The Effect of Cardiac Mass and Venous Return in Children with Postural Orthostatic Tachycardia Syndrome: A Prospective, Observational Study.

Low left ventricular mass index (LVMI) is thought to limit exercise tolerance in adult patients with postural orthostatic tachycardia syndrome (POTS). This finding has not been studied in children. We evaluated the effect of LVMI and hemodynamics at baseline and during exercise in POTS versus controls. POTS and control subjects aged 12-18 years were prospectively enrolled. POTS patients underwent autonomic studies. An echocardiogram was performed on all patients at baseline and during exercise. LVMI, venous return from inferior vena cava (IVC-VTI), left ventricular dimension, and cardiac output were assessed at baseline and during exercise. Generalized linear modeling with mixed effects was used to perform repeated measures testing between POTS and controls. Eighteen POTS patients (14 female, aged 15.4 ± 1.4 years) and nine control subjects (six female, aged 15.0 ± 1.3 years; p = 0.44) were enrolled. At baseline, LVMI was similar in both groups. During exercise, IVC-VTI, left ventricular end-diastolic dimension and volume, and stroke volume were lower in POTS patients. Peak heart rate was higher in POTS patients, but cardiac output was similar in both groups. Exercise time was higher in the control group (11.4 ± 2.7 min vs 9.2 ± 2.1, p = 0.024). Lower venous return resulted in smaller cardiac dimension and stroke volume during exercise. Higher heart rate in POTS may compensate to achieve similar cardiac output compared with control subjects. Lower ventricular filling and earlier time to peak heart rate may explain lower exercise capacity in pediatric POTS.

Computed tomography and magnetic resonance imaging of vascular rings and other things: a pictorial review.

Compression of the airway, esophagus or both by aortic and pulmonary vessels can be caused by a variety of anatomical situations. Vascular rings are the most commonly encountered entity; however, compression can also occur from less common anomalies such as a left pulmonary artery sling or innominate artery compression. Vascular rings and other vascular compression abnormalities can be challenging to visualize and image and often require advanced imaging by CT or MRI to better understand the cause and extent of compression. Atretic vascular structures, such as the ligamentum arteriosum or atretic arch, play a key role in creating a vascular ring and do not enhance with contrast agent in a typical fashion. Despite these imaging challenges, classic and useful signs can indicate the presence or absence of a vascular ring or compression.

Aortic dilatation in children with mild to moderate chronic kidney disease.

BACKGROUND: Children with mild to moderate chronic kidney disease are at an increased risk for cardiovascular sequelae, the leading cause of death in children with end-stage renal disease. We aimed to establish the prevalence of aortic dilatation, a newly recognized cardiovascular sequelae of renal disease, within a cohort of pediatric patients with mild to moderate kidney disease. METHODS: A total of 501 children enrolled in the Chronic Kidney Disease in Children study contributed imaging data between April 2011 and February 2015. Aortic dilatation was defined as a dimension exceeding a z-score of 2 at any of three locations: aortic root, sinotubular junction, or the ascending aorta. RESULTS: At baseline echocardiographic evaluation, 30 (6%) children were identified to have aortic dilatation in at least one of the three locations. Multivariate analysis demonstrated an increased odds ratio for the presence of aortic dilatation associated with the following variables: high diastolic blood pressure z-scores, low weight z-score, and low body mass index z-score. Presense of protein energy wasting (modified definition, OR 2.41, 95%CI 1.23, 4.70) was the strongest independent predictor of aortic dilatation. CONCLUSION: In conclusion, aortic dilatation does occur early in the course of chronic kidney disease and associates with markers of poor nutrition. Future studies should continue to evaluate these risk factors longitudinally as the kidney disease progresses.

Correction to: Aortic dilatation in children with mild to moderate chronic kidney disease.

The original version of this article unfortunately contained a mistake.

MRI detection of occult venous anomalies in a patient with Williams syndrome: a case report.

Williams syndrome is a multisystem, congenital disorder which is commonly associated with arterial stenoses: supravalvar aortic stenosis and peripheral pulmonary artery stenosis. Venous abnormalities have not been previously reported in children with Williams syndrome. We present a case of a 3-year-old girl with Williams syndrome and diffuse venous ectasia as detected by MRI.

Left ventricular outflow tract obstruction: Uptake of familial cardiac screening and parental knowledge from a single tertiary care center.

Left ventricular outflow tract obstruction (LVOTO) malformations exhibit higher heritability than other cardiac lesions and cardiac screening is encouraged for first-degree relatives. This study sought to determine the uptake of familial cardiac screening in families with an infant with an LVOTO and assess parental knowledge regarding genetics and heritability of LVOTO. A chart review of the period 2010-2015 identified 69 families who received genetic counseling regarding a diagnosis of LVOTO in an infant. Surveys assessing familial cardiac screening and parental knowledge were completed by a parent in 24 families (completion rate of 35%). Forty percent (36/89) of all at-risk first-degree family members completed cardiac screening. The presence of additional congenital malformations in the affected infant was the only significant factor reducing the uptake of familial cardiac screening (p = 0.003). The reported uptake of screening for subsequent at-risk pregnancies was 11/12 (92%) compared to 25/77 (32%) of living at-risk relatives. Survey respondents answered seven knowledge questions with an average score of 5.2 and all correctly identified that LVOTO can run in families. Uptake of familial cardiac screening is occurring in less than half of at-risk individuals, despite parents demonstrating basic knowledge and receiving genetic counseling. Follow-up counseling in the outpatient setting to review familial screening recommendations should be considered to increase uptake and optimize outcomes.

Cystatin C and Cardiac Measures in Children and Adolescents With CKD.

BACKGROUND: Cardiovascular disease (CVD) is highly prevalent among children with chronic kidney disease (CKD). Cystatin C is an established marker of kidney function and an emerging biomarker for CVD events. We quantified the relationship between cystatin C level and cardiac structure and function over time among children with CKD and assessed whether cystatin C level and diastolic function retained an association after accounting for kidney function. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 678 children and adolescents with mild to moderate CKD enrolled in the CKD in Children (CKiD) Study with 1,228 echocardiographically obtained cardiac structure and function measurements. PREDICTOR: Serum cystatin C (mg/L) measured annually. OUTCOMES: Cardiac structure (left ventricular mass index [g/m2.7]) and cardiac function (shortening fraction; E/A, E'/A', E/E' ratios) measured every other year. MEASUREMENTS: Demographics and anthropometrics, measured glomerular filtration rate (mGFR), heart rate, blood pressure, hemoglobin z score, serum albumin level, and calcium-phosphorus product. RESULTS: Independent of time, each 1-mg/L increase in cystatin C level was independently associated with a concurrent 7.7% (95% CI, 5.3%-10.0%) increase in left ventricular mass index, a -4.7% (95% CI, -7.0% to -2.4%) change in E/A ratio, a -6.6% (95% CI, -9.0% to -4.2%) change in E'/A' ratio, and a 2.5% (95% CI, 0.3%-4.7%) increase in E/E' ratio. mGFR was also independently associated with E'/A' ratio. When cystatin C level and mGFR were included in the same model, cystatin C level remained independently associated with E'/A' ratio, whereas mGFR was not. LIMITATIONS: 24% of the cohort was missing data for outcomes of interest or measurements; study population includes only children and adolescents with mild to moderate CKD. CONCLUSIONS: In this study of children and adolescents with mild to moderate CKD, cystatin C level was independently associated with cardiac structure and diastolic function. Cystatin C level remained able to predict diastolic function decline via E'/A' ratio even after adjusting for mGFR, suggesting that cystatin C level may have an independent role in CVD risk stratification among children and adolescents with CKD.

Utility of Echocardiography in the Assessment of Left Ventricular Diastolic Function and Restrictive Physiology in Children and Young Adults with Restrictive Cardiomyopathy: A Comparative Echocardiography-Catheterization Study.

The aim of the study is to determine the utility of echocardiography in the assessment of diastolic function in children and young adults with restrictive cardiomyopathy (RCM). RCM is a rare disease with high mortality requiring frequent surveillance. Accurate, noninvasive echocardiographic measures of diastolic function may reduce the need for invasive catheterization. Single-center, prospective, observational study of pediatric and young adult RCM patients undergoing assessment of diastolic parameters by simultaneous transthoracic echocardiogram (TTE) and invasive catheterization. Twenty-one studies in 15 subjects [median (IQR) = 13.8 years (7.0-19.2), 60% female] were acquired with median left ventricular end-diastolic pressure (LVEDP) 21 (IQR 18-25) mmHg. TTE parameters of diastolic function, including pulmonary vein A wave duration (r s  = 0.79) and indexed left atrial volume (r s  = 0.49), demonstrated significant positive correlation, while mitral valve A (r s  = -0.44), lateral e' (r s  = -0.61) and lateral a' (r s  = -0.61) velocities showed significant negative correlation with LVEDP. Lateral a' velocity (≤0.042 m/s) and pulmonary vein A wave duration (≥156 m/s) both had sensitivity and specificity ≥80% for LVEDP ≥ 20 mmHg. In pediatric and young adult patients with RCM, lateral a' velocity and pulmonary vein A wave duration predicted elevated LVEDP with high sensitivity and specificity; however, due to technical limitations the latter was reliably measured in 12/21 patients. These noninvasive parameters may have utility in identifying patients that require further assessment with invasive testing. These findings require validation in a multicenter prospective cohort prior to widespread clinical implementation.

The use of a Berlin Heart EXCOR LVAD in a child receiving chemotherapy for Castleman's disease.

We present the unique case of a pediatric patient who received chemotherapy for a diagnosis of CD, while mechanically supported with a Berlin EXCOR LVAD secondary to restrictive cardiomyopathy. A four-yr-old previously healthy male with restrictive cardiomyopathy required MCS after cardiac arrest but was diagnosed with multicentric CD, a non-malignant lymphoproliferative disorder fueled by excessive IL-6 production. Treatment with IL-6 blockade (tocilizumab) every two wk and methylprednisolone had no effect on his lymph nodes or cardiac function while on temporary RotaFlow. A Berlin LVAD was placed for treatment with rituximab, COP, vincristine, and methylprednisolone. After three courses of chemotherapy, his inflammatory markers normalized and his lymphadenopathy decreased but cardiac function remained severely depressed. He tolerated chemotherapy on the Berlin but required frequent titrations of his anti-coagulation regimen and he did suffer a hemorrhagic stroke. His clinical status improved significantly with rehabilitation, and he tolerated heart transplantation without further complications. MCS is a feasible option as a bridge to recovery or heart transplant eligibility for patients with hemodynamic collapse requiring chemotherapy but it does necessitate close titration of the anti-coagulation regimen to coincide with changes in the inflammatory state.

Prevalence and predictors of aortic dilation as a novel cardiovascular complication in children with end-stage renal disease.

BACKGROUND: Cardiovascular disease is the leading cause of death in children with end-stage renal disease (ESRD). Isolated aortic dilation (AD) is rare in children. We aimed to determine the prevalence and the risk factors for AD in children with ESRD. METHODS AND STUDY DESIGN: We reviewed records of all ESRD patients followed mat our institution from January 2007 to October 2012. AD was defined as Z-score > 2 in the dimension of at least one of the following echocardiographic aortic parameters: annulus, root at the sinus, sino-tubular junction, or ascending aorta. RESULTS: The records of 78 patients on dialysis and 19 kidney transplant recipients were available. 30 patients (30.9%) had AD. Multivariate analysis revealed independent associations of AD with body mass index (BMI) Z-score (OR = 0.52, 95% confidence interval (CI): 0.35 - 0.78) and ESRD secondary to glomerular disease (OR = 4.58, 95% CI: 1.45 - 14.46). We developed a classification and regression tree (CART) model to identify patients at low vs. high AD risk. Our model classified 62 patients of the cohort (64%) to be high- or lowrisk, with a positive predictive value of 89% and a negative predictive value of 100%. CONCLUSION: Our data suggest that AD, as a possible marker of aortopathy and early aneurysm formation, is a novel and prevalent cardiovascular complication in ESRD children. Glomerular disease and low BMI Zscore appear to be potent predictors. CART modeling helps identify high-risk children, potentially guiding decisions regarding targeted echocardiographic evaluations.

Comparison of area-length method by echocardiography versus full-volume quantification by cardiac magnetic resonance imaging for the assessment of left atrial volumes in children, adolescents, and young adults.

Left atrial (LA) size is a known predictor of adverse cardiovascular events. Echocardiography is the modality of choice for the evaluation of atrial size; however, cardiac magnetic resonance imaging (cMRI) remains the "gold standard." We sought to calculate atrial volumes using the area-length method by both echocardiography and cMRI and compare them with area-volume quantification by cMRI. Thiry-eight patients (mean age 20 ± 12 years, 71% male) who underwent cMRI and echocardiography between September 2010 and June 2012 were retrospectively identified. The time interval between the two studies was ≤ 6 months. LA volumes by echocardiogram were estimated using the area-length method: LA volume = (0.85 × area(4ch) × area(2ch))/(shortest atrial length). The atrial length and area were measured in standard apical two-chamber and four-chamber planes. Measured values were indexed to body surface area (BSA). CMRI measurements were obtained from prospectively gated steady-state free precession cine stack images obtained in a standard four-chamber plane. LA volumes were calculated using Simpson's method: LA volume = LA area × (slice thickness + gap) per slice. Slice thickness ranged from 5 to 7 mm with contiguous slices of 5 to 7 mm. The values were indexed to BSA. Statistics were summarized using measures of central tendency. LA volumes by echocardiography were significantly less than those by full-volume cMRI quantification. The mean LA volume by echocardiography and full-volume cMRI were 35 ± 14.5 and 42.4 ± 17.2, respectively (p = 0.05). The mean difference between LA volumes obtained by the two methods was 7.4 ± 10.6. LA volume measured by cMRI using the area-length method closely approximated full-volume assessment by cMRI with mean values of 42.9 ± 17.4 versus 42.4 ± 17.2, respectively (p = 0.91). There were no significant differences in the patient characteristics between the two study modalities. LA volumes as measured by echocardiography using the area-length method consistently underestimated the true volume when compared with cMRI. LA volumes measured using the area-length method by cMRI is an alternative technique for accurately quantifying chamber size and can be useful in decreasing scan time or when full-volume data sets are incomplete.

Predictors of exaggerated exercise-induced systolic blood pressures in young patients after coarctation repair.

BACKGROUND: In normotensive subjects, an exaggerated blood pressure response to exercise is associated with the development of resting hypertension. We sought to determine the prevalence of elevated blood pressures during exercise in post-operative coarctation patients with normal resting blood pressure, and investigate associations with exercise-induced hypertension in this population. METHODS: A total of 38 patients were enrolled after end-to-end anastomosis repair and resting normotension. All patients underwent anthropometric and blood pressure measurements, echocardiographic evaluation of function, arterial stiffness assessment by pulse wave velocity, and a graded exercise test. An abnormal response was defined as a maximum systolic blood pressure greater than the 95th percentile of published normal values. Correlation analyses and stepwise regression analyses were performed. RESULTS: The mean age was 12.7 years, including 79% male patients. The mean resting systolic blood pressure was 111.3 millimetres of mercury and the mean exercise systolic blood pressure was 178.1 millimetres of mercury. The prevalence of a systolic blood pressure greater than the 95th percentile was 16.7%. In multivariate analysis, the exercise systolic blood pressure index was associated with body mass index, age, aortic valve annulus, shortening fraction, and pulse wave velocity (R2 equal to 0.79, p equal to 0.0009). Estimates of ventricular filling and indexed left ventricular mass were elevated. CONCLUSIONS: There is a risk of elevated systolic blood pressure during exercise in normotensive patients after coarctation repair. Resting blood pressures are useful but not sufficient. Echocardiography demonstrated abnormalities suggestive of a chronic cardiac burden despite resting normotension. Regular imaging may be necessary to improve long-term outcomes. New paradigms for the continued follow-up of these patients are necessary.

Tetralogy of Fallot Associated With Right Aortic Arch and Isolated Left Brachiocephalic Artery.

A newborn presented with tetralogy of Fallot (TOF), right aortic arch (RAA), and isolated left brachiocephalic artery. The RAA supplied the right common carotid artery, right vertebral artery, and right subclavian artery, in that order. The left common carotid and left subclavian arteries were in continuity with no aortic origin. Ultrasound demonstrated retrograde flow in the left vertebral artery supplying antegrade flow to the diminutive left subclavian artery (ie, "steal phenomenon"). The patient underwent repair of TOF without intervention on the left common carotid or left subclavian arteries and is being followed conservatively.

Innominate Artery Compression Syndrome.

Vascular mediated airway compromise is a fairly common clinical scenario. The diagnosis of innominate artery compression may be challenging due to lack of standardized imaging criteria for diagnosis or for surgical intervention.

Abnormal Maximal and Submaximal Cardiopulmonary Exercise Capacity in Pediatric Stem Cell Transplant Recipients Despite Normal Standard Echocardiographic Parameters: A Pilot Study.

Left ventricular systolic dysfunction is a known complication of stem cell transplantation (SCT). There has been minimal research to determine whether subclinical cardiac dysfunction exists in SCT patients using tools other than standard echocardiography, such as maximal and submaximal effort cardiopulmonary exercise testing (CPET) and vascular function studies. The objective of this study was to determine the rate of subclinical cardiac dysfunction in patients with normal ejection fraction after SCT, identified by abnormal values by CPET, tissue-Doppler imaging, and arterial stiffness measurements and to further describe submaximal exercise test measures in this population. A prospective cohort study of SCT survivors who were at least 3 years after SCT without prior anthracycline or radiation exposure and with preserved systolic function (left ventricular ejection fraction > 50%) was performed to evaluate for abnormalities in exercise, vascular function, and diastolic function in an effort to detect subclinical dysfunction in SCT patients. Eleven patients (12.4 ± 3.8 years old) were included in the study. No patients had diastolic dysfunction. All patients completed a maximal effort exercise test, and 73% (8/11) had abnormal peak oxygen consumption (Vo2 peak), which is a measure of aerobic fitness. However, during submaximal effort CPET, 45% (5/11) had an abnormal Vo2 at anaerobic threshold (i.e., the point in exercise where aerobic transitions to anaerobic metabolism and fatigue starts), and 64% (7/11) had an abnormal oxygen uptake efficiency slope (a measure that relates Vo2 peak to total ventilation). Eighty-six percent (6/7) of the patients with an abnormal oxygen uptake efficiency slope ultimately had an abnormal Vo2 peak. There were no vascular function abnormalities. Pediatric survivors of SCT often have abnormal maximal and submaximal exercise capacity without vascular or cardiac dysfunction.

Establishment of Specialized Clinical Cardiovascular Genetics Programs: Recognizing the Need and Meeting Standards: A Scientific Statement From the American Heart Association.

Cardiovascular genetics is a rapidly evolving subspecialty within cardiovascular medicine, and its growth is attributed to advances in genome sequencing and genetic testing and the expanding understanding of the genetic basis of multiple cardiac conditions, including arrhythmias (channelopathies), heart failure (cardiomyopathies), lipid disorders, cardiac complications of neuromuscular conditions, and vascular disease, including aortopathies. There have also been great advances in clinical diagnostic methods, as well as in therapies to ameliorate symptoms, slow progression of disease, and mitigate the risk of adverse outcomes. Emerging challenges include interpretation of genetic test results and the evaluation, counseling, and management of genetically at-risk family members who have inherited pathogenic variants but do not yet manifest disease. With these advances and challenges, there is a need for specialized programs combining both cardiovascular medicine and genetics expertise. The integration of clinical cardiovascular findings, including those obtained from physical examination, imaging, and functional assessment, with genetic information allows for improved diagnosis, prognostication, and cascade family testing to identify and to manage risk, and in some cases to provide genotype-specific therapy. This emerging subspecialty may ultimately require a new cardiovascular subspecialist, the genetic cardiologist, equipped with these combined skills, to permit interpretation of genetic variation within the context of phenotype and to extend the utility of genetic testing. This scientific statement outlines current best practices for delivering cardiovascular genetic evaluation and care in both the pediatric and the adult settings, with a focus on team member expertise and conditions that most benefit from genetic evaluation.

Comparison of Native T1, Strain, and Traditional Measures of Cardiovascular Structure and Function by Cardiac Magnetic Resonance Imaging in Patients With Anderson-Fabry Disease.

Cardiovascular magnetic resonance imaging (CMR) has emerged as a powerful tool to illuminate cardiovascular pathology in Anderson-Fabry disease (AFD); however, further study is required to develop clinically useful monitoring paradigms. The objective of this study was to retrospectively evaluate strain, native septal T1 values, and standard CMR measurements in a cohort of AFD patients to characterize useful measures of cardiovascular dysfunction that may be derived from a CMR platform. Eighteen patients were identified (n = 8 males) and divided according to presence or absence of left ventricular hypertrophy (LVH). Biometric data were gathered and native T1 and strain values were measured for all patients. Patients with LVH were older and had significantly lower native T1 measured at the apical septal (893 ± 78 vs 1044 ± 217 ms, p = 0.035), midventricular septal (864 ± 76 vs 988 ± 67 ms, p = 0.016), and basal septal (867 ± 58 vs 1027 ± 84 ms, p = 0.006) regions. Circumferential strain was more positive in patients with LVH (-13.5% ± 5.0% vs -18.7% ± 2.7%, p = 0.042), but longitudinal strain was not significantly different between groups. Patients with LVH had higher stroke volumes (114.5 ± 9.7 vs 96.7 ± 17.8 ml, p = 0.050), but other standard CMR measures were not significantly different. In conclusion, AFD patients with LVH have reduced native T1 and more positive circumferential strain compared to those without. The basal septum may be an appropriate region for standard measure of native T1 in this population.

Arrhythmia and Clinical Cardiac Findings in Children With Anderson-Fabry Disease.

Anderson-Fabry Disease (AFD) is a lysosomal storage disorder that results in progressive cardiovascular hypertrophy, scarring, and arrhythmia burden; yet, the early cardiac phenotype of AFD is still poorly defined. To further characterize early cardiac features in AFD, we evaluated electrocardiographic and clinical findings contained in a local cohort of pediatric AFD patients and arrhythmia data in children enrolled in the Fabry Registry. Twenty-six local patients aged <18 years were identified (average age 9.7 ± 3.8 years, n = 12 males). Sinus bradycardia was the most frequent rhythm abnormality (23%), followed by ectopic atrial rhythm (12%) and premature atrial contractions (8%). No PR, QRS, or QTc intervals were prolonged. First-degree atrioventricular block developed in 1 female during follow-up. Chest pain (35%) and palpitations (23%) were highly prevalent complaints in clinical follow-up and did not differ significantly between genders. Structural findings included aortic root dilation in 3 patients and concurrent aortic insufficiency in 1. Among 593 patients aged < 18 years with electrocardiographic data identified in the Fabry Registry, sinus bradycardia, defined as heart rate <60 beats per minute per registry guidelines, was the most common arrhythmia (12.3%). In conclusion, clinical findings and subtle abnormalities of conduction, rhythm, and structure point toward a heterogeneous inception of Fabry cardiomyopathy. Bradycardia, common in adults, is frequent even among children with AFD. Given the potential for early initiation of enzyme replacement therapy to reduce cardiovascular morbidity, continued work to develop paradigms of therapy and longitudinal cardiovascular surveillance is warranted.