MRI VERSUS 3D ECHOCARDIOGRAPHY IN ASSESSMENT OF LEFT VENTRICULAR FUNCTIONS IN CHILDREN WITH DILATED CARDIOMYOPATHY

Abstract

Pediatric cardiomyopathy (CM) is serious and often life-threatening condition. In children, cardiomyopathy is often a part of multisystem disorder, which requires the attention of multiple subspecialists. Dilated cardiomyopathy (DCM) is a common cause of heart failure, which is usually associated with increased left ventricular (LV) end-diastolic/end-systolic volumes (EDV, ESV) and reduced LVejection fraction (LVEF). LV volumes and LVEF provide fundamental measures of function and are Strong prognostic indicators for patients with DCM. Several techniques have been used for the determination of LV volumes and EF; among them were echocardiography and magnetic resonance imaging (MRI). MRI has evolved into a preferred technique due to the high spatial resolution and the complete volumetric data sets allowing very accurate determination of volumes and EF. Assessment of cardiac size and function is an integral part of the evaluation of the cardiac status. Therefore, an objective assessment of cardiac function is recommended. M-mode, 2D imaging, and Doppler methods can be used to assess ventricular function. Newer modalities such as 3-dimensional echocardiography, Doppler tissue imaging, and strain and strain rate calculations are promising new techniques that are currently under investigation. This cross sectional study was carried out at the Pediatric Cardiology Clinic, Children's Hospital, Ain-Shams University, to assess left ventricular functions on 20 patients diagnosed with cardiomyopathy in the period from June 2012 to October 2013. The study was also conducted on 20 healthy age and sex matched children as a control group. The aim of this study was to compare 3D echocardiography versus Cardiac MRI in assessment of left ventricular volum and functions in children with dilated cardiomyopathy. All patients were subjected to the following: • Detailed history taking and through clinical examination. • Initially routine diagnostic imaging was performed and included Motion mode (M mode), two dimentional echo (2D), Pulsed wave (PW), Continous wave (CW), as well as Coulor flow (CF) Doppler studies in the apical 4 chamber (A4C), apical 5 chamber (A5C), Parasternal long axis (PLAX) and short axis (PSAX) views. • The following parameters were assessed by m-mode of left ventricle in short axis parasternal views using a commercially available cardiac ultrasound unit, device module (VIVID E9 Vingmed Horton, Norway) and the same parameters were also assessed by 3D-speckle echocardiography and cardiac MRI (A Philips Achieva Nova (1.5 tesla) scanner super conducting system with 30mt/mint gradient with cardiac coil) as follows:- 1. Left Ventricular End Systolic Volume (LVESV (ml). 2. Left Ventricular End Diastolic Volume (LVEDV (ml). 3. Ejection Fraction (EF %) The age of studied patients ranged from one month to 14 years with a mean of age 6.6 years. Sixty five percent of studied patients (65%) were males and (35%) were females, so male to female ratio for cases of dilated cardiomyopathy was 2:1. Thirty percent of studied patients (30%) had increased heart rate for age, 55% had low systolic blood pressure for age, and 35% of them had low diastolic blood pressure for age. All studied patients were on medications and most of them were vasodilators, 100% of them were on Frusemide and Captopril therapy, 90% of them were on Digoxin and Spironolactone, 35% were on low dose acetyl salicylic acid and 20% of them were on L-carnitine. A statistically significant decrease was found in EF mean values of studied patients as assessed by 3D-echocardiography (40.25±25%) and cMRI (39.56±9.80%). There was significant increased ESV and EDV mean values indexed by BSA of all studied patients measured by 3D-ECHO, 3D-STE and CMRI. No statistically significant difference was found between 3D-echocardiography, 3D-speckle echocardiography, and cMRI in assessment of ESV (58.58±23.89ml/m2), (58.58±23.88 ml/m2), (58.65±24.11ml/m2) respectively and EDV (92.69±27.44 ml/m2), (92.84±27.29 ml/m2), (93.41±27.33 ml/m2) respectively indexed by BSA. All studied patients had global and segmental hypokinesia as assessed by 3D-STE and CMRI. No statistically significant difference was found regarding Global hypokinesia (P= 0.255), septal wall dyskinesia (P= 0.217), inferior wall hypokinesia (P= 0.072) and inferior wall akinesia (P=0.349) measured by cMRI and 3D-STE. While statistically significant increase was found in percentage of patients regarding segmental wall hypokinesia as follows:- • Apical hypokinesia 45% by cMRI versus 40% by 3D-STE (P=0.036). • Basal septal hypokinsia 85% by cMRI versus 75% by 3D-STE (P=0.045). • Mid septal hypokinesia 80% by cMRI versus 65% by 3D-STE (P=0.012). • Lateral wall hypokinesia 75% by cMRI versus 65% by 3D-STE (P=0.028).