Myocardium In Children Research Articles

Electrical Instability of the Myocardium in Children and Adolescents

Currently, there is no doubt that the problem of electrical instability of the myocardium in pediatric cardiology is relevant. The determination of various indicators of electrical instability of the myocardium, which are predictors of life-threatening rhythm disorders and sudden cardiac death, presents an underdeveloped task not only for functional diagnostics specialists, but also for pediatricians, neonatologists, pediatric cardiologists and doctors of other specialties. Non-invasive research methods such as electrocardiography (ECG), Holter ECG monitoring (HM ECG), available in almost all pediatric treatment and prevention institutions, are quite informative in terms of detecting electrophysiological heterogeneity of the myocardium as a predictor of sudden cardiac death, which is especially important in children at risk, as well as young athletes. Thus, the determination of indicators of electrical instability of the myocardium is of great interest, it is a promising direction in modern clinical practice, allowing to predict the risk of developing fatal arrhythmias in children and adolescents.

Morphology of the myocardium of the interventricular septum in children with hypertrophic cardiomyopathy

To carry out a comparative analysis of the morphology of the interventricular septum (IVS) myocardium in children with hypertrophic cardiomyopathy (HCM) and without cardiovascular pathology. A study of myocardial biopsies of the IVS in children with HCM (n=18, 1.2-17 years) and children without cardiovascular pathology (n=11, 1-16 years) was carried out. The volume of interstitial tissue in the IVS myocardium was determined, a morphometric study of the size of cardiomyocytes (CMCs), the myofibrillogenesis level and the ploidy of CMCs was carried out, the ultrastructure of the CMCs was studied, and the localization of the gap junction protein, connexin43 (Cx43), was revealed by immunohistochemistry. The proportion of interstitial tissue in the myocardium of children with HCM was 9-10% and did not differ from its proportion in the myocardium of children in the control group. The diameter of the CMCs of the IVS in children with HCM reached the limit of ontogenetic growth and exceeded the parameters of the control group (average 18.9±5.7 µm vs 9.3±4.4 µm). CMCs ploidy in children with HCM was 2 times higher than CMCs ploidy in control patients (5.3c vs 2.7c). In the myocardium of children with HCM, the assembly of myofibrils most actively occurred in small CMCs. At the ultrastructural level, signs of immaturity of the contractile apparatus and intercalated discs of the CMC in HCM were demonstrated. In the myocardium of children with HCM, Cx43-containing gap junctions were more often located on the lateral surfaces of the CMC than in the myocardium of the control group. In children with HCM, a morphological picture of an increase in the size of the CMCs and their ploidy during accelerated ontogenetic development was demonstrated in combination with ultrastructural signs of immaturity of the contractile apparatus and intercalated discs and the lack of growth of interstitial tissue of the IVS myocardium compared with patients in the control group.

Parvovirus B19-Associated Myocarditis: A Literature Review of Pediatric Cases.

Parvovirus B19 (B19V) infection may lead to myocarditis, a life-threatening condition in pediatric patients. In this review, we aim to present published pediatric cases of B19V-associated myocarditis in order to understand the deep complex connections and draw useful conclusions. We performed a comprehensive search of MEDLINE, Science Direct, and Google Scholar electronic databases. A total of 32 cases were included in our study. The most common presenting symptom was tachycardia in 22/32 patients (68.7%), followed by tachypnoea (21/32, 65.6%), fever, and rash (12/32, 37.5% for both of them). Cardiac arrest, loss of consciousness, and systemic infection were associated with the worst prognosis, with statistically significant differences (p-value 0.001, 0.02, 0.001. respectively). A percentage as high as 90.4% of patients with left ventricular (LV) dysfunction and reduced ejection fraction (EF) were discharged. Twelve patients required ventilatory support, five required extracorporeal membrane oxygenation (ECMO), and three underwent heart surgery. Treatment with immunosuppressive agents and immunoglobulin was found to be beneficial for patients (p-value 0.006 and 0.004, respectively). In conclusion, B19V myocarditis has high mortality rates in children. There is no specific antiviral treatment for B19V infection and therapeutic strategies for myocarditis aim to delay the worsening of heart failure and to preserve the LV function. Inotropic drugs, diuresis, ventilatory support, Intravenous immunoglobulin (IVIG), and immunosuppressive therapy seem to help the recovery of the myocardium in children with LV dilation, dysfunction, and reduced EF. Children with cardiac arrest, arrhythmias, and loss of consciousness have the worst prognosis.

Accelerated Growth, Differentiation, and Ploidy with Reduced Proliferation of Right Ventricular Cardiomyocytes in Children with Congenital Heart Defect Tetralogy of Fallot.

The myocardium of children with tetralogy of Fallot (TF) undergoes hemodynamic overload and hypoxemia immediately after birth. Comparative analysis of changes in the ploidy and morphology of the right ventricular cardiomyocytes in children with TF in the first years of life demonstrated their significant increase compared with the control group. In children with TF, there was a predominantly diffuse distribution of Connexin43-containing gap junctions over the cardiomyocytes sarcolemma, which redistributed into the intercalated discs as cardiomyocytes differentiation increased. The number of Ki67-positive cardiomyocytes varied greatly and amounted to 7.0–1025.5/106 cardiomyocytes and also were decreased with increased myocytes differentiation. Ultrastructural signs of immaturity and proliferative activity of cardiomyocytes in children with TF were demonstrated. The proportion of interstitial tissue did not differ significantly from the control group. The myocardium of children with TF under six months of age was most sensitive to hypoxemia, it was manifested by a delay in the intercalated discs and myofibril assembly and the appearance of ultrastructural signs of dystrophic changes in the cardiomyocytes. Thus, the acceleration of ontogenetic growth and differentiation of the cardiomyocytes, but not the reactivation of their proliferation, was an adaptation of the immature myocardium of children with TF to hemodynamic overload and hypoxemia.

Morphofunctional state of the myocardium in children with various variants of elevated blood pressure

Morphofunctional state of the myocardium in children with various variants of elevated blood pressure

ОЦЕНКА ПОКАЗАТЕЛЕЙ СЕГМЕНТАРНОЙ ДЕФОРМАЦИИ МИОКАРДА ЛЕВОГО ЖЕЛУДОЧКА У ДЕТЕЙ С ГИПЕРТРОФИЧЕСКОЙ КАРДИОМИОПАТИЕЙ

Assessment of segmental myocardial strain is a promising and relevant direction in the diagnosis of early impairments of left ventricular (LV) contractility in children with hypertrophic cardiomyopathy (HCM). Objective of the study: to assess the indicators of segmental myocardial strain in children with HCM. Materials and methods of research: prospective, open-label, nonrandomized, controlled. 61 patients with asymmetric HCM aged 7 to 17 years (median 9 [7,6; 13,2]) underwent echocardiography according to the standard technique with the determination of segmental longitudinal, radial, circular LV myocardium in 2D speckle tracking mode. 45 (74%) children had a non-obstructive form (NF) of HCM, 16 (26%) children had an obstructive form (OF). Obstruction was detected at the level of the LV outflow tract with a pressure gradient of 30-50 mm Hg. Results: when assessing segmental myocardial strain, a decrease in longitudinal strain was found less than the normative values in the antero-septal, anterior, antero-lateral segments in children with NF HCM with a compensatory increase in strain values in the contralateral segments (inferior septal, inferior lateral and lower ). In similar segments in children with OF, there was a significant decrease in deformity, while in the contralateral segments a less pronounced compensatory increase in deformity was determined, as well as a decrease in the minimum values of strain indicators. Assessment of segmental radial and circular strain, a statistically significant predominance of indicators in all segments, except for anterolateral, in the group with NF compared to the OF HCM was determined. A decrease in strain in the antero-septal, anterior, antero-lateral segments was found, but less pronounced compared to the indicators of longitudinal strain, as well as a compensatory increase in strain in the antero-septal values in the contralateral segments (inferior septal, inferior lateral and inferior). It has been found that the assessment of global strain values widely used in clinical practice might not be optimal enough, since too many segmental strain values are discarded and averaged, which are unevenly distributed, and therefore the assessment of strain in each segment of the myocardium in children with an asymmetric form of HCM acquires important diagnostic value. Conclusion: changes in the indicators of segmental myocardial strain reflect violations of LV contractile function and are most pronounced in OF compared with NF HCM. Their study in children is important for the timely initiation of therapy and improving the prognosis of the disease.

Myocardial Expression of Estrogen Receptor-mRNA Is Associated With Lower Markers of Post-operative Organ Damage in Young Patients With Congenital Cardiac Defect.

Background: Estrogen receptors (ERs) relate to cardio-protection in adults, but their role in younger patients is not known. We aimed to assess the myocardial expression of ERα- and ERβ- mRNA in young patients with congenital cardiac disease and to analyze their putative protective role.Patients and Methods: Twenty children and young adults (seven females and 13 males) with a median age of 13.8 years (interquartile range: 12.3 years) were enrolled in this prospective study. The myocardial expression of ER-mRNA and genes involved in inflammation, growth, and stress response was assessed by real-time PCR and was correlated to post-operative (po) outcome.Results: ER-mRNA was detected in the myocardium of all patients, independently of gender and age. The expression of ER-mRNA correlated with that of mRNA coding for brain natriuretic peptide and for all cytokines tested. A higher ERα-mRNA expression correlated with lower troponin T concentrations at 24 h po (p = 0.032), higher PaO2/FiO2 ratio at 4 h po (p = 0.059), lower fluid retention at 4 h po (p = 0.048), and lower aspartate aminotransferase (AST) levels at 24 h po (p = 0.047). A higher ERβ-mRNA expression was also correlated with lower fluid retention at 24 h po (p = 0.048).Patients in whom the levels of ERα- and ERβ-mRNA were >P50 had lower troponin T (p = 0.003, respectively) and lower AST concentrations at 24 h po (p = 0.043, respectively) than the others.Conclusions: The expression of ERα- and ERβ-mRNA is present in the myocardium of children and young adults with congenital cardiac defect and is associated with lower markers of po organ damage. This suggests that ERs may provide perioperative organ protection in this population.

Left ventricular myocardial strain and electrocardiographic changes in children with hypertrophic cardiomyopathy

Abstract Introduction. Hypertrophic cardiomyopathy is one of the most common diseases of the myocardium in children. Meanwhile, the relationship between indicators of strain and electrocardiographic changes, their diagnostic significance for children with hypertrophic cardiomyopathy remains an insufficiently well-studied issue.Purpose.Тo analyze the relationship between indicators of strain of the left ventricular and ECG in children with hypertrophic cardiomyopathy (HCM).Materials and methods. Have been examined 61 patients with an asymmetric form of hypertrophic cardiomyopathy aged from 7 to 17 years. Of these, 45 (73.8%) children with nonobstructive form, 16 (26.2%) children with obstructive form. Electrocardiography (ECG) and 24-hour Holter monitoring ECG had performed. The parameters of global longitudinal, radial and circular of the left ventricular myocardial strain and their rates had determined by echocardiography in the 2D speckle tracking modeResults. In children with HCM, ECG signs of hypertrophy were studied (deviation of the electrical axis to the left, the predominance of the R wave in lead I, V6 over the S wave, the predominance of the S wave in lead V1 over the R wave) and myocardial ischemia (inversion of the T wave and a decrease in the ST segment in the leads I, II, V5, V6), rhythm and conduction disorders (ventricular extrasystole, degree I atrioventricular block, expansion of the QRS complex in leads V1-V3, incomplete blockade of the anterior left branch of the His bundle, increased duration of terminal activation), which significantly prevailed in obstructive form versus non-obstructive form. A decrease in the global longitudinal, radial, circular strain of the left ventricular myocardium and their rates had found, which had significantly more pronounced in the group with obstructive HCM. Inverse correlations had found between the parameters of strain and ECG-signs of hypertrophy and myocardial ischemia, conduction disorders, more pronounced between the parameters of longitudinal strain and ECG with a significant predominance in the obstructive form of the disease.Conclusions. In children with obstructive HCM, compared with the non-obstructive form, there have significantly more pronounced signs of myocardial hypertrophy and ischemia, rhythm and conduction disorders on the ECG and with 24-hour Holter monitoring ECG.

Myocardial Fibrosis in Pediatric Patients With Ebstein's Anomaly.

Left ventricular dysfunction in Ebstein's anomaly (EA) is associated with higher mortality. The health of the left ventricular myocardium in children and adolescents with EA has not been investigated in detail. Patients with unrepaired EA who had undergone cardiac magnetic resonance imaging including T1 mapping were retrospectively reviewed. Patients were compared with age- and sex-matched controls. EA severity index was calculated using volumetric measurements at end diastole ([right atrial+atrialized right ventricular volumes]/[functional right ventricular+left atrial+left ventricular volumes]). Global circumferential and radial strain and as well as strain rate were examined using cardiac magnetic resonance feature tracking. Twelve EA patients and an equal number of controls were included. Functional and atrialized right ventricular end-diastolic volumes were 84±15 and 21±13 mL/m2, respectively. Late gadolinium enhancement, confined to the right ventricle, was found in 2 patients (16%). Left ventricular native T1 values and extracellular volume fractions were higher in patients compared with controls (1026±47 versus 956±40 ms, P=0.0004 and 28.5±3.4% versus 22.5±2.6%, P<0.001, respectively). Native T1 times correlated inversely with patients' age, body surface area, and O2 saturations (r=-0.63, -0.62, and -0.91, respectively; P=0.02, P=0.02, and P<0.0001, respectively). EA severity index ranged between 0.15 and 0.94 and correlated with T1 values (r=0.76, P=0.003). Native T1 correlated with global circumferential strain (r=0.58, P=0.04) but not ejection fraction (EF). EA patients had reduced maximum oxygen uptake (Vo2max). Vo2max correlated inversely with T1 values (r=-0.79, P=0.01). Children and adolescents with EA experience an abnormal degree of diffuse myocardial fibrosis. Its association with O2 saturation points toward a role of hypoxemia in the pathogenesis of fibrosis. Larger and prospective studies are needed to evaluate the value of T1 mapping for risk stratification and monitoring in EA.

2D speckle-tracking assessment of left ventricular myocardial strain in healthy children and adolescents

Introduction . To determine the relevant indicators of strain and strain rate of the left ventricular myocardium in children and adolescents. Materials and methods. Have been examined 67 patients form aged from 7 up to 17 years old. 1-st group – 30 children from 7 to 11 years old; 2-nd group – 37 adolescents from 12 to 17 years old. Аt an echocardiographic examination the systolic function of the left ventricle was determined: ejection and shortening fractions, in 2D-speckle-tracking mode – global and segmental longitudinal, circular and radial strain and strain rates. Results . Have been studied the relevant indicators of global and segmental longitudinal, radial, circular deformities of the left ventricular myocardium and their rates in healthy children and adolescents. A statistically significant increase in global and segmental longitudinal strain, radial and circular strain rates in the 2-nd group compared with the 1-st group had revealed. Had found that the uniform distribution of indicators in the ranges of confidence intervals, noted in the assessment of global radial strain and circular strain rate, as well as a statistically significant predominance of strain indicators in the subendocardial layers compared with the subepicardial layers of the myocardium left ventricle. Conclusions. 1. In adolescents 12–17 years old, compared with children 7–11 years old, there is a statistically significant predominance of global and segmental longitudinal strain, radial and circular strain rates of the left ventricular myocardium. Radial strain and circular strain rate of the left ventricular myocardium are the most uniform in contrast to other indicators of strain. 2. In healthy children and adolescents, had observed statistically significant higher strain and strain rate in the subendocardial layer compared to the subepicardial layer of the myocardium. 3. The obtained indicators of global and segmental myocardial strain can serve as normative for children and adolescents in assessing the systolic function of the left ventricle.

Assessment of the potential damaging effect of radiofrequency exposure in children in prospective follow-up (case report series)

Aim: To evaluate the electrical activity of the myocardium and the radiofrequency (RF) application zone resulting from radiofrequency ablation (RFA) performed at an early age.Material and Methods. A prospective follow-up study included three patients who underwent intracardiac electrophysiological study (EPS) and effective RFA of the tachycardia for the first time at an early age. A reintervention was required in one case 12 years after the procedure and in two cases six years after it due to recurrent and new-onset arrhythmias. During the reintervention, electroanatomical mapping was performed to assess the potential damaging effect of radiofrequency exposure in the area of the first ablation.Results. The intracardiac EPS and amplitude bipolar CARTO-reconstruction of primary ablation area were performed during repeated RFA procedure. The study showed that neither zones with a decrease in the amplitude of electrical signal from the myocardium nor silent electrical zones were present ruling out the cicatricial-sclerotic changes in the myocardium in children in the long-term period after RF exposure.Conclusion. The study showed that no increase in the coagulation necrosis zone in the area of primary ablation occurred during the growth of child when the sparing energy and temperature parameters of RFA and the limited number of RF applications were used. Further research in this area is required.

Telocytes in the Myocardium of Children with Congenital Heart Disease Tetralogy of Fallot.

Telocytes, a new type of interstitial stem cells with long thin processes that form a three-dimensional network around cardiomyocytes, vessels, and nerve fibers were described in the myocardium of children with tetralogy of Fallot. Two types of morphologically different telocytes, spindle-shaped and rounded, were identified. Contacts of telocytes with stem cells and interstitial macrophages were found. Telocytes were more common in the immature myocardium, where the assembly of myofibrils in cardiomyocytes was not completed and small Ki-67+ cardiomyocyte progenitor cells were present. Telocytes expressed immunohistochemical markers CD117, vimentin, CD34, and CD44. Localization and ultrastructural characteristics of telocytes suggested their participation in stem cell differentiation, coordination of neoangiogenesis, and paracrine regulation of all components of the interstitium.

Acute myocarditis in children: problems of diagnosis and treatment

Acute myocarditis by the World Health Organization is an inflammatory disease of the heart muscle, confirmed by histologically, immunologically and immunohistochemically. The diagnosis of acute myocarditis in children remains open due to the presence of a number of reasons. First of all, it is difficult to diagnose myocarditis in children due to the variety of clinical manifestations and the presence of nonspecific symptoms of the disease. What matters is the lack of accessibility in the routine practice of a doctor of certain research methods and a sharp limitation in the use of endomyocardial biopsy. The search for differential diagnostic algorithms of the disease continues. According to modern literature, much attention is paid to non-invasive methods for the diagnosis of acute myocarditis in children. The course of acute myocarditis can be complicated by life-threatening cardiac arrhythmias: ventricular extrasystole, lengthening of the corrected QT interval, atrioventricular block. The appearance of cardiac arrhythmias increases the risk of sudden cardiac death. Recommendations for the treatment of myocardium in children often undergo changes due to the small number of multicenter and controlled studies in the pediatric population. The article provides an overview of modern approaches to the treatment of acute myocarditis in children: the use of antiviral drugs, intravenous immunoglobulin, immunosuppressive therapy, especially the treatment of heart failure in acute myocarditis in children.

SUN-090 STRUCTURAL AND FUNCTIONAL (SYSTOLIC) MYOCARDIAL DYSFUNCTION AND THEIR CORRELATION WITH BLOOD PRESSURE, HEMOGLOBIN AND PARATHORMONE LEVEL IN CHILDREN WITH END STAGE RENAL DISEASE

Myocardial dysfunction is the leading cause of morbidity in children with end stage renal disease (ESRD) and mostly associated with hypertension, anemia and high parathormone (PTH) level. Not only functional but also structural myocardial changes play a role in this event. But these changes are not very well studied in our population. So, with a view of answering the research question, what are the structural and functional changes in myocardium in children with ESRD, we designed this study. Thirty diagnosed children with ESRD (based on eGFR <15ml/min/1.73m2) were included purposively in this prospective cross sectional study in the department of pediatric nephrology of a tertiary care hospital in Bangladesh over 1 year period (from January 2017 to December 2017). All the patients underwent color Doppler echocardiography for evaluation for structural and functional (systolic) cardiac abnormalities. Thirty age and sex match healthy children were taken as comparison and also to get normal echocardiographic findings. Left atrial diameter (LA), left ventricular internal diameter in systole (LVIDs) and diastole (LVIDd), left ventricular posterior wall thickness in systole (LVPWs) and diastole (LVPWd) were considered as structural variables, ejection fraction (EF) and fractional shortening (FS) were considered as systolic function variable. Correlation of blood pressure (BP), hemoglobin (Hb) and PTH level with structural and functional variable were also observed in the study subjects. Twenty one (70%) children were male and 9 (30%) were female and their mean age at presentation was 12.23±3.20 year. Mean systolic BP was 120±16 mm Hg and mean diastolic BP was 77±14 mm Hg, mean Hb level was 8.00±1.48 gm/dl and mean serum PTH level was 548.46±309.01. Echocardiographic findings revealed statistically significant difference in case and comparison group in relation with LA, LVIDd, LVIDs, LVPWs and LVPWd (p<0.001) but no difference in relation to FS (p=0.934) and EF (p=0.754). There was negative correlation of BP, Hb and PTH level with EF (r=-0.098, -0.107 and -0.045 respectively) and FS (r=-0.123, -0.271 and -0.169 respectively) but not statistically significant. BP and PTH level was positively correlated with LVIDs (r=0.099, 0.097) and LVIDd (r=0.109, 0.074) though not statistically significant. Positive correlation was observed between Hb level with LVIDd and LVIDs and was statistically significant (r= 0.518, p=0.016 and r=0.044, p=0.046 respectively). It can be concluded from present study that children with ESRD are prone to develop cardiac dysfunction specially left ventricular structural abnormality and there is negative correlation of BP, Hb and PTH level with functional change and positive correlation of with structural change.

Non-compaction of ventricular myocardium in children

Non-compaction of ventricular myocardium (NVM), a rare congenital and inherited cardiomyopathy, is characterized by prominent trabeculations and deep intertrabecular recesses in communication with the ventricular cavity.NVM has diverse clinical presentations without specificity, of which the major characteristics are cardiac insufficiency, arrhythmias and thrombosis.Echocardiography and cardiac magnetic resonance imaging are necessary technologies to diagnose NVM.Symptomatic therapy is the only choice for most patients.Furthermore, if medical treatment fails, the heart transplantation could be performed.As a whole, NVM has a high mortality and entirely different prognosis, however, the prognosis of asymptomatic patients is relatively good. Key words: Non-compaction of ventricular myocardium; Cardiac insufficiency; Arrhythmia; Thrombosis

Advances in noncompation of the ventricular myocardium in children

Noncompation of the ventricular myocardium is one of three major types of cardiomyopathy in children.More patients are diagnosed, with the understanding of this cardiomyopathy.Their clinical manifestation may vary a lot from without symptoms to severe cardiac dysfunction.This article describes the clinical characteristics of left ventricular noncompaction(LVNC)children and long-term prognosis of children at different ages.With the development of next-generation sequencing technology, more and more gene mutations have been found to cause LVNC.The article introduces the relationship between genotypes and clinical phenotypes in children.LVNC has poor long-term prognosis.At present, studies have showed the importance of family screening.For children carrying pathogenic genes mutations, they should be followed-up regularly even without clinical symptoms. Key words: Noncompation of the ventricular myocardium; Prognosis; Genotype; Phenotype

Determination of signal calcineurin pathway biomarkers significance in early myocardial changes in children with bicuspid aortic valve

Aim of research: determination of the diagnostic value of serum concentration of biomarkers of calcineurin signal pathway (calcineurin, protein S100, interleukin-2) in children with the bicuspid aortic valve at absence of heart failure signs and influence of revealed changes on the early remodeling and hypertrophy of myocardium.Materials and methods: 38 children with the bicuspid aortic valve (SAV), diagnosed by doppleroechocardiography, and 28 children of the control group underwent the measuring of concentrations of calcineurin, protein S100, interleukin-2 and general calcium by the immune-enzyme method with the further estimation of the influence of these changes on morphofunctional hearth parameters by the method of correlation analysis.Results: children with SAV demonstrated the reliable thickening of the back wall of the left ventricle and interventricular septum at the correspondent increase of the blood velocity and pressure gradient on the aortic valve. Serum concentrations of calcineurin and calcium in children with SAV were reliably decreased, and protein S100 correspondingly increased comparing with the control group. At that the SAV group, as opposite to the control one, demonstrated reliable negative correlations between the calcineurin level and right ventricle sizes, protein S100 and left and right atria sizes interleukin-2 and left ventricle systolic size at the reliable positive correlation between levels of calcineurin and general calcium.Conclusions: Children with SAV demonstrated the moderately expressed left ventricle myocardium hypertrophy, decrease of calcineurin serum concentrations that have a negative influence on the geometry of right heart parts and serum calcium level at the correspondent increase of protein S100. The revealed changes allowed to establish the predicative role of calcineurin in the development of early morphofunctional changes of myocardium in children with SAV

Myocardial Fistulisation and Coronary Arterial Ectasia in Children with Univentricular Circulation: An Under-Recognised Problem.

Among 241 children with univentricular circulation who underwent total cavopulmonary connection (Glenn or Fontan) over a 17years period (January 2000-April 2017), we found two patients who had diffuse coronary fistulisation of their myocardium (0.8%). We also report an additional third case from Oak Lawn, Illinois, USA. One of the children had documented normal coronary arteries and myocardium at catheterisation prior to development of the fistulisation process. The same child also developed extensive veno-venous collaterals. All children had evidence of elevated pulmonary arterial pressures and were treated with a combination of pulmonary vasodilators. The presence of chronic hypoxaemia and elevated filling pressures could potentially have contributed to coronary endothelial dysfunction, thereby giving rise to the coronary vasculopathy and myocardial fistulisation. Alternatively, this myocardial fistulisation process may be present from early in life and not recognised. This may necessitate early referral for orthotopic cardiac transplantation. Diffuse fistulisation of the myocardium in children and young adults with univentricular circulation may be an under-recognised occurrence and coronary angiography should be considered in these patients.

Effect of transcatheter closure of secundum atrial septal defect on cardiac electric remodeling

Purpose: This study aimed to investigate the intermediate- and short-term effects of transcatheter secundum atrial septal defect (ASD) closure on cardiac electric remodeling in children and adults. Methods: Fifty patients with secundum ASD referred for possible transcatheter device closure were subjected to history taking, proper physical examination, electrocardiographic assessment, and transthoracic echocardiographic examination and were evaluated before the ASD closure, 1 day, 3 months, and 6 months after closure. Results: During the 6-month follow-up, electrocardiographic parameters of remodeling were improved. P dispersion decreased from 49.73 ± 9.01 ms to 30.53 ± 5.08 ms (P = 0.004), QT dispersion decreased from 67.60 ± 5.31 to 51.13 ± 5.73 ms (P = 0.003), QRS duration decreased from 134.40 ± 4.97 ms to 116.20 ± 3.47 ms (P = 0.002), and PR interval decreased from 188.87 ± 6.06 ms to 168.00 ± 6.16 ms (P = 0.002). Electric remodeling was associated with remodeling of the cardiac chambers. At the end of follow-up, the right ventricular (RV) end-diastolic dimension decreased from 25.67 ± 5.50 mm to 17.80 ± 2.70 mm (P = 0.001) the left ventricular end-diastolic dimension increased from 33.17 ± 6.44 mm to 37.53 ± 5.15 mm (P = 0.002), mean pulmonary artery pressure decreased from 16.97 ± 3.37 mmHg to 9.22 ± 1.37 mmHg (P = 0.000), and RV systolic pressure decreased from 30.77 ± 4.69 mmHg to 18.8 ± 2.11 mmHg. After 6 months, 93.3% of the patients had normal RV size. Conclusion: Transcatheter ASD device closure leads to a significant improvement in the right-sided chambers' dimension and function and can reverse electrical changes in atrial and ventricular myocardium in children and adults after correcting hemodynamic status in short- and intermediate-term follow-up.

MYOCARDIAL 2D STRAIN AND STRESSES INDICES IN THE DETECTION OF CARDIOTOXICITY IN CANCER SURVIVORS

Doxorubicin-based chemotherapy is an effective treatment for cancer, however its successes are hindered by its alterations of myocardial physiology at multiple stages. From molecular scale up to morphological and functional scale, the induction of multiple cardiotoxicities is reported. Accurate estimation of myocardial strains and stresses requires accurate tracking of myocardial displacements. However, the heart is relatively complex to track since it has much fewer anatomical landmarks than other organs. In this context, the aim of this study was to develop a method based on cine MRI and finite element modeling of the heart to evaluate mechanical properties changes within the myocardium in children receiving doxorubicin therapy for leukemia.