-segment mode: AP4 (Basal septal, Mid
septal, Apical septal, Apex, Apical lateral, Mid lateral, Basal
lateral); AP3 (Basal inferolateral, Mid inferolateral, Apical lateral,
Apex, Apical anterior, Mid anteroseptal, Basal anteroseptal); and AP2
(Basal inferior, Mid inferior, Apical inferior, apex, Apical anterior,
Mid anterior, Basal anterior)(Figure1- 2)