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Background Adults with repaired Tetralogy of Fallot (rTOF) comprise one of the largest cohorts among adults with congenital heart disease (ACHD). These patients have a higher burden of atrial arrhythmias (AA), leading to increased adverse events, including stroke and transient ischemic attack (TIA). However, the data on factors associated with stroke/TIA in rTOF are limited, and classic risk factors may not apply. We studied event rates and associated factors for thromboembolism in a rTOF cohort. Methods Retrospective cohort study of all adult patients age >18 years with rTOF followed at a single ACHD tertiary care center. AA of interest were atrial fibrillation (AF) and atrial flutter (AFL). Results Data from 260 patients were identified, mean age 37.6 SD 13.3 years, followed over 5108 patient‐years (mean 16.6 SD 8.2 years). 43 patients had AF and/or AFL, and 30 patients had thromboembolic events, of which 19 patients had stroke/TIA. The event rate for any thromboembolism was 3.39 per 100 patient‐years follow‐up in patients with AA, compared to 1.80 in patients without (P = .07). In univariate analysis, older age and diabetes were associated with thromboembolic events. In multivariate analysis, only older age was associated with thromboembolic events. Conclusions In our relatively young cohort of adults with rTOF, there was a high prevalence of AA, associated with nearly double the rate of thromboembolic events compared to patients without AA. Older age alone is independently associated with thromboembolic events. Further studies into assessment of silent AA are required, and routine assessments should be considered at an earlier age., There is a high prevalence of atrial arrhythmias in our relatively young cohort of adults with repaired Tetralogy of Fallot. Atrial arrhythmias are associated with twofold increase in risk of thromboembolic events. Older age was identified as a key risk factor, and traditional risk factors were not applicable.

Patients with heritable aortic disease (HAD) have an increased risk of ventricular arrhythmias and sudden cardiac death. Although mitral valve prolapse is common in HAD, mitral annulus disjunction (MAD) has only recently been described in these patients. This under-recognized condition may be a contributing factor to otherwise unexplained ventricular arrhythmias and sudden cardiac death in patients with HAD. This case series describes 3 patients in an adult HAD clinic who have concomitant mitral valve prolapse, MAD, and malignant arrhythmias. These cases may represent a unique disease entity or overlap syndrome, and they introduce MAD as a potential arrhythmogenic risk marker in HAD.

INTRODUCTION Pediatric heart transplant (HTx) recipients have reduced exercise capacity typically two-thirds of predicted values, the mechanisms of which are not fully understood. We sought to assess the cardiorespiratory responses to progressive exercise in HTx relative to controls matched for age, sex, body size, and work rate. METHODS Fourteen HTx recipients and matched controls underwent exercise stress echocardiography on a semisupine cycle ergometer. Hemodynamics, left ventricular (LV) dimensions, and volumes were obtained and indexed to body surface area. Oxygen consumption (V˙O2) was measured, and arteriovenous oxygen difference was estimated using the Fick Principle. RESULTS At rest, LV mass index (P = 0.03) and volumes (P < 0.001) were significantly smaller in HTx, whereas wall thickness (P < 0.01) and LV mass-to-volume ratio (P = 0.01) were greater. Differences in LV dimensions and stroke volume persisted throughout exercise, but the pattern of response was similar between groups as HR increased. As exercise progressed, heart rate and cardiac index increased to a lesser extent in HTx. Despite this, V˙O2 was similar (P = 0.82) at equivalent work rates as HTx had a greater change in arteriovenous oxygen difference (P < 0.01). CONCLUSIONS When matched for work rate, HTx had similar metabolic responses to controls despite having smaller LV chambers and an attenuated increase in hemodynamic responses. These findings suggest that HTx may increase peripheral O2 extraction as a compensatory mechanism in response to reduced cardiovascular function.

Background It has been hypothesized that 4 doses of palivizumab, a neutralizing monoclonal antibody against respiratory syncytial virus (RSV), administered during a fixed-date RSV season may reduce hospital admissions comparably to the standard 5-dose schedule. We report outcomes in children with congenital heart disease approved to receive this 4-dose palivizumab schedule in British Columbia. Methods We performed a population-based descriptive cohort analysis of all 406 approved palivizumab courses over 4 seasons (2012/13 to 2015/16) in 325 children with hemodynamically significant congenital heart disease enrolled in the British Columbia RSV Immunoprophylaxis Program. The primary outcome was in-season hospital admission for potential RSV-related lower respiratory tract infection (LRTI). Secondary outcomes include timing of admission in relation to dosing. Analysis was by intention-to-treat. Results Of the 406 approved palivizumab courses, 391 were administered. In 33 cases (8.4%), an additional dose was given immediately after cardiac bypass surgery. There were 17 RSV-confirmed hospital admissions (median age of children 5.9 mo [interquartile range 4-10 mo]) and 8 admissions in which the child was not tested for RSV, for a maximum of 25 potential RSV-related admissions (6.2 per 100 approvals [95% confidence interval 4.0-9.0]). Twenty-four (96%) of the 25 admissions occurred within the 4-dose palivizumab dosing period, and the remaining admission occurred 52 days after the fourth dose. Sixty-four (72%) of 89 admissions were RSV-negative; the baseline clinical characteristics of these children were not different from those of children with RSV-confirmed admissions. Interpretation In infants with hemodynamically significant congenital heart disease, a 4-dose fixed-date palivizumab schedule over a 6-month season provided seasonal protection comparable to that in a clinical trial involving a standard 5-dose schedule. Because RSV was responsible for only 19% of admissions for LRTI in our cohort, it is critical to continue to emphasize other preventive measures, including family education toward proper hand hygiene, breast-feeding and limiting infectious exposures in children at high risk.

Objective Pediatric heart transplant recipients are at risk of posttransplant coronary artery disease known as cardiac allograft vasculopathy (CAV), and also may develop diastolic dysfunction. As CAV begins with a process of progressive intimal thickening, these occult diffuse changes may be detected using optical coherence tomography (OCT). We hypothesized that the development of CAV, as identified via OCT, may be a mechanism of declining ventricular function. Accordingly, the purpose of this study was to assess coronary artery intimal thickening and LV strain in children who have undergone heart transplantation. Methods In 17 children, we analyzed OCT images for coronary intima and media thickness, and cross-sectional area (CSA). We also performed speckle tracking imaging (STI) of the LV to determine longitudinal strain and strain rate, in addition to standard echocardiographic measures. Results Longitudinal diastolic strain rate was associated with maximum intima thickness (r = -.497, P = .042), intima CSA, (r = -.489, P = .047), maximum media thickness (r = -.503, P = .039), and media CSA (r = -.614, P = .009). The intima maximum thickness, intima/media, and intima/lumen ratios were associated with stroke volume index (Std. β = -0.487, P = .023 and Std. β = -0.488, P = .022, respectively). Conclusions These findings suggest coronary artery intimal thickening may be mechanistically linked to changes in ventricular function following cardiac transplantation.

Purpose Pediatric heart transplant (PHTx) patients require life-long medication and follow up. Adolescents are a vulnerable population with multifactorial reasons for non-adherence to their medical needs. Adherence may depend on the cognitive skills required to plan and to self-regulate, referred to as executive function (EF). Deficits in EF are associated with medication non-adherence. Facilitating consistent communication between adolescents and their health care providers (HCP) via a short messaging service (SMS) platform allows for regular communication and may improve quality of life (QoL) and medication compliance. Methods In collaboration with WelTel, we have implemented a secure, healthcare-specific SMS platform for PHTx aged 12-18 years. At enrollment, EF was assessed by both patient and parent reports using the BRIEF2 (reported global executive composite (GEC) T-score). PedsQL questionnaires and surveys to assess patient engagement with the SMS platform were measured at enrollment and will be reassessed after 1 year. Change in serum immunosuppression levels from baseline to 1 year post SMS intervention will be used as a surrogate measure of medication compliance. Patient response rate and number of care conversations (≥3 messages) were reviewed. Results We report preliminary data on 17 eligible PHTx. Eight have enrolled, 9 in total did not due to a lack of interest (n=2), no access to a cellular phone (n=5), and developmental delay (n=2). At baseline the BRIEF2 did not demonstrate any clinically significant abnormalities in EF, with all scores below the threshold of 70 (mean patient GEC T-score = 52.4, range 39-68; mean parent GEC T-score = 50, range 39-61). Median baseline QoL score was 85 (Range 70-98; healthy adolescents= 83+/-15). Patients have been connected to the SMS network for a median duration of 3.4 months (1.2 - 8.0 months) and there have been a total of 551 messages with 89 that have consisted of a conversation of ≥3 messages. Conclusion We present a novel mode of communication between adolescent PHTx and their healthcare providers. At baseline there is no impairment in EF and QoL is consistent with healthy adolescents. Patients that are enrolled have demonstrated frequent communication using the SMS platform since its introduction. The long-term impact of increased communication on QoL and medication compliance will be reviewed after 1 year.

Background The impact of Fontan circuit thrombus is poorly understood. The objectives of this study were to determine (1) the incidence of Fontan circuit thrombus and proportion of silent thrombus; (2) any association between Fontan circuit thrombus and markers of Fontan circulatory dysfunction; and (3) the association of Fontan circuit thrombus with adverse cardiac outcomes. Methods We conducted a retrospective review of adult patients who underwent the Fontan procedure (aged > 18 years) followed at St. Paul’s Hospital who underwent cardiac computed tomography or magnetic resonance imaging assessment (n = 67). Fontan circulatory dysfunction markers included clinical heart failure, N-terminal pro-brain natriuretic peptide, ventricular dysfunction, atrioventricular valvular regurgitation, refractory arrhythmias, declining exercise capacity, and hepatic/renal dysfunction. Adverse cardiac outcomes were death, heart transplantation, or surgery for Fontan revision or atrioventricular valve replacement. Results Fontan circuit thrombus was present in 15 of 67 patients (22%): 41% (7/17) classic/modified Fontan and 16% (8/50) total cavopulmonary connection. Incidence was 36% among those suspected to have Fontan circuit thrombus; 14% in those with no clinical/echocardiographic suspicion; and clinically silent in 40% diagnosed with Fontan thrombus. The time from Fontan surgery to Fontan circuit thrombus diagnosis was 22 ± 6 years in the classic/modified group vs 14 ± 8 years in the total cavopulmonary connection group (P = 0.03. Fontan circuit thrombus was associated with adverse cardiac outcomes (27% [4/15] vs 8% [4/52], P = 0.02), but there was no difference in Fontan circulatory dysfunction markers. Conclusion Given the incidence of Fontan circuit thrombus and association with adverse cardiac outcomes, routine surveillance of the Fontan circuit should strongly be considered. The identification of thrombus should lead to anticoagulation implementation/optimization, along with screening/intervention for reversible Fontan circulatory issues in an attempt to prevent adverse cardiac outcomes.

As infant and childhood mortality has decreased in congenital heart disease, this population is increasingly reaching adulthood. Adults with congenital heart disease (ACHD) represent a group with increased risk of stroke, silent brain infarcts, and vascular cognitive impairment. Cyanotic and other complex cardiac lesions confer the greatest risk of these cerebrovascular insults. ACHD patients, in addition to having an increased risk of stroke from structural cardiac issues and associated physiological changes, may have an accelerated burden of conventional vascular risk factors, including hypertension and impaired glucose metabolism. Adult neurologists should be aware of the risks of clinically evident and subclinical cerebrovascular disease in this population. We review the existing evidence on primary and secondary stroke prevention in individuals with complex congenital heart disease, and identify knowledge gaps in need of further research, including treatment of acute stroke in this population. Multisystemic genetic syndromes are outside the scope of this review.

ObjectivePatients with Fontan surgery experience late complications in adulthood. We studied the factors associated with the development and maintenance of atrial arrhythmias and thromboembolic complications in an adult population with univentricuar physiology post Fontan surgery.MethodsSingle centre retrospective cohort study of patients ≥18 years of age with Fontan circulation followed at our quaternary care centre for more than 1 year were included. Univariate and multivariate regression models were used where applicable to ascertain clinically significant associations between risk factors and complications.Results93 patients were included (age 30.2±8.8 years, 58% men). 28 (30%) had atriopulmonary Fontan connection, 35 (37.6%) had lateral tunnel Fontan and 29 (31.1%) had extracardiac Fontan pathway. After a mean of 7.27±5.1 years, atrial arrhythmia was noted in 37 patients (39.8%), of which 13 developed had atrial fibrillation (14%). The presence of atrial arrhythmia was associated with the number of prior cardiac surgeries/procedures, increasing age and prior atriopulmonary Fontan operation. Thromboembolic events were present in 31 patients (33%); among them 14 had stroke (45%), 3 had transient ischaemic attack (9.7%), 7 had pulmonary embolism (22.6%) and 5 had atrial thrombus with imaging (16.1%). The presence of thromboembolic events was only associated with age and the presence of cirrhosis in multivariate analysis.ConclusionsAtrial arrhythmias are common in adults with Fontan circulation at an early age, and are associated with prior surgical history and increasing age. Traditional risk factors may not be associated with atrial arrhythmia or thromboembolism in this cohort.

Background: Atrial arrhythmias (AA) are common in adults with congenital heart disease (ACHD). Although Intra-atrial Reentrant Tachycardia (IART) is well described in ACHD, Atrial Fibrillation (AF) is uncommon, but increasingly recognized. Patients with Transposition of the Great Arteries (TGA) and congenitally corrected-TGA (CC-TGA) have a high burden of AA at a relatively young age. However, long-term data of AA and associated thromboembolic risk are lacking in these patients. The prevalence, associated clinical factors, and complications of AA in a longitudinal TGA cohort was studied. Methods: A retrospective cohort study of all TGA patients from a single tertiary care centre was conducted. Data regarding documented atrial arrhythmias, thromboembolic events, and factors associated with thromboembolism were extracted and analyzed. Mean values and standard deviations were calculated for normally distributed continuous variables. When frequencies and means were compared, the chi-squared test and student t-test were used, respectively. Results: One-hundred twenty-five patients with TGA (76 TGA, 49 CC-TGA) were followed for a mean of 20.8 ± 13.2 years. AF was confirmed in 20% (n = 25) and there were 5 (20%) thromboembolic complications within the AF population. AF was associated with an annual thromboembolic event rate of 2.7%/year (stroke/transient ischemic attack 1.7%, systemic embolism 1.0%). Conclusion: AF is relatively common in the TGA ACHD population in long-term follow up. Although annual risk of thromboembolism is low in this young group of patients, life-time cumulative risk is potentially high. TGA patients should be screened actively for AF and appropriate anticoagulation therapy initiated. It is unclear if established risk prediction scores in other non-valvular AF populations may be applicable to this cohort.

BACKGROUND: Respiratory Syncytial Virus (RSV) is a leading cause of hospital admission for acute lower respiratory tract infections (LRTI) in young children. Infants with congenital heart disease (CHD) are at a higher risk of severe infection, specifically those with hemodynamically significant intra-cardiac shunts, impaired cardiac function or pulmonary hypertension. Palivizumab prevents RSV-related hospitalizations in children with higher risk indications, including CHD, however the number of doses required to achieve optimal protection remains controversial. We report the clinical outcomes of children with CHD who received an abbreviated Palivizumab 4-dose schedule, with an increased inter-dose interval in our region. OBJECTIVES: To report hospitalization outcomes in children with CHD who received an abbreviated 4-dose Palivizumab dose schedule through the centrally managed regional RSV Immunoprophylaxis Program. DESIGN/METHODS: Retrospective population-based study of children with CHD enrolled into the regional RSV Program between 2012–2016. Children received palivizumab between November and April. Eligibility was defined according to our provincial guidelines and this defined our sample size. The primary outcome was in-season hospitalizations for RSV-confirmed or potentially RSV-related (unknown) LRTI determined by cross referencing the RSV Program database and the Canadian Institute of Health Informatics (CIHI) discharge abstract database (DAD) using seven RSV-related ICD-10 diagnostic codes. Children were categorized according to CHD subtype. Analysis was by intention-to-treat. RESULTS: A total of 325 children ([mean ± SD] gestational age 37.9±6.2 weeks; birth weight 2870±871 grams) were approved to receive 406 palivizumab courses. Between November 2012 and April 2016, 89 hospitalizations occurred in CHD patients. Of this, seventeen were RSV-confirmed hospitalizations (median age 5.9 [IQR 4 to 10]months); 8 additional cases were not tested for RSV, for a maximum rate of hospitalizationsfor RSV-confirmed or unknown of 6.2 per 100 approvals (95%CI: 4.0 to 9.0%). 24/25 RSV-confirmed or potentially RSV-related hospitalizations occurred before the 4(th)Palivizumab dose. Only one RSV-confirmed hospitalization occurred (52 days) after the 4th Palivizumab dose. Clinical characteristics of children with RSV-confirmed hospitalizations (n=17) were similar to those with RSV-unrelated hospitalizations (n=40). CONCLUSION: Our data provide population-based evidence of the protection achieved by a 4-dose Palivizumab dose schedule in infants with CHD. This clinical practice yields substantial benefits to children, their families, and to the health care system, such as reduced visits, injections, and costs, compared to a standard 5-dose schedule. Our results warrant confirmation in other geographic areas.

Background Chronic hemodynamically relevant pulmonary regurgitation (PR) resulting in important right ventricular dilation and ventricular dysfunction is commonly seen after tetralogy of Fallot (TOF) repair. Late adverse clinical outcomes, including exercise intolerance, arrhythmias, heart failure and/or death accelerate in the third decade of life and are cause for considerable concern. Timing of pulmonary valve replacement (PVR) to address chronic PR is controversial, particularly in asymptomatic individuals, and effect of PVR on clinical measures has not been determined. Methods Canadian Outcomes Registry Late After Tetralogy of Fallot Repair (CORRELATE) is a prospective, multicentre, Canada-wide cohort study. Candidates will be included if they are ≥ 12 years of age, have had surgically repaired TOF resulting in moderate or severe PR, and are able to undergo cardiovascular magnetic resonance imaging. Enrollment of > 1000 individuals from 15 participating centres (Toronto, Montreal, Quebec City, Sherbrooke, Halifax, Calgary, Edmonton, and Vancouver) is anticipated. Clinical data, health-related quality of life metrics, and adverse outcomes will be entered into a web-based database. A central core lab will analyze all cardiovascular magnetic resonance studies (PR severity, right ventricular volumes, and ventricular function). Major adverse outcomes (sustained ventricular tachycardia and cardiovascular cause of death) will be centrally adjudicated. Results To the best of our knowledge, CORRELATE will be the first prospective pan-Canadian cohort study of congenital heart disease in children and adults. Conclusions CORRELATE will uniquely link clinical, imaging, and functional data in those with repaired TOF and important PR, thereby enabling critical evaluation of clinically relevant outcomes in those managed conservatively compared with those referred for PVR.

Objectives 1) To determine the accuracy of estimated GFR (eGFR) as compared to directly measured GFR (mGFR) in the adult Fontan population; 2) to determine the true prevalence of chronic kidney damage (CKD) as determined by uACR AND eGFR. Methods Prospective study of 81 patients Fontan patients (≥18years) followed at St. Paul's Hospital, University of British Columbia. CKD-EPI and MDRD equations used to calculate eGFR, mGFR determined by 99m Tc-DTPA renal dynamic imaging and urine albumin to creatinine ratios were calculated. Results The mGFR was 93±27ml/min/1.73m 2 : 28 (53%) had an mGFR 2 and 1 (2%) had an mGFR 2 . There was a modest correlation between mGFR and eGFR (EPI/MDRD) (r=0.50, p 2 , p 2 , p 90ml/min/1.73m 2 , 50% and 46% respectively had an mGFR 2 . Significant albuminuria (>3mg/mmol) was present in 33% and upwards of 32% of patients with a normal eGFR (MDRD/EPI) had evidence of CKD with uACR >3mg/mmol. Using combined criteria of eGFR 2 and/or uACR >3mg/mmol, 46% of patients had evidence of CKD. Conclusions This study draws attention to the need for stringent CKD screening as an important proportion of CKD is currently not being detected. Mild undetected CKD, an early marker of end organ damage, may also be an early sign of Fontan failure that requires warrants further research.

Background In a cohort of congenitally corrected transposition of the great arteries (cc-TGA) and transposition of the great arteries after atrial switch procedure (d-TGA) the study objectives were: 1) to assess the change of quantitative systemic right ventricle (sRV) parameters over time and; 2) to examine the relationship of quantitative sRV parameters with adverse clinical outcomes. Methods and results Single-center cohort study that included 49 (39%) cc-TGA and 76 (61%) d-TGA patients >18years who had at least one MUGA sRV assessment, 18/39 had more than one respectively. The primary clinical endpoint was all-cause mortality, heart transplantation and/or heart failure hospitalization. At a median clinical follow-up of 7years following the first MUGA, the primary endpoint occurred more often in cc-TGA versus d-TGA patients (18 (36.7%) vs. 9 (11.8%), p=0.03). Median time between the MUGA assessments was 5.8 (cc-TGA) and 4.9years (d-TGA). At last MUGA follow-up: 6 (33%) cc-TGA/14 (36%) d-TGA patients showed a significant decline in sRVEF (>5%); 6 (33%) cc-TGA/17 (44%) d-TGA patients had a significant increase in sRVEDVi; and 7 (39%) cc-TGA/19 (49%) PA-TGA patients had a significant increase in sRVESVi. Baseline sRV parameters were not associated with the primary end point or sRV changes over time. Conclusions An important proportion of both patient cohorts demonstrated a significant change in sRV parameters over time and these are likely related to multiple factors that vary between individuals given population heterogeneity. The TGA patients have distinct clinical trajectories with increased adverse heart failure outcomes in the cc-TGA population and sRV parameters were not related to adverse heart failure events in either group.

BACKGROUND:Acetylsalicylic acid (ASA) is part of the recommended treatment of Kawasaki disease (KD). Controversies remain regarding the optimal dose of ASA to be used. We aimed to evaluate the noninferiority of ASA at an antiplatelet dose in acute KD in preventing coronary artery (CA) abnormalities.METHODS:This is a multicenter, retrospective, nonrandomized cohort study including children 0 to 10 years of age with acute KD between 2004 and 2015 from 5 institutions, of which 2 routinely use low-dose ASA (3–5 mg/kg per day) and 3 use high-dose ASA (80 mg/kg per day). Outcomes were CA abnormalities defined as a CA diameter with a z score ≥2.5. We assessed the risk difference of CA abnormalities according to ASA dose. All subjects received ASA and intravenous immunoglobulin within 10 days of fever onset.RESULTS:There were 1213 subjects included, 848 in the high-dose and 365 in the low-dose ASA group. There was no difference in the risk of CA abnormalities in the low-dose compared with the high-dose ASA group (22.2% vs 20.5%). The risk difference adjusted for potential confounders was 0.3% (95% confidence interval [CI]: −4.5% to 5.0%). The adjusted risk difference for CA abnormalities persisting at the 6-week follow-up was −1.9% (95% CI: −5.3% to 1.5%). The 95% CI of the risk difference of CA abnormalities adjusted for confounders was within the prespecified 5% margin considered to be noninferior.CONCLUSIONS:In conjunction with intravenous immunoglobulin, low-dose ASA in acute KD is not inferior to high-dose ASA for reducing the risk of CA abnormalities.

Background Exercise testing in children is widely recommended for a number of clinical and prescriptive reasons. Many institutions continue to use the Bruce protocol for treadmill testing; however, with its incremental changes in speed and grade, it has challenges for practical application in children. We have developed a novel institutional protocol (British Columbia Children’s Hospital (BCCH)), which may have better utility in paediatric populations. Aim To determine if our institutional protocol yields similar peak responses in minute ventilation (VE), oxygen consumption (VO 2 ), carbon dioxide production (VCO 2 ), respiratory exchange ratio (RER), metabolic equivalents (METS) and heart rate (HR) when compared with the traditional Bruce protocol. Methods On two different occasions, 70 children (boys=33; girls=37) aged 10–18 years completed an exercise test on a treadmill using each of the protocols. During each test, metabolic gas exchange parameters were measured. HR was monitored continuously during exercise using an HR monitor. Results Physiological variables were similar between the two protocols (median (IQR); r s ): VE (L/min) (BCCH=96.7 (72.0–110.2); Bruce=99.2 (75.6–120.0); r s =0.95), peak VO 2 (mL/min) (BCCH=2897 (2342–3807); Bruce=2901 (2427–3654); r s =0.94) and METS (BCCH=16.2 (14.8–17.7); Bruce=16.4 (14.7–17.9); r s =0.89). RERs were similar (BCCH=1.00 (0.96–1.02); Bruce=1.03 (0.99–1.07); r s =0.48). Total exercise time (in seconds) was longer for the BCCH protocol: BCCH=915 (829–1005); Bruce=810 (750-919); r s =0.67. Conclusion The BCCH protocol produces similar peak exercise responses to the Bruce protocol and provides an alternative for clinical exercise testing in children.

Purpose The primary goal of pediatric heart transplantation (PHTx) is to improve the quality of life (QoL) of patients. National physical activity guidelines for adolescents recommend at least 60-90 minutes of moderate to vigorous physical activity per day. The Physical Activity Questionnaire (PAQ-C/A) for children and adolescents provides general estimates of physical activity levels. Measurement of peak aerobic capacity (VO2peak) using cardiopulmonary exercise testing (CPX) is the gold standard for assessing exercise capacity. Both physical activity and exercise capacity may be important factors that influence reporting a normal QoL. Our aim was to determine if there was a relationship between physical activity, exercise capacity, and QoL in a PHTx adolescent population. Methods This is a single centre retrospective chart review of adolescent (11-18 yrs) PHTx patients. Those who completed a maximal CPX test (RER>1.0), self-report physical activity (PAQ-C or PAQ-A) and QoL (PedsQL and PedsQL-Transplant) questionnaires, as part of their annual assessment, were eligible for inclusion. Results were compared to published age- and sex-matched healthy control data used in our laboratory. VO2peak and QoL were deemed to be normal if results were within two standard deviations of the mean. Pearson correlation coefficients were calculated. Medians and interquartile ranges are reported. Results Thirteen PHTx (10 males) completed a CPX and both QoL questionnaires. The median age was 14.9 yrs (12.3-17.5 yrs). VO2peak=34.5 mL/min/kg (30.2-43.4 mL/min/kg. Only 1 of 13 had an abnormal VO2peak. Total Peds QL score=84.8 (68.5-92.4) with 10 out 13 reporting a normal QoL. The Peds QL-Transplant score=90.5 (84.8-95.1). There was no significant correlation between VO2peak and QoL. The PAQ-C/PAQ-A was completed in 10 HTx. PAQ scores=2.38 (1.59-3.01). Only 2 of 13 met the cut-off point (>2.87) for adequate physical activity. There was a significant correlation between the Peds QL-Transplant QoL and the PAQ (r=0.69; p=0.04) Conclusion PHTx adolescents do not meet their required physical activity recommendations. Despite this, they have low normal exercise capacity and report a normal QoL. Efforts to engage adolescents to increase their physical activity should be encouraged.

Background Management of adults with congenital heart disease (ACHD) requires quaternary centres with cardiologists and cardiac surgeons who have expertise in the diagnosis and management of this patient population. We report on the feasibility of the management of ACHD patients using videoconferencing and streaming through 1 regional referral centre covering 4 western Canadian provinces, roughly 30% of Canada's land and population. Methods Videoconferencing sessions from January 2008 to December 2010 were systematically reviewed. Case presentations were classified as successful or unsuccessful. All patients were followed to assess whether the recommendations were acted upon. The hosting institution used the Alberta Health Services internet protocol network, while other connections used integrated service digital network. The videoconference equipment at the different sites includes Polycom HDX 9000 (Polycom, San Jose, CA), Tandberg Edge 95 (Tandberg, San Jose, CA), and Tandberg 990 (Tandberg). Results From January 2008 to December 2010 there were 26 sessions, 213 case presentations, and 177 patients discussed with an average 8.2 case presentations per session. Thirty-two case presentations were deferred, 10 of which were because of transmission errors and the remainder were because of unavailability of staff or images. Of the 177 recommendations, 124 procedures (91 surgical, 29 percutaneous, and 4 electrophysiological) were booked directly at the regional referral centre. Only 6 recommendations were not carried out (4 because of premature deaths, and 2 because of patient logistic issues). Conclusions The results of this study illustrate that telehealth is a feasible medium for arriving at consensus recommendation in the management of ACHD patients living in a geographically diverse area.

Congenital heart disease is the most common congenital malformation and approximately 3 in 1000 newborns have critical congenital heart disease (CCHD). Timely diagnosis affects morbidity, mortality, and disability, and newborn pulse oximetry screening has been studied to enhance detection of CCHD. In this position statement we present an evaluation of the literature for pulse oximetry screening. Current detection strategies including prenatal ultrasound examination and newborn physical examination are limited by low diagnostic sensitivity. Pulse oximetry screening is safe, noninvasive, easy to perform, and widely available with a high specificity (99.9%) and moderately high sensitivity (76.5%). When an abnormal saturation is obtained, the likelihood of having CCHD is 5.5 times greater than when a normal result is obtained. The use of pulse oximetry combined with current strategies has shown sensitivities of up to 92% for detecting CCHD. False positive results can be minimized by screening after 24 hours, and testing the right hand and either foot might further increase sensitivity. Newborns with abnormal screening results should undergo a comprehensive assessment and echocardiography performed if a cardiac cause cannot be excluded. Screening has been studied to be cost neutral to cost effective. We recommend that pulse oximetry screening should be routinely performed in all healthy newborns to enhance the detection of CCHD in Canada.

Background. Hepatic fibrosis is a potential complication following Fontan surgery and heralds long-term risk for cirrhosis. Transient elastography (TE) is a rapid, noninvasive method to assess liver fibrosis by measuring liver stiffness.Objectives. To compare liver stiffness and liver biochemistries in pediatric Fontan patients with age- and sex-matched controls and to determine patients’ acceptance of TE.Methods. Patients were recruited from British Columbia Children’s Hospital. Twenty-two Fontan patients (15 males) were identified. Demographic information and cardiac data were collected. TE was measured using size-appropriate probes.Results. The median age of the Fontan cohort was 13.7 (5.9–16.8) years. Time from Fontan surgery to TE was 9.6 (1.0–12.9) years. The median Fontan circuit pressure was 13 (11–14) mmHg. TE values were higher in Fontan patients versus controls (18.6 versus 4.7 kPa,p<0.001). There was no association between TE values and patient age (r=0.41,p=0.058), time since Fontan surgery (r=0.40,p=0.062), or median Fontan circuit pressure (CVP) (r=0.35,p=0.111). Patients found TE to be nonpainful, convenient, and safe.Conclusions. TE is feasible to assess liver stiffness in children following Fontan surgery. Pediatric Fontan patients have markedly elevated liver stiffness values. TE may have important utility in liver care follow-up of pediatric Fontan patients.

Acquired left ventricular aneurysm is extremely rare in children. This report describes an infant with acquired left ventricular aneurysm after percutaneous aortic balloon valvuloplasty for critical aortic stenosis. The potential risk factors for myocardial injury during cardiac catheterization and potential complications are discussed.

Yeung JP, Human DG, Sandor GGS, De Souza AM, Potts JE. Serial measurements of exercise performance in pediatric heart transplant patients using stress echocardiography. Pediatr Transplantation 2011: 15: 265–271. © 2011 John Wiley & Sons A/S. Abstract: Heart transplantation is an increasingly acceptable therapeutic option for children with end-stage and complex congenital heart disease. With advances in surgery, immunosuppression, and follow-up care, functional outcomes need to be evaluated. We report the results of serial exercise testing performed using stress echocardiography in a cohort of pediatric HTP. HTP (n = 7) exercised on a semi-recumbent ergometer to volitional fatigue. Echocardiography-Doppler measurements, HR, and blood pressure were taken at rest and during staged exercise. Results were compared with healthy CON (n = 12). HTP did significantly less work during exercise (940 vs. 1218 J/kg, p

Costello syndrome is characterized by constitutional mutations in the proto-oncogene HRAS, causing dysmorphic features, multiple cardiac problems, intellectual disability, and an increased risk of neoplasia. We report a male infant with dysmorphic features, born prematurely at 32 weeks, who, during his 3-month life span, had an unusually severe and ultimately fatal manifestation of hypertrophic cardiomyopathy and hyperinsulinemic hypoglycemia. Molecular studies in this patient demonstrated the uncommon Q22K mutation in the HRAS gene, diagnostic of Costello syndrome. The major autopsy findings revealed hypertrophic cardiomyopathy, congenital myopathy, and a 1.4-cm pancreatic nodule that was positive for insulin expression and morphologically identical to a focal lesion of congenital hyperinsulinism. Sequencing of KCNJ11 and ABCC8, the 2 most commonly mutated genes in focal lesion of congenital hyperinsulinism, revealed no mutations. While hyperinsulinism is a recognized feature of RASopathies, a focal proliferation of endocrine cells similar to a focal lesion of hyperinsulinism is a novel pathologic finding in Costello syndrome.

We present a case series of pediatric blunt cardiac trauma with a variety of cardiac abnormalities, occurring immediately and after the initial insult. The range of complications and importance of serial evaluations are emphasized.

A 4-month-old child with severe infantile Marfan syndrome underwent successful repair of an extremely dilated aortic root and severe aortic valve insufficiency using a prosthetic valved conduit.

To describe the clinical features, diagnosis, treatment and outcome of children with Kawasaki disease (KD) treated at a large tertiary care Canadian paediatric hospital and to try to identify correlations between clinical features and the development of coronary artery abnormalities.The charts of 176 patients diagnosed with typical, atypical or incomplete KD between 1992 and 2000 at British Columbia's Children's Hospital were reviewed.The male to female ratio was 1.8:1. The median age was 2.5 years (range two months to 14 years), with 8% nine years or older (42% Caucasian, 43% Asian). Cases occurred steadily throughout the year. One hundred two (58%) patients had typical, 18 (10%) patients had atypical and 56 (32%) patients had incomplete KD. The median time from fever onset to first intravenous immunoglobulin (IVIG) was seven days (range two to 49 days), and treatment began within 10 days of fever onset in 134 (76%) patients. All patients received one or more doses of 2 g/kg IVIG. Forty-two (24%) patients received a second dose for nonresponsiveness, of whom 10 (6%) remained nonresponsive. Eight (5%) patients received intravenous methylprednisolone. Forty-eight (27%) patients developed coronary artery abnormalities, with 10 (6%) echogenic abnormalities, 25 (14%) dilatations and 13 (7%) aneurysms (seven giant). No patient with a normal echocardiogram at four to eight weeks developed an abnormality on subsequent study. Fourteen (8%) patients had persistent abnormalities at last follow-up (median 447 days, range 62 to 3272 days): seven dilations and seven aneurysms (six giant). Five of 13 children (39%) who developed aneurysms failed to meet diagnostic criteria for typical KD, and three of those five aneurysms were present at less than one year after diagnosis. Four of eight (50%) patients receiving intravenous methyl-prednisolone for IVIG nonresponsiveness had or developed aneurysms. One patient died.Some children diagnosed with KD who fail to meet the diagnostic description develop coronary artery abnormalities. There is a need for a more accurate means of diagnosis to more appropriately use IVIG, an expensive and increasingly scarce resource. The role of corticosteroids remains unclear and a randomized controlled clinical trial to determine their role is needed.

Background. Expensive devices are increasingly used to close a patent fenestration after a modified Fontan operation. We report our 5-year institutional experience of clipped tube fenestration after extracardiac Fontan operation, which allows for simple transcatheter coil occlusion. Methods. We retrospectively reviewed 30 children, median age of 4.0 years (range, 2.4 to 8.8 years) who underwent extracardiac Fontan operation between May 1996 and May 2001, and were fenestrated using a 4- to 8-mm diameter clipped tube graft. Results. Ten children had a patent fenestration occluded by transcatheter placement of 15 detachable coils (5- to 8-mm diameter). Aortic oxygen saturations increased on average by 5.5% (2% to 14%) and mean pressures in the Fontan circuit by 2.5 mm Hg (0 to 3 mm Hg). Four had immediate complete occlusion angiographically and 6 had trivial residual shunt, but complete occlusion by echocardiography at follow-up. There have been no immediate complications, late coil embolizations, thromboembolic events, or documented hemolysis within a follow-up after coil implantation of 1.7 years (0.4 to 4.5 years). Spontaneous fenestration closure was documented in 8 patients at cardiac catheterization and 9 patients by echocardiography with consistent improvement in resting transcutaneous oxygen saturation. Two children with a patent fenestration have been considered inappropriate for closure, and there was one early surgical death. There have been no complications related to the tube fenestration modification within a follow-up postoperation of 2.6 years (0.1 to 5.5 years). Conclusions. Clipped tube fenestration after extracardiac Fontan operation is a useful surgical modification that allows for simple transcatheter coil occlusion.

Background — Maternal anti-Ro and anti-La antibodies are associated with congenital heart block (CHB). Although endocardial fibroelastosis (EFE) has been described in isolated cases of autoantibody-mediated CHB, the natural history and pathogenesis of this disease are poorly understood. Methods and Results — We retrospectively reviewed the clinical history, echocardiography, and pathology of fetuses and children with EFE associated with CHB born to mothers positive for anti-Ro or anti-La antibodies at 5 centers. Thirteen patients were identified, 6 with a prenatal and 7 with a postnatal diagnosis. Six mothers were positive for anti-Ro and anti-La antibodies, and 7 were positive for anti-Ro antibodies only. Only 1 mother had autoimmune disease. Severe ventricular dysfunction was seen in all fetal and postnatal cases. Four fetal and 3 postnatal cases had EFE at initial presentation. However, 2 fetal and 4 postnatal cases developed EFE 6 to 12 weeks and 7 months to 5 years from CHB diagnosis, respectively, even despite ventricular pacing in 6 postnatal cases. Eleven (85%) either died (n=9) or underwent cardiac transplantation (n=2) secondary to the EFE. Pathologic assessment of the explanted heart, available in 10 cases, revealed moderate to severe EFE in 7 and mild EFE in 3 cases, predominantly involving the left ventricle. Immunohistochemistry in 4 cases (including 3 fetuses) demonstrated deposition of IgG in 4 and IgM in 3 and T-cell infiltrates in 3 cases, suggesting an immune response by the affected fetus or child. Conclusions — EFE occurs in the presence of autoantibody-mediated CHB despite adequate ventricular pacing. Autoantibody-associated EFE has a very high mortality rate, whether developing in fetal or postnatal life.

OBJECTIVESWe report on the early and intermediate-term follow-up results of self-expanding Wallstent (Schneider, Switzerland) implanted in children with congenital heart disease.BACKGROUNDThe inherent shortcomings of balloon-expandable stents prompted the trial of an alternative stent.METHODSTwenty patients underwent 22 implantations of 25 self-expanding Wallstents between December 1993 and June 1997 in two institutions. The mean age and weight were 10.8 ± 4.5 years and 30.5 ± 14.2 kg, respectively. The patients were divided into two groups: 1) Group I comprised 17 patients with pulmonary arterial stenoses, 2) Group II comprised four patients with venous stenoses (one belonged to both groups). Sixteen patients underwent recatheterization at a median of 5.8 months (range 0.5 to 31, mean 8.1 months) after stenting. Hemodynamic and angiographic changes after the interventional procedures and complications were documented.RESULTSAll the stents were successfully deployed in the intended position. In Group I, the narrowest diameter of the stented vessel increased from 4.1 ± 1.5 to 8 ± 2 mm (95% increase, p < 0.0001) while the systolic pressure gradient across decreased from 24.6 ± 15.8 to 12.1 ± 11.4 mm Hg (51% decrease, p = 0.001). In Group II, the dimensional changes of the narrowest segment increased from 4.3 ± 0.5 to 7.5 ± 0.4 mm (75% increase, p = 0.003), and the pressure gradient reduced from 5.0 ± 2.9 to 0.9 ± 1.0 mm Hg (82% decrease, p = 0.04) across the stented venous channel. Distal migration of two optimally positioned stents occurred within 24 h of implantation. At recatheterization, significant neointimal ingrowth (>30% of the expanded diameter) was noted in 7 (28%) of the 25 implanted stents. This responded poorly to balloon dilation. Predisposing factors for the neointimal ingrowth included stents of smaller diameter (

Pediatric heart failure (HF) is an important cause of morbidity and mortality in childhood. This article presents guidelines for the recognition, diagnosis, and early medical management of HF in infancy, childhood, and adolescence. The guidelines are intended to assist practitioners in office-based or emergency room practice, who encounter children with undiagnosed heart disease and symptoms of possible HF, rather than those who have already received surgical palliation. The guidelines have been developed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, and are accompanied by practical Recommendations for their application in the clinical setting, supplemented by online material. This work does not include Recommendations for advanced management involving ventricular assist devices, or other device therapies.

Heart transplantation is an increasingly acceptable therapeutic option for children with end-stage and complex congenital heart disease. With advances in surgery, immunosuppression, and follow-up care, functional outcomes need to be evaluated. We report the results of serial exercise testing performed using stress echocardiography in a cohort of pediatric HTP. HTP (n = 7) exercised on a semi-recumbent ergometer to volitional fatigue. Echocardiography-Doppler measurements, HR, and blood pressure were taken at rest and during staged exercise. Results were compared with healthy CON (n = 12). HTP did significantly less work during exercise (940 vs. 1218 J/kg, p0.03). Their SVI (33 vs. 49 mL/m(2), p0.003), CI (5.16 vs. 9.25 L/min/m(2), p0.0005), and HR (162 vs. 185 bpm, p0.02) were lower at peak exercise. HTP had a lower SF at peak exercise (48% vs. 52%, p0.03) and an abnormal relationship between the MVCFc and σPS. During follow-up, hemodynamics and left ventricular function remained relatively constant in HTP. HTP are able to exercise safely; however, their exercise tolerance is reduced, and hemodynamics and contractility are diminished. Over time, their hemodynamics and left ventricular function have remained relatively constant.

Sixty-six patients operated on previously for coarctation of the aorta were included in the study. There were 50 children and 16 adults. Invasive and non-invasive gradients were recorded. Anatomical obstruction was evaluated by angiography in 54 patients and the numbers and size of collaterals were quantified. The closest correlation was found between Doppler-estimated gradients and invasive peak-instantaneous gradients (r = 0.87). The relation between anatomical obstruction and invasive peak-to-peak gradients, Doppler gradients and diastolic flow ere discouraging (r = 0.64, 0.54 and 0.35). Liberal indications for angiography or magnetic resonance tomography are recommended.

Summary. The aim of the study was to compare invasive and non-invasive blood pressure measurements and gradients. Twenty-two children and 16 adults previously operated for coarctation of the aorta were included. Invasive blood pressures were recorded proximally and distally close to the former operation site and non-invasive systolic blood pressures were recorded by an automated sphygmomanometer on right arm and leg. The adults were investigated at rest and during supine exercise. The correlation between invasive and non-invasive measurements of proximal blood pressures in adults at rest and children were the following, r= 0.92, SD 7.6 mmHg (n= 16) and r= 0.85, SD 11 mmHg (n= 22) respectively. The corresponding correlation for the distal blood pressures were the following for adults at rest 0.64, SD 11.9 mmHg and in children /- = 0.82, SD 9.2 mmHg. During exercise in adults we found a low correlation when comparing invasive and non-invasive proximal and distal blood pressures and a poor correlation regarding the gradients, r= 0.50, SD 16 mmHg, r= 0.45, SD 15.9 mmHg and r= 0.30, SD 22.9 mmHg respectively (n= 16). We also measured the time interval between cessation of exercise and completion of the blood pressure recordings, which gave a mean interval of 73 sec (range 45–115 sec). During that interval the mean fall in the proximal blood pressure was 37 mmHg (range 20–80 mmHg), and the mean fall of the gradient was from 41 mmHg (range 20–76 mmHg) to 23 mmHg (range 6–56 mmHg). We conclude that the non-invasive estimation of proximal blood pressures gave fair results but that the estimation of gradients are unsatisfactory. The use of this method to predict exercise induced blood pressures changes and gradients seems highly unreliable.

We describe and illustrate a rare association of hypoplastic left heart syndrome, absent hilar left pulmonary artery, and an unusual bronchopulmonary malformation. This case highlights the utility of combination imaging of echocardiography and CT angiography in diagnosing a cyanotic newborn with a chest radiograph that is suspicious for lung hypoplasia.

A child with complex congenital heart disease in 2008 is very likely to survive a series of surgical and medical interventions, and confront an array of medical and psychosocial stressors that are presently poorly understood. As approaches to medical problems change, careful assessment of those results is essential, and the initial work of the multicentre Pediatric Heart Network is a huge step in the right direction, setting the stage for proper controlled trials of therapies. Major complications, notably ventricular failure, rhythm problems and thromboembolism, will affect nearly one-quarter of survivors, necessitating further interventions. Appropriate educational and psychosocial support for these children and their families is the next challenge for all of us in the field of paediatrics. How ironic would it be to have invested so much in early survival, only to allow the child to fail in life itself.

Enzyme replacement therapy (ERT) has been increasingly used as an interim treatment in severe mucopolysaccharidosis type I (MPSI)/Hurler patients prior to hematopoietic stem cell transplantation (HSCT).We present the outcome of a patient with MPSI/Hurler after 14 months of ERT prior to HSCT.Urinary glucosaminoglycan excretion decreased by 70% after one month of ERT. Liver volume decreased by 14% of baseline after 12 months of ERT. Pre-existing thoracolumbar kyphosis progressed to thoracolumbar dislocation with complete displacement of facets after 12 months of ERT. New development of mitral valve thickening was found by echocardiography and mild hearing loss progressed to severe sensorineural hearing loss after 13 months of ERT.ERT over a period of 14 months did not prevent progression of organ manifestations in our patient. Patients should be monitored every 6 months for cardiac, skeletal and audiological involvement on ERT.

Fifteen children with aortic stenosis were examined with Echo-Doppler cardiography in order to evaluate the use of the continuity equation to calculate the aortic valve area. The results were compared to invasive estimates of valve area calculated with the Gorlin's equation. A close correlation between the two methods, r = 0.94, was found and it is concluded that even in children an accurate estimate of valve area can be expected with the use of the continuity equation.