J.E. Potts

Kawasaki Disease in the Older Child

Objectives.u2003To determine the prevalence of Kawasaki disease in older children and to evaluate its clinical presentation, time to diagnosis, and outcome in comparison with younger patients with the disease. Methodology.u2003A retrospective analysis of all patients discharged with a diagnosis of Kawasaki disease at a pediatric tertiary care hospital over a 12-year period. Results.u2003A total of 133 patients were included in this study; 7.5% were 9 years of age or older at the time of illness. Patients were grouped by age: infants included children age 1 to 8 years of age and children 9 years of age or older. Older children had a higher frequency of abnormal cardiovascular physical examination (50%) versus children (6%) and infants (10%). The older age group and the infants had a higher prevalence of coronary artery abnormalities and poor left ventricular function than did the 1- to 8-year-olds. Eighty percent of the older children had coronary arteries that were either dilated or aneurysmal, and 30% demonstrated left ventricular dysfunction on initial echocardiography. The number of days to diagnosis after meeting the diagnostic criteria was 5.8 ± 2.3 for infants, 5.2 ± 1.5 for older children, and 1.9 ± 0.3 for children. Older children had a complicated course of Kawasaki disease compared with younger patients. Conclusion.u2003We found a higher prevalence of older children with Kawasaki disease at our center than has previously been reported. Older patients, as well as infants, had a higher rate of coronary artery abnormalities than did the children between 1 and 8 years of age. Older age at the time of illness or a delay in treatment may be important factors in determining cardiac involvement in Kawasaki disease.

Medications Used to Manage Supraventricular Tachycardia in the Infant A North American Survey

Supraventricular tachycardia is the most common pediatric arrhythmia, but there is no consensus and little evidence to guide its treatment. We sent a questionnaire to pediatric cardiologists in North America to assess the current practice pattern. Of 1534 surveys mailed, 352 (23%) were returned and 295 (19%) had complete data for analysis. In the acute setting, 11 different medications were chosen. The most commonly used in the infant without preexcitation were digoxin (42%), procainamide (21%), esmolol (13%), propranolol (10%), and amiodarone (8%). In the infant with preexcitation, propranolol (34%), procainamide (23%), esmolol (17%), amiodarone (11%), and digoxin (6%) were used. In the chronic setting, 8 different medications were chosen. The most commonly used in this scenario were digoxin (52%), propranolol (33%), amiodarone (4%), and sotalol (3%). In the infant with preexcitation, propranolol (70%), amiodarone (6%), digoxin (6%), atenolol (6%), and flecainide (5%) were used. Medication choices were influenced by additional electrophysiology training and preexcitation. Digoxin was used less in the setting of preexcitation. There are no comparative trials to explain the different medication choices. Although a number of medications may be efficacious, a randomized clinical trial is needed to offer further guidance.

Myocardial Contractility in Premature Neonates With and Without Patent Ductus Arteriosus

Controversy exists as to whether a hemodynamically significant left-to-right shunt due to a patent ductus arteriosus (PDA) affects ventricular contractility. Load-dependent indices such as ejection fraction and shortening fraction have traditionally been used to assess contractility, but the relationship between the rate-corrected velocity of fiber shortening (MVCFc) and wall stress may be more suitable, as it is a preload-independent, afterload-adjusted method of assessing ventricular contractility. Age-related differences have been established for these variables in normal adults and children and it has been recommended for use in the premature neonate. The study was performed to assess left ventricular contractility in premature neonates with a significant left-to-right shunt due to a PDA. Using echocardiography, we measured the relationship of MVCFc to stress at peak systole (SPS) in two groups of premature infants. Group 1 consisted of 15 controls (680–1495 g, 25–32 weeks’ gestation), and Group 2 of 15 neonates with hemodynamically significant PDA (840–1635 g, 26–33 weeks’ gestation). In both groups, MVCFc was linearly and inversely related to SPS (p < 0.001). The regression equations were as follows: Group 1, MVCFc = −0.0153SPS + 1.70 (R2 = 0.68); and Group 2, MVCF = − 0.019SPS + 1.89 (R2 = 0.76). There was no significant difference in the relationship between the two groups, but their slopes were significantly steeper and had a higher Y-intercept than the relationship we previously reported for older children. This preliminary study establishes the normal MVCFc/SPS relationship in the premature neonate (25–33 weeks’ gestation) and suggests that premature infants function at a higher resting contractile state than older children. A hemodynamically significant PDA has no effect on contractility. These data will be useful in assessing left ventricular contractility in premature neonates with other types of ventricular loading and noncardiac stress.

Could we still improve early and interim outcome after prosthetic systemic-pulmonary shunt? A risk factors analysis

OBJECTIVEnTo identify factors associated with in-hospital and interim mortality in children with a systemic-to-pulmonary shunt (SPS).nnnMETHODSnBetween January 1988 and April 2005, 226 children with a median age of 17 days, and weight of 3.4 kg, underwent an isolated SPS for pulmonary atresia (PA)-VSD/ tetralogy (n=124, 54.9%), functional single ventricle PA (n=35, 5.5%), PA-intact septum (IS, n=31, 13.7%), transposition of the great arteries VSD-PA (n=30, 13.3%), and double outlet right ventricle-PA (n=6, 2.6%). Surgery was performed through sternotomy (group S, n=46) or thoracotomy (group T, n=180). The origin of the SPS was either the innominate artery (n=38) or ascending aorta (n=8) in group S, and the subclavian artery (n=180) in group T.nnnRESULTSnIn-hospital mortality was 5.7%. Univariate and logistic regression analysis revealed younger age (p=0.01), lower body weight (p<0.04), a diagnosis of PA-IS with severe right ventricle hypoplasia (p=0.005), preoperative intubation (p=0.03), increased length of intubation (p<0.0001), longer ICU stay (p<0.0001), and group S (p=0.03) as risk factors for in-hospital death. Group S had a longer median ventilation time (112 vs 30 h, p<0.0001) despite the similar median age, weight, mean indexed shunt size (1.19 vs 1.15 mm/kg, p=0.2), and the number of patients with antegrade pulmonary flow. Interim mortality was 7% (n=15), and younger age (p=0.03), and group T (p=0.03) were independent risk factors for death prior to second-stage surgery. Absence of antiplatelet agents or anticoagulants was not a risk factor for interim mortality.nnnCONCLUSIONSnIn-hospital mortality and longer ventilation time after SPS by sternotomy may be related to pulmonary over circulation due to shunt insertion origin and/or size, and pathologic features. Early and interim outcomes can be improved by using a smaller shunt or changing the SPS insertion origin when using a sternotomy approach.

Anthracycline induced cardiac toxicity in pediatric Ewing sarcoma: a longitudinal study.

Reports on incidence and factors associated with anthracycline cardiotoxicity in patients with Ewing sarcoma vary and few studies evaluate effect over time. Longitudinal trends in cardiac function and prognostic value of % decline in ejection fraction (EF) during therapy have not been previously described in Ewing sarcoma.

Balloon Angioplasty of Right Ventricular Outflow Tract Conduits

Abstract. Palliation of complex congenital heart disease, requiring reconstruction of the right ventricular outflow tract (RVOT), is standard practice. Survival of the homograft is a limiting factor. We examined the role of balloon angioplasty (BAP) in prolonging conduit life. Twelve patients underwent 15 BAP procedures between February 1989 and October 1997. The median age at conduit insertion was 28 months with detection of a significant echo gradient 42 months later. Calcification of homografts, with attendant obstruction and valve dysfunction, was present in all patients. BAP was performed within 1 month of echocardiography and reduced the gradient from a median of 57 to 38 mmHg (p < 0.0005). Echocardiographic follow-up showed persistent gradients (median 68 mmHg) and 11/12 patients went on to conduit replacement after BAP. Only one patient had replacement deferred as a result of BAP. Complications requiring intervention occurred in 20% of the procedures and included bleeding and an unusual balloon fracture. Although BAP can reduce the pressure gradient across the RVOT conduit, the effect is transient and the delay of surgery is not due to improved hemodynamic function. Approximately 10% of cases will benefit from BAP alone, but given the high rate of complications, we do not recommend this procedure as a means of prolonging conduit life.

Exercise and the Multidisciplinary Holistic Approach to Adolescent Dysautonomia.

To determine whether an eight‐week strength training programme as part of a multidisciplinary approach would minimise symptoms and improve quality of life in patients with dysautonomia.

Response Letter to ‘Optimising physiology for adolescents with dysautonomia’

Sir, We would like to thank Dr Thaxter Nesbeth (1) for her interest and insightful comments on our paper entitled, Exercise and the multidisciplinary holistic approach to adolescent dysautonomia’ (2). We agree that recurrent orthostatic intolerance is often best managed through lifestyle modification rather than pharmacologic intervention (at least as an initial step), and as such in this study, we evaluated the impact of our exercise programme incorporated in addition to our standard clinical multidisciplinary management approach. Currently, our approach incorporates advice to patients and their families regarding the importance of maintaining adequate hydration, salt supplementation, good sleep and nutrition habits, as well as our structured exercise programme. We also provide written literature about living with dysautonomia of adolescence and have the benefit of psychological support for our patients in our Dysautonomia Clinic. While we agree with the importance of patient and family education concerning the incorporation of the management recommendations presented, there is muchwe do not know about how best to implement them. The application of these recommendations to paediatric populations is based on a paucity of direct evidence, and the presumption that children with dysautonomia will respond to management approaches in the same way as adults with dysautonomia, which may not necessarily be the case. As noted, bolus water ingestion (500 mL) acutely improves orthostatic tolerance in healthy controls and patients with neurally mediated (vasovagal) syncope by initiating the osmopressor reflex, but it may not be equally efficacious in both sexes, with some evidence that this is more beneficial for females than males (3). We recommend that our patients with dysautonomia of adolescence drink a minimum of 3 L of fluid per day. Similarly, while salt ingestion (100 mmol/ day) improves orthostatic tolerance through expansion of plasma volume and enhancement of cardiovascular reflex control and cerebral autoregulatory responses in adults with syncope (4), the use, optimal dosing and long-term effects of salt supplementation in children are uncertain; however, we do support the addition of half a teaspoon of salt a day to patients normal diet. There is also controversy concerning the optimal recommendations for the use of compression garments. These garments are often recommended clinically, based upon the assumption that they would ameliorate excessive orthostatic venous pooling and capillary filtration in patients with orthostatic intolerance (5). However, in practice, the most efficacious garments (that compress the abdomen and thighs) are poorly tolerated in terms of patient comfort. Again, their efficacy and suitability for paediatric populations are unclear. Our approach has been that if patients have found benefit from compression stockings prior to our initial assessment, we encourage their ongoing use; however, we do not routinely prescribe them, unless there is a clear indication/trigger. We agree that lifestyle management, in addition to implementationof anexerciseprogramme, is a key component to the management of adolescent dysautonomic. The optimal approaches to be employed and their specific applicability to paediatric populations should be a priority for future research. References 1. Thaxter Nesbeth K. Optimising physiology for adolescents with dysautonomia. Acta Paediatr 2017; 106: 2065. 2. Armstrong KR, De Souza AM, Sneddon PL, Potts JE, Claydon VE, Sanatani S. Exercise and the multidisciplinary holistic approach to adolescent dysautonomia. Acta Paediatr 2017; 106: 612–8. 3. Claydon VE, Schroeder C, Norcliffe LJ, Jordan J, Hainsworth R. Water drinking improves orthostatic tolerance in patients with posturally related syncope. Clin Sci (Lond) 2006; 110: 343–52. 4. Mtinangi BL, Hainsworth R. Early effects of oral salt on plasma volume, orthostatic tolerance, and baroreceptor sensitivity in patients with syncope. Clin Auton Res 1998; 8: 231–5. 5. Protheroe CL, Dikareva A, Menon C, Claydon VE. Are compression stockings an effective treatment for orthostatic presyncope? PLoS ONE 2011; 6: e28193.

ECHO-DOPPLER ASSESSMENT OF AORTIC STIFFNESS IN ADOLESCENT FEMALES WITH ANOREXIA NERVOSA

BACKGROUND: Anorexia nervosa (AN) is associated with cardiovascular complications and abnormalities of biomarkers associated with cardiovascular risk. Arterial stiffness, which is a risk factor for cardiovascular disease, has not been previously studied in patients with AN. This study aimed to determine the biophysical properties of the aorta in adolescent females with AN as compared to control subjects usingDoppler echocardiography. METHODS: This was a retrospective case-control study. Aortic diameter and pulse wave transit time were measured with echoDoppler. Blood pressure was recorded at the time of the echocardiogram. Pulse wave velocity (PWV), aortic input impedance (Zi), characteristic impedance (Zc), arterial pressure-strain elastic modulus (Ep), and arterial wall stiffness index (b-index) were calculated. Patients were divided into those with BMI or > 10th percentile to assess the effect of patient malnutrition on the biophysical properties of the aorta. RESULTS: There were 94 adolescent females with AN and 60 adolescent female controls. There was no difference in age between AN patients and controls (15.5 1.7 vs 15.1 2.6 years, p1⁄40.220). BMI (16.0 2.4vs 19.7 2.7, p 10th percentile. Using multiple linear regression, the only independent predictor of PWV was the presence of AN. CONCLUSION: The increased PWV, which is the most sensitive indicator of vascular dysfunction, indicates increased aortic stiffness in adolescent females with AN compared to controls. Increased PWV was not related to the degree of patient malnutrition. Our study suggests that patients with AN may be at increased risk of future cardiovascular disease. Further studies are required to determine if these changes persist with treatment and to determine long term outcomes.

Optical Coherence Tomography to Assess for Coronary Allograft Vasculopathy in Pediatric Transplant Recipients

s S95 assess cardiac anatomy. Due to the diminutive size of the cardiac structures at this early gestation, 2 Dimensional (2D) imaging alone is often insufficient to identify cardiac anatomy and great vessel relationships. We sought to evaluate the additive benefit of Color Doppler (CD) in addition to routine 2D imaging in early FE before 14 weeks GA. METHODS: From February 2009 we prospectively recruited pregnant women for first trimester FE for a variety of indications including increased nuchal translucency as well as healthy controls. All had 2D cardiac imaging combined with CD assessment. Trans abdominal scanning was used in all cases with trans vaginal scanning used additionally in most cases prior to the 11th week GA (n1⁄492/107, 86%). RESULTS: 254 pregnancies undergoing first trimester FE were included for review. Mean GA at FE was 10+6 weeks (range 6+1 to 13+6 weeks). Significant improvement in image resolution of the fetal heart was gained with every advancing week of gestation. CD significantly improved identification of cardiac arterial outflows and systemic venous inflows from the beginning of the 8th week GA through to the end of the 12th week GA (table 1). Pulmonary venous drainage was not identified in any patient until the 11th week GA. CONCLUSION: When performing early FE, prior to 14 weeks GA, identification of cardiac arterial outflows and systemic venous inflows is greatly improved by the use of color Doppler. When very early FE is performed the use of color Doppler should be routine. WCHRI 021 OPTICAL COHERENCE TOMOGRAPHY TO ASSESS FOR CORONARY ALLOGRAFT VASCULOPATHY IN PEDIATRIC TRANSPLANT RECIPIENTS A Manouzi, MC Hosking, A Fung, A De Souza, JE Potts, KC Harris Vancouver, British Columbia BACKGROUND: Optical Coherence Tomography (OCT) is a highresolution intravascular imaging technique (resolution w 10 microns) that has been used in adults to assess for coronary allograft vasculopathy. The purpose of this study is to describe technical modifications that permit its use in children and compare the coronaryfindings in pediatric transplant recipients to those seen in adults. METHODS: Pediatric cardiac transplant patients were assessed during their routine annual catheterization between December 2012 and April 2013.Modifications weremade to the traditional OCT protocol used in adults in order to adapt this technique to the pediatric population. OCT recordings (Ilumien System, LightLabs,Massachussets)were performed selectively in the right or left coronary artery. Serial measurements of the cross sectional area (CSA) of the lumen, intima and media were made along the length of the vessel. Entire imaging data was analyzed for the presence of mural thrombus, plaque and calcification. We defined the intima-to-media (I/M) area ratio as normal ( 1) or abnormal (>1) as has been done in adult transplant recipients. RESULTS: Seven patients with a history of cardiac transplant were evaluated. The mean age of children was 10.5 years (range 5.5-17) and coronary evaluation was performed a mean of 5.1 years (range 7 months to 15.7 years) following cardiac transplantation. OCT imaging demonstrated intimal thickening in 6/7 (86%) of patients, while conventional angiography was normal in all patients. The median I/M CSA ratio for all patients was 1.25 (0.94-1.79). The intima to lumen CSA ratio was 0.2 in all 7 patients. Intimal thickening was more pronounced in the proximal aspect of the coronaries (figure 1). In contrast to the findings in adults, no other vessel wall abnormalities were identified in this series of children. CONCLUSION: In pediatric cardiac transplant recipients, there are early coronary artery changes seen in the vessel wall with OCT, despite normal selective coronary angiograms. Intimal thickening is present in a significant proportion of children and is most apparent in the proximal coronaries. This is the first description of high-resolution, invivo imaging, of coronary changes in children following cardiac transplantation. 022 CORONARY ARTERY ABNORMALITIES IDENTIFIED WITH OPTICAL COHERENCE TOMOGRAPHY IN CHILDREN WITH KAWASAKI DISEASE A Manouzi, MC Hosking, A Fung, A De Souza, JE Potts, KC Harris Vancouver, British Columbia BACKGROUND: Optical Coherence Tomography (OCT) is an intravascular imaging technique allowing high-resolution S96 Canadian Journal of Cardiology Volume 29 2013 imaging of the lumen and the superficial structure of the vessel wall (resolution w 10 microns). The current evaluation of the cardiac sequelae of Kawasaki Disease (KD) in children predominantly relies on the identification of coronary artery dilation or stenosis based on echocardiography or angiography. METHODS: Patients with a diagnosis of KD with coronary artery dilation were assessed during their planned follow-up catheterization between December 2012 and April 2013. A series of modifications were made to the traditional OCT protocol used in adults in order to adapt this technique to the pediatric population. OCT recordings (Ilumien System, LightLabs, Massachussets) were performed in the right coronary artery. Serial measurements of the cross sectional area (CSA) of the lumen and intima were made at 1mm increments along the length of the vessel. Entire imaging data was analyzed for the presence of mural thrombus and calcification. RESULTS: Cardiac catheterization was performed 11 months to 8.5 years after the diagnosis of KD. Data was collect at 61 points along the right coronary artery in three patients with a history of coronary artery aneurysms. The lumen area was normal (z-score >-2 and 1 at 48% of points analyzed consistent with marked intimal thickening. There was extensive destruction of the internal elastic lamina. CONCLUSION: In this initial experience with OCT in children, we have shown that there are striking coronary artery abnormalities in children with KD despite normal or near normal lumen dimensions. Using conventional imaging techniques these changes would not be identified. The prognostic significance of these changes is not presently known. This is the first description of high-resolution, invivo imaging, of coronary changes in children with KD. 023 THREE-DIMENSIONAL ECHOCARDIOGRAPHIC ASSESSMENT OF THE LONGITUDINAL TRICUSPID VALVE CHANGES ASSOCIATED WITH TRICUSPID REGURGITATION IN HYPOPLASTIC LEFT HEART SYNDROME T Colen, S Kutty, C Vijarnsorn, R Thompson, J Smallhorn, N Khoo