Synchronicity of systolic deformation in healthy pediatric and young adult subjects: a two-dimensional strain echocardiography study.

Two-dimensional speckle tracking echocardiography (2DSTE) offers valuable information in the echocardiographic assessment of ventricular myocardial function. It enables the quantification and timing of systolic ventricular myocardial deformation. In addition, 2DSTE can be used to identify mechanical dyssynchrony, which is an important parameter in predicting the response to cardiac resynchronization therapy for heart failure. Detailed knowledge of normal timing of systolic deformation and its degree of synchronicity in children is lacking. We aimed to establish the normal timing of left ventricular myocardial systolic deformation using 2DSTE in a large cohort of healthy children and young adults. Transthoracic echocardiograms were acquired in 195 healthy subjects (139 children and 56 young adult <40 yr of age) and were retrospectively analyzed. Time to peak systolic longitudinal, circumferential, and radial strain was determined by means of speckle tracking. Strong, statistically significant relations between age as well as various anthropometric variables (e.g., heart rate) and timing of systolic deformation (P < 0.0001) were present. The extent of dyssynchronous deformation increased with age. This is the first report that establishes reference values per cardiac segment for time to peak systolic myocardial strain values in all three directions assessed with 2DSTE in a large pediatric and young adult cohort. We emphasize the need for using age-specific reference values as well as heart rate correction for the adequate interpretation of 2DSTE measurements.

Causes of Death in Adults with Mitochondrial Disease.

INTRODUCTION: Mitochondrial diseases are a clinically, biochemically and genetically heterogeneous group of disorders with a variable age of onset and rate of disease progression. It might therefore be expected that this variation be reflected in the age and cause of death. However, to date, little has been reported regarding the 'end-of-life' period and causes of death in mitochondrial disease patients. For some specific syndromes, the associated clinical problems might predict the cause of death, but for many patients, it remains difficult to provide an accurate prognosis. AIMS: To describe a retrospective cohort of adult mitochondrial disease patients who had attended the NHS Highly Specialised Services for Rare Mitochondrial Diseases in Newcastle upon Tyne (UK), evaluate life expectancy and causes of death and assess the consequences for daily patient care. METHODS: All deceased adult patients cared for at this centre over a period of 10 years were included in the study. Patient history, data on laboratory findings, biochemical investigations and genetic studies were analysed retrospectively. RESULTS: A total of 30 adult mitochondrial patients died within the time period of the study. The main mitochondrial disease-related causes of death in this patient cohort were respiratory failure, cardiac failure and acute cerebral incidents such as seizures and strokes. In almost half of the patients, the cause of death remained unknown. Based on our study, we present recommendations regarding the care of patients with mitochondrial disease.

Reference values for myocardial two-dimensional strain echocardiography in a healthy pediatric and young adult cohort.

BACKGROUND: The accurate evaluation of intrinsic myocardial contractility in children with or without congenital heart disease (CHD) has turned out to be a challenge. Two-dimensional strain echocardiographic (2DSTE) imaging or two-dimensional speckle-tracking echocardiographic imaging appears to hold significant promise as a tool to improve the assessment of ventricular myocardial function. The aim of this study was to estimate left ventricular myocardial systolic function using 2DSTE imaging in a large cohort consisting of healthy children and young adults to establish reference strain values. METHODS: Transthoracic echocardiograms were acquired in 195 healthy subjects (139 children, 56 young adults) and were retrospectively analyzed. Longitudinal, circumferential, and radial peak systolic strain values were determined by means of speckle tracking. Nonlinear regression analysis was performed to assess the effect of aging on these 2DSTE parameters. RESULTS: There was a strong, statistically significant second-order polynomial relation (P < .001) between global peak systolic strain parameters and age. Global peak systolic strain values were lowest in the youngest and oldest age groups. CONCLUSION: This is the first report to establish age-dependent reference values per cardiac segment for myocardial strain in all three directions assessed using 2DSTE imaging in a large pediatric and young adult cohort. There is a need to use age-specific reference values for the adequate interpretation of 2DSTE measurements.

Early detection of myocardial dysfunction in children with mitochondrial disease: An ultrasound and two-dimensional strain echocardiography study.

BACKGROUND: Myocardial dysfunction in children diagnosed with mitochondrial disease is an ominous sign and has been associated with substantial increased mortality rates. Early detection of cardiac involvement would therefore be desirable. Two dimensional strain echocardiography (2DSTE) has proven to be more sensitive than conventional echocardiography for the detection of early myocardial dysfunction in various (cardiac) conditions. AIMS: To determine left ventricular systolic function in children with mitochondrial disorders by means of physical examination, electrocardiography (ECG), conventional echocardiography and 2DSTE. METHODS: A total of 27 children with established mitochondrial disease and 54 age-matched control subjects underwent cardiac evaluation. Longitudinal, circumferential and radial peak systolic strain (S) values were determined as well as peak systolic strain rate (Sr) and the time to peak global systolic strain (T2P). One Way analysis of Variance was performed to assess the influence of the presence of mitochondrial disease on conventional echocardiographic and 2DSTE outcomes. RESULTS: Conventional echocardiographic findings did not indicate systolic left ventricular dysfunction. Global peak S, Sr and T2P measurements in all three directions were significantly lower in children with mitochondrial disease (P<0.001) when compared to controls. CONCLUSION: 2DSTE detects alterations in myocardial systolic function in children diagnosed with mitochondrial disease, whose conventional echocardiographic findings did not indicate ventricular systolic dysfunction.