Deborah Fruitman

Spontaneous Rupture of Atrioventricular Valve Tensor Apparatus as Late Manifestation of Anti-Ro/SSA Antibody-Mediated Cardiac Disease

Atrioventricular (AV) block and endocardial fibroelastosis associated with dilated cardiomyopathy are the most common clinical manifestations of anti-Ro/SSA-mediated fetal cardiac disease. Valvar dysfunction has not been a prominent feature of this disease; however, recent anecdotal cases have suggested an association between rupture of the AV valve tensor apparatus and maternal anti-Ro/SSA antibodies. In the present study, we have described the clinical and laboratory findings and reviewed the published data for infants of anti-Ro/SSA-positive pregnancies with AV valve insufficiency due to chordal rupture from the papillary muscles. The histopathologic features of the papillary muscle and ventricular free wall and septum biopsy specimens were examined and compared to the sections of AV leaflets from 6 autopsied fetuses with anti-Ro/SSA-mediated complete AV block without chordal disruption. Specific epitopes to the p200 region of Ro52, and Ro60 antibodies were evaluated in cases with chordal rupture. Severe AV valve insufficiency was detected prenatally (as early as 34 weeks of gestation) or postnatally (as late as 182 days) after areas of patchy echogenicity were noted in the papillary muscle at 19 to 22 weeks of gestation. Postnatally, urgent valve surgery was performed in 5 of 6 patients; 1 of 6 patients died preoperatively. All patients tested positive for Ro52. Valve leaflet tissue from the autopsy specimens was normal. The ventricular free wall and septum biopsy specimens from a patient with chordal rupture showed normal tissue; however, the papillary muscle biopsy specimens demonstrated severe atrophy with near total replacement of myocytes by fibrosis and dystrophic calcifications, and negative immunochemistry findings. In conclusion, these findings have defined an underappreciated complication of fetal antibody-mediated cardiac inflammation.

The evolving approach to paediatric myocarditis: a review of the current literature

Paediatric myocarditis remains challenging from the perspectives of diagnosis and management. Multiple aetiologies exist and the majority of cases appear to be related to viral illnesses. Enteroviruses are believed to be the most common cause, although cases related to adenovirus may be more frequent than suspected. The clinical presentation is extremely varied, ranging from asymptomatic to sudden unexpected death. A high index of suspicion is crucial. There is emerging evidence to support investigations such as serum N-terminal B-type natriuretic peptide levels, as well as cardiac magnetic resonance imaging as adjuncts to the clinical diagnosis. In the future, these may reduce the necessity for invasive methods, such as endomyocardial biopsy, which remain the gold standard. Management generally includes supportive care, consisting of cardiac failure medical management, with the potential for mechanical support and cardiac transplantation. Treatments aimed at immunosuppression remain controversial. The paediatric literature is extremely limited with no conclusive evidence to support or refute these strategies. This article summarises the current literature regarding aetiology, clinical presentation, diagnosis, and management of myocarditis in paediatric patients.

Non-invasive Investigations for the Diagnosis of Fontan-Associated Liver Disease in Pediatric and Adult Fontan Patients

Fontan-associated liver disease (FALD) is a serious complication related to the chronically elevated venous pressure and low cardiac output of this abnormal circulation. However, diagnostic markers for this condition are limited. We hypothesized that specific tests for fibrosis developed for other chronic liver diseases would identify a higher prevalence of FALD than ultrasound and standard laboratory tests and that identified abnormalities would correlate with time post-Fontan. In this cross-sectional study, we assessed 19 children (average age 8.4 ± 4.3 and 5.4 ± 4.1 years post-Fontan) and 8 adults (average age 31.5 ± 8.9 and 21.1 ± 4 years post-Fontan) using standard serum laboratory investigations assessing hepatic integrity and function, the FibroTest, liver ultrasound, and transient elastography (FibroScan). In adult Fontan patients, hemoglobin, C-reactive protein, and gamma-glutamyl transpeptidase were significantly increased, and white blood cell and platelet counts were significantly decreased in comparison to the pediatric cohort. International normalized ratio was mildly elevated in both children and adults. FibroTest results were suggestive of fibrosis regardless of time post-Fontan. FibroScan measurements were significantly correlated with time post-Fontan, but the incidence of ultrasound-detected liver abnormalities was variable. No cases of hepatocellular carcinoma were identified. Abnormalities suggestive of FALD occur in both children and adults post-Fontan. Select laboratory tests, and possibly ultrasound and FibroScan in some patients, appear to have the most promise for the non-invasive detection of FALD.

Canadian Cardiovascular Society/Canadian Pediatric Cardiology Association Position Statement on Pulse Oximetry Screening in Newborns to Enhance Detection of Critical Congenital Heart Disease

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.

A longitudinal retrospective analysis of left ventricular mass in a cohort of pediatric kidney transplant recipients

Childhood end‐stage kidney disease is associated with increased risk for early adulthood cardiovascular (CV) morbidity and mortality. Increased LVM is an early indicator of CV disease. Previous studies have suggested that LVM decreases after kidney transplantation; however, trends have been inconsistent. A single center retrospective longitudinal cohort analysis of LVM, documented annually, starting before kidney transplantation for up to 10 yr after transplantation was performed. BP documented by annual 24‐h ambulatory monitoring studies, and BMI values were also reviewed. Twenty‐seven children followed for a mean period of 5.3 yr were included. Depending on definition of LVH, its prevalence pretransplant and in the first years post‐transplant was up to 33% dropping to 0–25% thereafter. Individual longitudinal LVM z‐score trends were highly variable but generally trended toward the mean immediately after transplant and toward negative values in the following years. BP was stable during the follow‐up period while mean annual BMI increased in the first‐year post‐transplant but declined thereafter. In a cohort of pediatric renal transplant recipients, prevalence of LVH decreased after transplant; however, individual longitudinal LVM trends were highly variable among patients. Prospective studies are needed to correlate individual LVM trends with outcomes.

Population Trends in Prenatal Detection of Transposition of Great Arteries: Impact of Obstetrical Screening Ultrasound Guidelines

Dextro‐transposition of the great arteries (d‐TGA) is one of the most common critical neonatal heart defects, with a low detection rate antenatally. We sought to evaluate trends in the prenatal detection of d‐TGA with or without ventricular septal defect (VSD) in Alberta over the past 13 years, examining the potential impact of ultrasound guidelines incorporating screening of cardiac outflow tracts, updated in 2009–2010 and in 2013, and factors affecting detection of the condition.

Magnetic resonance imaging of a restrictive atrial septal defect in a univentricular connection.

Magnetic resonance imaging (MRI) provides accurate and valuable information regarding cardiac shunts including their location, size, and flow. We describe the MRI findings of a restrictive atrial septal defect within a complex case of congenital heart disease: univentricular atrioventricular connection of left ventricular type with right-sided discordant atrioventricular connection (single), absent left atrioventricular connection, and ventriculoarterial discordance. Few similar cases are reported in the literature. Magnetic resonance imaging may add valuable information regarding restrictive atrial shunts in univentricular hearts.