Assessment of cardiac dimensions in children diagnosed with hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is an inherited autosomal dominant heart disease, characterized by increased left ventricular wall thickness and abnormal loading conditions. Imaging modalities are the first choice for diagnosis and risk stratification. Although heart dimensions have been characterized widely in HCM adults from cardiac imaging, there is limited information about children affected by HCM. The aim of this study is to evaluate left ventricular function and left heart dimensions in a small population of children diagnosed with HCM. METHODS: A total of 16 (seven male, nine female) pediatric patients with an average age of 14.0 ± 2.5 years diagnosed with HCM at Great Ormond Street Hospital for Children were included in this study. Cardiac magnetic resonance (CMR) images were used to measure left and right ventricular dimensions, and septal and left ventricular free wall thicknesses in Simpleware ScanIP. The gender groups were compared using student t-test or non-parametric Mann-Whitney U-test depending on the sample distribution. RESULTS: Differences in heart rate, left ventricular end-diastolic volume and end-diastolic volume index, left ventricular stroke volume and stroke volume index, left ventricular end-systolic long axis length, left ventricular end-systolic long axis length index, left ventricular end-diastolic mid-cavity diameter, left ventricular end-diastolic free wall thickness, left ventricular end-diastolic free wall thickness index, right ventricular end-diastolic long axis length were statistically significant in males and females. CONCLUSION: Left ventricular wall and intraventricular septal thickness increase affecting left ventricle cavity dimensions and there may be differences in anatomical and physiological parameters in males and females affected by HCM.

Patient-Specific Modelling and Parameter Optimisation to Simulate Dilated Cardiomyopathy in Children.

PURPOSE: Lumped parameter modelling has been widely used to simulate cardiac function and physiological scenarios in cardiovascular research. Whereas several patient-specific lumped parameter models have been reported for adults, there is a limited number of studies aiming to simulate cardiac function in children. The aim of this study is to simulate patient-specific cardiovascular dynamics in children diagnosed with dilated cardiomyopathy, using a lumped parameter model. METHODS: Patient data including age, gender, heart rate, left and right ventricular end-systolic and end-diastolic volumes, cardiac output, systolic and diastolic aortic pressures were collected from 3 patients at Great Ormond Street Hospital for Children, London, UK. Ventricular geometrical data were additionally retrieved from cardiovascular magnetic resonance images. 23 parameters in the lumped parameter model were optimised to simulate systolic and diastolic pressures, end-systolic and end-diastolic volumes, cardiac output and left and right ventricular diameters in the patients using a direct search optimisation method. RESULTS: Difference between the haemodynamic parameters in the optimised cardiovascular system models and clinical data was less than 10%. CONCLUSION: The simulation results show the potential of patient-specific lumped parameter modelling to simulate clinical cases. Modelling patient specific cardiac function and blood flow in the paediatric patients would allow us to evaluate a variety of physiological scenarios and treatment options.