Diastolic function in anthracycline-treated children.

BACKGROUND: Anthracyclines are effective medications for childhood cancer. Their limitation is the risk of cardiomyopathy. Although diastolic dysfunction has been described in patients who received anthracyclines, cardiac monitoring has focused on systolic function, which is abnormal in up to 41% of the patients. We conducted a study to assess diastolic function utilising transmitral inflow Doppler velocities and tissue Doppler imaging in anthracycline-treated children 5 years post-therapy. METHODS: This was a retrospective study on 63 anthracycline-treated patients. Echocardiographic parameters included peak early and late transmitral inflow Doppler velocities (E, A), E/A ratio, E deceleration time, and tissue Doppler imaging early and late diastolic mitral annulus velocities (E', A'), E/E' ratio, and E'/A' ratio. RESULTS: All indices of diastolic function that we measured were normal in the anthracycline-treated patients. CONCLUSION: We conclude that diastolic function assessed by transmitral inflow Doppler velocities and tissue Doppler imaging is normal in anthracycline-treated children 5 years after completion of treatment. Further longitudinal study is needed to determine whether diastolic function becomes abnormal with time in this patient population.

Vitamin D deficiency is associated with increased left ventricular mass and diastolic dysfunction in children with chronic kidney disease.

Cardiovascular disease currently is the leading cause of morbidity and mortality among patients with chronic kidney disease (CKD). Abnormalities in arterial compliance, increased left ventricular mass, and diastolic dysfunction are some of the recognized cardiovascular complications observed in these patients. This study explored the relationship between various parameters of calcium-phosphorus metabolism including 25-hydroxy vitamin D and cardiovascular structure and function in pediatric patients with CKD. This cross-sectional study was conducted using a cohort of 34 children with CKD who had no history of underlying congenital or structural cardiac disease. Two-dimensional echocardiography was used to measure the left ventricular mass index (LVMI), E/A ratio, E', E/E' ratio, and myocardial performance index (MPI). The augmentation index (AI), derived via radial artery tonometry, was used as an indirect measure of central aortic stiffness. Serum biochemical markers of calcium-phosphorus metabolism were simultaneously measured. Univariate analysis showed that LVMI correlated with 25-hydroxy vitamin D (r = -0.54; p < 0.05), systolic blood pressure (SBP) (r = 0.36; p < 0.05), and AI (r = 0.26; p < 0.05). Serum-intact parathyroid hormone (PTH) levels correlated with the E/E' ratio (r = 0.63; p < 0.05) and E' (r = -0.61; p < 0.05). Multiple regression analysis showed that 25-hydroxy vitamin D and SBP were independent predictors of increased LVMI and that PTH was an independent predictor of diastolic dysfunction. This is the first study investigating pediatric patients with CKD that suggests an etiology of nutritional vitamin D deficiency associated with increased left ventricular mass and diastolic dysfunction. The cardiovascular changes observed are not easily reversible. Hence, early preventive therapy with vitamin D supplementation is advocated.

Vitamin D deficiency and arterial wall stiffness in children with chronic kidney disease.

Arterial wall stiffness is a recognized complication in children with chronic kidney disease (CKD). Vascular abnormalities in these patients are shown to predate cardiac abnormalities such as left ventricular hypertrophy and diastolic dysfunction. The etiology of vascular abnormalities in these patients currently is not clear. This study explored the relationship between various parameters of calcium-phosphorus metabolism including 25-hydroxy vitamin D and arterial wall stiffness in pediatric patients with CKD. This study investigated a cohort of 43 children with CKD who had no history of underlying congenital or structural cardiac disease. The Augmentation Index (AI), a measure of peripheral arterial reflective properties using radial artery tonometry, was used as an indirect measure of central aortic stiffness. Serum biochemical markers of calcium-phosphorus metabolism were simultaneously measured. Univariate testing showed that AI correlated with worsening kidney function. Serum 25-hydroxy vitamin D levels were low and correlated negatively with AI (r = -0.39; p < 0.05). Multiple regression analysis showed that 25-hydroxy vitamin D was the only significant independent predictor of increased central arterial stiffness in the subgroup of children receiving hemodialysis. No association was observed between AI and any other measured biochemical parameter of calcium-phosphorus metabolism. This is the first study to investigate pediatric patients with CKD that suggests an association between nutritional vitamin D deficiency and increased arterial stiffness in children with CKD. The pathophysiologic mechanisms of vitamin D that regulate increased arterial stiffness need to be integrated further in pediatric CKD patients.

Cardiomyopathies encountered commonly in the teenage years and their presentation.

Cardiomyopathy encompasses a broad range of inherited and acquired abnormalities affecting the myocardium. This heterogeneous group of disorders is an important cause of morbidity and mortality in the adolescent patient as a result of the presence of systolic or diastolic dysfunction, as well as the risk of coexisting arrhythmias and sudden cardiac death. It is important for the primary care physician involved in the care of adolescents to understand the different causes of cardiomyopathy and their typical clinical presentations. The cause, pathogenesis, clinical presentation, and diagnostic evaluation for adolescents with cardiomyopathy are reviewed. An overview of treatment modalities is also presented.

Functional critical aortic stenosis with transient retrograde flow in a neonate with left diaphragmatic hernia.

We report a neonate with left congenital diaphragmatic hernia and severe left ventricular dysfunction, in whom the blood flow in the transverse arch and its branches was supported in a retrograde fashion by patent ductus arteriosus. There was only minimal antegrade flow across the aortic valve and hemodynamic physiology resembled critical aortic stenosis, necessitating the immediate use of prostaglandin E1 infusion to maintain the patent ductus arteriosus.

Anomalous left coronary artery from the pulmonary artery with a large patent ductus arteriosus: aversion of a catastrophe.

We present an infant who had an anomalous left coronary artery arising from the pulmonary artery (ALCAPA) and a large patent ductus arteriosus (PDA), who was diagnosed before a potentially catastrophic closure of PDA. In the presence of normal left ventricular function and the absence of coronary artery collaterals, it is difficult to diagnose ALCAPA. A disproportionate degree of left ventricular dilation and severity of mitral valve regurgitation relative to the degree of PDA shunt, and echogenic papillary muscles on an echocardiogram should raise a suspicion of coronary artery anomalies. The infant underwent surgical ligation of PDA with translocation of coronary arteries and had an uneventful recovery.

Predictors of left ventricular remodeling after aortic valve replacement in pediatric patients with isolated aortic regurgitation.

OBJECTIVE: To identify the risk factors that could predict postoperative outcome after aortic valve replacement in pediatric patients with isolated aortic regurgitation (AR). BACKGROUND: There is controversy regarding the appropriate timing of surgery in asymptomatic or minimally symptomatic patients with isolated AR. In the pediatric age group, there are limited studies in this regard and most of them are on combined aortic valve stenosis and regurgitation. METHODS: All patients with biventricular physiology and morphologic left ventricle (LV) who underwent aortic valve surgery for AR from January 1988 to July 2010 were included in the study. Demographic, clinical, and echocardiographic data were collected at presurgical visit, early postoperative, 1 year, and most recent follow-up. RESULTS: Among 53 patients (36 males), 18 had LV end-diastolic diameter (LVEDD) z-score >4 standard deviation (SD) (group I) and 35 had LVEDD <4 SD (group II). Forty-one had long-term follow-up. Mean age at surgery was 11.6 ± 5.9 years; mean follow-up was 6.9 ± 5.6 years. Preoperative LVEDD >4 SD predicted persistent LV dilation (>2 SD) at early post-op (P < .05) and 1 year follow-up (P = .09). Preoperative decreased LV function (fractional shortening <28%) was the only significant predictor of persistent LV dysfunction at most recent follow-up and requirement for repeat interventions (P < .01). Most have reduction of LV dimensions in the immediate postoperative period to normal limits. CONCLUSION: In children with AR, preoperative LV dysfunction and extreme LV dilation (>4 SD) are significant predictors of incomplete LV remodeling or persistent LV dysfunction.

Mitral valve surgery for severe mitral regurgitation and dilated cardiomyopathy--a bridge to transplant: case report and a review of literature.

We report a child with myocardial necrosis, dilated cardiomyopathy, and severe mitral valve (MV) regurgitation following neonatal enteroviral myocarditis. He underwent MV annuloplasty at 18 months and MV replacement at 3 years of age. He remains asymptomatic on medical therapy at 8 years of age. Mitral valve surgery may stabilize the evolution of dilated cardiomyopathy and delay the ultimate need for heart transplant.

Left ventricular systolic dyssynchrony in pediatric and adolescent patients with congestive heart failure.

BACKGROUND: Echocardiographic measures of left ventricular (LV) dyssynchrony in pediatric patients with heart failure (HF) have not been adequately evaluated. The aim of this study was to evaluate LV systolic dyssynchrony in pediatric patients with HF and normal children. METHODS: Among a total of 68 patients, 22 had HF and 46 were normal. Doppler tissue imaging, M-mode echocardiography, and pulsed-wave Doppler echocardiography were performed. Intraventricular dyssynchrony using the maximal difference in time to peak myocardial systolic contraction (Ts), the standard deviation of Ts of 12 LV segments, septal-to-posterior wall motion delay, and interventricular dyssynchrony by measuring aortic and pulmonary pre-ejection delays were obtained. RESULTS: The maximal difference in Ts (patients with HF, 91.27 ± 31.18 msec; controls, 45.93 ± 21.29 msec; P < .001), the standard deviation of Ts (patients with HF, 31.05 ± 10.68 msec; controls, 15.60 ± 7.70 msec; P < .001), septal-to-posterior wall motion delay (patients with HF, 117.14 ± 45.18 msec; controls, 48.69 ± 16.63 msec; P < .001) and interventricular dyssynchrony (patients with HF, 21.60 ± 16.27 msec; controls, 11.56 ± 9.38 msec; P = .03) were significantly prolonged in the HF group. Defining systolic dyssynchrony as a standard deviation of Ts > 31 msec (+2 standard deviations of normal controls) and a maximal difference in Ts > 89 msec in normal controls and 18 patients with HF due to dilated cardiomyopathy was included for analysis of systolic dyssynchrony; it was present in three (6.5%) and two (4.3%) controls and in nine (50%) and 10 (55%) patients with HF due to dilated cardiomyopathy, respectively. Low ejection fraction, elevated LV end-diastolic volume, and elevated LV end-systolic volume had significant correlations with systolic dyssynchrony. QRS duration was not significantly correlated with measures of dyssynchrony. CONCLUSIONS: Systolic mechanical dyssynchrony is common in pediatric patients with HF. QRS duration is not a determinant of systolic dyssynchrony in pediatric patients. Echocardiographic measurements of systolic dyssynchrony are feasible in pediatric patients.

Central venous catheter-associated pericardial tamponade in a 6-day old: a case report.

Introduction. Pericardial effusion (PCE) and tamponade can cause significant morbidity and mortality in neonates. Such cases have been reported in the literature in various contexts. Case Presentation. A 6-day old neonate with meconium aspiration syndrome and persistent pulmonary hypertension of newborn on high frequency oscillator ventilation and inhaled nitric oxide was referred to our hospital with a large pericardial effusion causing hemodynamic compromise. Prompt pericardiocentesis led to significant improvement in the cardio-respiratory status and removal of the central line prevented the fluid from reaccumulating. Cellular and biochemical analysis aided in the diagnosis of catheter related etiology with possibility of infusate diffusion into the pericardial space. Conclusion. We present this paper to emphasize the importance of recognizing this uncommon but serious complication of central venous catheters in intensive care units. We also discuss the proposed hypothesis for the mechanism of production of PCE.

Measuring stress velocity index using mean blood pressure: simple yet accurate?

The stress velocity index, or the relationship of the rate-corrected mean velocity of circumferential shortening (VCFc) to the end systolic wall stress (ESWS), is a sensitive, load-independent measure of left ventricular contractility. ESWS is technically difficult to obtain and requires simultaneous blood pressure measurement, carotid artery tracing, and phonocardiogram. We report our comparison of two simpler methods of measuring ESWS and, therefore, stress velocity index. Patients with normal cardiac anatomy who had completed anthracycline chemotherapy were evaluated. ESWS as measured by the standard method using a carotid artery tracing (ESWScar) was compared to ESWS obtained using mean arterial pressure (ESWSmap) or systolic blood pressure (ESWSsbp). The cohort included 63 patients, with 37 (59%) males and a median age of 13.1 years. The mean (+/-SD) ESWScar was 53.3+/-15.3 g/cm(2) (range, 26.3-94 g/cm(2)); ESWSmap, 53 +/-13.4 g/cm(2) (range, 27.1-86.1 g/cm(2)); and ESWSsbp, 72.9 +/- 18.2 g/cm(2) (range, 40.8-117.2 g/cm(2)). ESWSmap and ESWSsbp closely correlated with ESWScar (coefficient correlation r = 0.88 and r = 0.87, respectively). Using ESWSmap, all patients were correctly classified as having normal or abnormal contractility as defined by stress velocity index, whereas ESWSsbp detected only two of the six patients with impaired contractility. We conclude that ESWSmap is a simple, highly sensitive and specific method for assessing left ventricular contractility. ESWSmap correlates closely with ESWScar and can be incorporated into the monitoring of cardiac dysfunction in the anthracycline-treated population. Further studies are needed to determine if this simplified measure accurately assesses the ESWS in other cardiac disease states.

Infants and children with tachycardia: natural history and drug administration.

Tachyarrhythmias can occur at any age from the developing fetus through adulthood. However, in deference to adult-onset ischemic cardiac issues, abnormal heart rhythms occurring in the young are often due to developmental alterations of the cardiac conduction tissue, genetically-inherited changes of myocardial cellular ion membrane properties and both pre- and post-surgical repair of associated structural congenital heart anatomical defects. And different from adults, abnormal rhythms occurring in the young can spontaneously disappear with progressive patient growth. Both supra- and ventricular tachyarrhythmias occur in the young although atrial rhythm abnormalities far exceed those of the ventricle. In both, pharmacologic therapies to alter tissue conduction and refractoriness remain the mainstay for initial intervention in the infant and young child, reserving more invasive and potentially harmful ablation therapies for drug-refractory cases. The purpose of the review is to present common and uncommon tachyarrhythmias which can occur in the fetus and throughout infancy. Emphasis will be placed on their electrocardiographic identification, recognition of any associated structural congenital heart defects and recommended pharmacologic management. Drug therapies will be divided according to mechanism of action and discussions of which particular agent is potentially best-suited to treat which specific tachyarrhythmia. A listing of current pharmacologic agents used in the young with appropriate dosages is included.

Regression equations for calculation of z scores of cardiac structures in a large cohort of healthy infants, children, and adolescents: an echocardiographic study.

BACKGROUND: Decision making in the care of pediatric patients with congenital and acquired heart disease remains reliant on detailed measurements of cardiac structures using 2-dimensional echocardiography. Calculated z scores are often used to normalize these measurements to the patient's body size. Existing normal data in the literature are limited by small sample size, small numbers of measured cardiac structures, and inadequate data for the calculation of z scores. Accordingly, we sought to develop normative data in a large pediatric cohort using modern echocardiographic equipment from which z scores could be calculated. METHODS: Two-dimensional and M-mode echocardiography was performed in 782 patients ranging in age from 1 day to 18 years. Measurements were made of 21 individual cardiac structures. Regression equations were derived to relate the size of the various cardiac structures to body surface area. Data are presented graphically, and regression equations are derived relating cardiac dimension to body surface area. CONCLUSION: The presented data will allow the calculation of z scores for echocardiographically measured cardiac structures. This information will be valuable for clinicians caring for infants and children with known or suspected cardiac disease.

Atrioventricular septal defect with common atrioventricular junction, common arterial trunk, and severe coarctation of the aorta in a patient with Down's syndrome.

Atrioventricular septal defect with common atrioventricular junction is rarely associated with either a common arterial trunk or coarctation of the aorta. We report, as far as we are aware, the first case of Down's syndrome with atrioventricular septal defect with common atrioventricular junction, common arterial trunk, and severe coarctation of the aorta.

B-type natriuretic peptide as a marker for cardiac dysfunction in anthracycline-treated children.

BACKGROUND: Anthracyclines (AC) are useful antineoplastic agents, whose utility is limited by progressive cardiotoxicity. Our purpose was to evaluate plasma B-type natriuretic peptide (BNP), as a screening test for detecting late cardiac dysfunction in AC-treated children and to determine the prevalence of late cardiac dysfunction at low cumulative AC doses. MATERIALS AND METHODS: This was a prospective study in which patients who had completed AC therapy at least 1 year earlier, underwent a detailed echocardiogram and a simultaneous BNP level. Cardiac dysfunction was defined as any one of the following: shortening fraction (FS) <29%, rate corrected velocity of circumferential fiber shortening (VCFc) <0.9 c x sec(-1), end systolic wall stress (ESWS) >60 g x cm(-2), abnormal VCFc: ESWS ratio or decreased mitral inflow velocity (E/A) ratios, compared to age-specific norms. RESULTS: The cohort (n = 63) included 37 males with a median age of 13.1 years (range, 6.5-26.5 years). Cardiac dysfunction was found in 26 (41%) patients and in 40% of patients who received cumulative doses <150 mg x m(-2). ESWS was the most common abnormality. Mean BNP levels in the subset with abnormal function were significantly higher than the normal group (23.4 +/- 25.3 vs. 14.2 +/- 8.9 pg x ml(-1), P = 0.02). CONCLUSIONS: Plasma BNP was significantly elevated in AC-treated patients with late cardiac dysfunction, although there was considerable overlap of levels between groups with and without cardiac dysfunction. BNP may need further evaluation as a serial index of cardiac function in this population. Cardiac dysfunction was observed in a significant proportion of patients, even at low cumulative AC doses.