Irene D. Lytrivi

Relation of Coarctation of the Aorta to the Occurrence of Ascending Aortic Dilation in Children and Young Adults With Bicuspid Aortic Valves

Children with bicuspid aortic valve (BAV) have aortic dilation that is present and progressive from birth irrespective of the functional state of the valve. There are no published data comparing aortic dilation in children with BAV with and without aortic coarctation (CoA). The objectives of this study were to (1) compare differences in aortic dimensions and rates of dilation between children with isolated BAV with those of children with BAV and CoA and (2) identify risk factors for the development of aortic dilation. Patients with BAV with CoA (group A) and without CoA (group B) were identified from our echocardiographic database (1993 to 2006). Aortic measurements at 4 levels were obtained, and z scores were compared. Criteria for exclusion were severe aortic regurgitation/stenosis, previous aortic valvuloplasty, complex left-sided cardiac disease, ventricular septal defects, and Turner, Noonan, Williams, and Marfan syndromes. There were 600 echocardiograms in 247 patients. Group A had 192 echocardiograms in 53 patients (median age 11.3 years; range 0 to 30; median follow-up 7 years), and group B had 382 in 194 patients (median age 8.7 years; range 0 to 29; median follow-up 4 years). Group B had significantly greater ascending aorta dimensions (p<0.05) and significantly faster rates of aortic dilation (p<0.0001). The ascending aorta in patients with BAV and CoA did not dilate to the same degree as in patients with isolated BAV. In conclusion, valve morphologic characteristics and function and age at CoA repair had none to minimal impact on aortic dimensions.

Frequency of Aberrant Subclavian Artery, Arch Laterality, and Associated Intracardiac Anomalies Detected by Echocardiography

Tetralogy of Fallot is generally considered to be the most common congenital heart defect associated with an aberrant subclavian artery (ASA), but the prevalence of ASA in patients with other cardiac anomalies is not well described. The pediatric echocardiography database, with 15,871 initial echocardiograms, was searched for all patients with ASA. Arch laterality and associated intracardiac anomalies were documented for each patient. ASA was found in 226 patients, of whom 171 had a left aortic arch (LAA) and 55 had a right aortic arch (RAA). The occurrence of ASA was 1% in patients with LAA (171 of 15,650) and 25% in patients with RAA (55 of 221; p = 0.001). Intracardiac anatomy was normal in 32% of patients with ASA/LAA and 25% with ASA/RAA. Conotruncal anomalies occurred more frequently with ASA/RAA than ASA/LAA (36% vs 18%; p = 0.01). Atrioventricular canal defects accounted for 10% and left-sided cardiac obstructive lesions accounted for 11% of subjects with ASA/LAA. ASA was rarely associated with d-transposition of the great arteries (1 of 226) and double-outlet right ventricle (5 of 226). The prevalence of ASA was highest in patients with interrupted aortic arch (11 of 38; 29%). In patients with tetralogy of Fallot, the overall prevalence of ASA was 8% (34 of 447), but was higher with RAA (16 of 103; 16%). The highest prevalence of ASA occurred in the subgroup of patients with tetralogy of Fallot with pulmonary atresia and RAA (6 of 25; 24%). In conclusion, ASA was more common in patients with RAA, especially with conotruncal anomalies. In patients with LAA, hypoplastic left heart syndrome, aortic coarctation, and atrioventricular canal defects were commonly associated with ASA.

Imaging of congenital coronary artery anomalies

Imaging of the coronary arteries is an important part of the evaluation of children with congenital heart disease and isolated congenital coronary artery anomalies. Echocardiography remains the main imaging modality and is complemented by MRI and CT angiography in the older or difficult-to-image child. We review echocardiography, MRI, and CT angiography for coronary artery imaging, with emphasis on techniques. The clinical implications of isolated congenital coronary artery anomalies are also addressed, along with a discussion about the current consensus on optimal management of these anomalies.

Normal Values of Left Atrial Volume in Pediatric Age Group Using a Validated Allometric Model

Background—Left atrial volume (LAV) increase is an indicator of diastolic dysfunction and a surrogate marker of significant left to right shunts. Normalization of LAV is currently performed by indexing to body surface area1 (BSA1). The indexed LAV thus derived does not account for the nonlinear relationship of physiologic variables to BSA and has not been tested for independence to body size. Our objective was to identify a valid allometric model for indexing LAV and use it to develop Z-scores in children. Methods and Results—LAV was measured in 300 normal subjects by echocardiography using the biplane area length method. LAV/BSA1 had a residual relationship to BSA (r=0.52, P<0.0001). The allometric exponent (AE) derived for the entire cohort (1.27) using the least squares regression analysis also failed to eliminate the residual relationship to BSA (r=−0.15, P=0.01). Dividing the cohort in two groups with a BSA cut-off of 1 m2 provided the best-fit allometric model. The AE for each group was 1.48 and 1.08 for BSA⩽1 m2 and >1 m2, respectively, and was validated against an independent sample. The mean indexed LAV±SD for BSA⩽1 m2 and >1 m2 is 31.5±5.5 mL and 26.0±4.2 mL, respectively, and was used to derive Z-scores. Conclusions—This study demonstrates the fallacy of using “per-BSA1 standards” for normalization of LAV in pediatrics. LAV/BSA1.48 for children with BSA⩽1 m2 and LAV/BSA1.08 for those with BSA>1 m2 is accurate and can be used to derive Z-scores.

Regression of left ventricular hypertrophy in children with antihypertensive therapy

Left ventricular hypertrophy (LVH) is a complication of hypertension that has received great attention in the adult population. Large-scale randomized control studies in adults have demonstrated that LVH regresses in response to pharmacologic intervention. While it is known that LVH occurs as a complication of hypertension in the pediatric population, few studies have focused on its regression with pharmacological intervention. We report on three cases of hypertension-induced LVH in the pediatric population and its regression after treatment with antihypertensive medications. This report brings to light the need for larger, prospective studies on the incidence, natural history, and treatment of LVH associated with hypertension in the pediatric population.

Acute Myopericarditis After Multiple Vaccinations in an Adolescent: Case Report and Review of the Literature

We report a case of postvaccination acute myopericarditis in an adolescent. The patient presented with acute chest pain, diffuse ST-segment elevation, and elevated cardiac enzyme levels. Cardiac MRI was consistent with acute myocarditis. He recovered within a few days with nonsteroidal antiinflammatory treatment and remains clinically stable, with improvement of MRI findings at the 10-week follow-up. Postvaccination cases of myopericarditis reported in the pediatric literature are also reviewed.

Electrocardiographic Predictors of Left Ventricular Hypertrophy in Pediatric Hypertension

OBJECTIVE To determine the efficacy of electrocardiography (ECG) in detecting left ventricular hypertrophy (LVH) in pediatric hypertension (HT). STUDY DESIGN Concomitant echocardiograms and electrocardiograms in 108 children with HT were reviewed. Left ventricular mass (LVM), assessed by echocardiography, was used as a basis for a diagnosis of LVH (echo LVH) using accepted pediatric criteria. Using Wilcoxons rank-sum test, 14 ECG variables were compared between subjects with and without echo LVH. Spearman correlations were used to examine the linear association between echo LVH and these ECG variables. The sensitivity and specificity of ECG in diagnosing LVH were computed. RESULTS Of the 108 subjects studied, 35 (32%) met the pediatric criteria for LVH; of these, 8 (7.4%) also met the adult criteria (>51 g/m(2.7)) for LVH. Mean values for only 5 ECG criteria differed significantly among the groups: RI, SaVR, RaVL, RI+SIII, and SVI+RV6 (P < .05). Significant correlations were found for several ECG criteria and at least 1 measure of LVM, but the magnitudes were modest. Standard ECG criteria predicted LVH with high specificity (>90%) but low sensitivity (<35%). RI >10 mm was identified as demonstrating a modestly improved positive likelihood ratio of approximately 3. CONCLUSIONS ECG is not an adequate predictor of LVH for clinical use in HT.

The Accuracy of Echocardiographic Assessment of Left Ventricular Size in Children by the 5/6 Area × Length (Bullet) Method

Introduction: Left ventricular end‐diastolic volume (LVEDV) calculation is important in decision making in children with congenital heart disease (CHD). This study examined the accuracy of LVEDV calculation by the formula: 5/6 × area × length (“bullet” method), by comparing echocardiographic (ECHO) LVEDV against cardiac magnetic resonance (CMR). Methods: ECHO and CMR data from 72 consecutive subjects with CHD ≤10 years of age were retrospectively reviewed. Exclusion criteria included: >3 months between examinations; unavailable or poor‐quality images. Subxiphoid short‐ and long‐axis echocardiographic images were analyzed. Bullet LVEDV was compared to CMR volumes. Results: Seventeen subjects (median age 5.5 years, range 1–10 years) comprised the study group. ECHO and CMR LVEDV showed an excellent correlation (r = 0.97) and a good agreement with a mean difference (limits of agreement) of −1.0 mL (−13.9 to 11.9 mL). Conclusions: Subxiphoid echocardiographic bullet method of measuring LVEDV shows a good agreement with CMR obtained LV size in young children. (Echocardiography 2010;27:691‐695)

Prognostic Value of Exercise Testing During Heart Transplant Evaluation in Children

Background—Maximum oxygen consumption (peak VO2) <50% predicted on exercise testing is a class I indication for heart transplant (HT) listing in children. This recommendation is based on exercise data in adults. We assessed the association of peak VO2<50% predicted during HT evaluation with freedom from death or deterioration in children. Methods and Results—We analyzed all children who underwent exercise testing during HT evaluation at our center between 2002 and 2011. Patients with peak VO2<50% predicted were compared with those with peak VO2≥50% predicted for the composite outcome of death before HT, initiation of mechanical circulatory support, and HT at highest urgency status, using time-to-event analyses. There were 50 children in the study (median age, 15 years; interquartile range, 13–17 years; 24 girls; 18 with palliated single ventricle). Overall, 24 children reached the composite end point. Peak VO2<50% predicted was associated with outcome in children with biventricular circulation (hazard ratio, 4.7; 95% confidence interval, 1.8–12.3; P<0.001) but not in those with a palliated single ventricle (hazard ratio, 1.3; 95% confidence interval, 0.1–12.0; P=0.80). Similarly, VE/VCO2 slope ≥34 was associated with outcome in children with biventricular circulation (hazard ratio, 2.7; 95% confidence interval, 1.1–7.1; P<0.001) but not in children with a palliated single ventricle. Conclusions—Exercise testing during HT evaluation in children with biventricular circulation identified those at higher risk of death or deterioration in this small study. Larger studies are needed to assess the role of exercise testing during HT evaluation in children with a palliated single ventricle.

Donor predictors of allograft utilization for pediatric heart transplantation

Pediatric heart transplantations are limited by the supply of donor allografts. We sought to determine the cardiac allograft utilization rate for pediatric donors and identify donor factors that predict graft use for transplantation. The United Network for Organ Sharing deceased donor database was queried from April 30, 2006, to March 31, 2014. Donor risk factors that might affect graft use for cardiac transplantation were evaluated. The pediatric cardiac graft utilization rate was calculated, and logistic regression modeling was performed to determine the relationship of risk factors with graft use for transplantation. During the study period, 6682 eligible cardiac donors <18 years of age were identified, and 3758 (56.2%) grafts were utilized for transplantation. Grafts from male donors (OR 1.181) were significantly associated with graft utilization. Graft donor age >1 year (OR 0.363), non‐O blood type (OR 0.586), CDC ‘high‐risk’ donor status (OR 0.676), use of inotropes (OR 0.718), use of >2 inotropes (OR 0.328), and donor left ventricular ejection fraction <50% (OR 0.045) were significantly associated with graft nonutilization. The pediatric cardiac allograft utilization rate and risk factors for graft use for transplantation have been identified. Additional studies will be needed to assess the donor–recipient relationship on pediatric transplant outcomes.