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Background: Term newborns with congenital heart disease (CHD) show delayed brain development as early as the third trimester, especially in single-ventricle physiology (SVP). Mechanisms causing delayed brain development in CHD are uncertain but may include

We sought to determine whether childhood obesity is associated with increased aortic stiffness by measuring the biophysical properties of the aorta in obese children using a noninvasive echocardiographic Doppler method. Increased aortic stiffness is a strong predictor of future cardiovascular events and mortality in adults. Obesity is known to be associated with increased aortic stiffness and arterial disease in adults. We prospectively evaluated a cohort of obese children (n = 61) and compared them to normal-weight controls (n = 55). The anthropometric data were recorded. The pulsewave velocity (PWV), aortic input impedance (Zi), characteristic impedance (Zc), arterial pressure-strain elastic modulus (Ep), arterial wall stiffness index (B index), and peak aortic velocity were calculated. We correlated our echocardiographic Doppler findings with the lipid levels. We assessed the left ventricular (LV) dimensions and standard measures of cardiac function. Cardiopulmonary exercise testing was performed on all obese children. Compared to normal-weight children, obese children had a greater PWV, Zc, B index, Ep, and peak aortic velocity. Obese children had greater systolic blood pressure than normal-weight children but no difference in diastolic blood pressure. The LV dimensions and standard measures of cardiac systolic function were similar in the 2 groups, but the obese children had altered diastolic properties. The LV mass was greater in the obese children. No association was found between the lipid levels and the biophysical properties of the aorta. The relative oxygen consumption was 68% predicted in obese children. In conclusion, measures of the biophysical properties of the aorta are already abnormal in obese children, reflecting increased aortic stiffness at this early stage of disease. Obese children also had an increased LV mass, altered diastolic properties, and an abnormal exercise capacity. PWV might be useful in monitoring the progression of arterial disease or the effect of therapeutic interventions. [ABSTRACT FROM AUTHOR]

External auditory canal polyps are most commonly inflammatory in nature but may also manifest more severe disease. Prolonged conservative therapy may delay the correct diagnosis and appropriate intervention. A case is presented of a child with chronic otorrhea treated for 4 months with topical drops and antibiotics. On referral, a large external auditory canal polyp was confirmed to represent a foreign body granuloma covering a large electrical cap, with erosion approaching the facial nerve. External auditory canal polyps that fail to respond promptly to conservative medical therapy warrant a computed tomography scan and surgical exploration with biopsy. [ABSTRACT FROM AUTHOR]

Auditory nerve (AN) function has been hypothesized to deteriorate with age and noise exposure. Here, we perform a systematic review of published studies and find that the evidence for age-related deficits in AN function is largely consistent across the literature, but there are inconsistent findings among studies of noise exposure history. Further, evidence from animal studies suggests that the greatest deficits in AN response amplitudes are found in noise-exposed aged mice, but a test of the interaction between effects of age and noise exposure on AN function has not been conducted in humans. We report a study of our own examining differences in the response amplitude of the compound action potential N1 (CAP N1) between younger and older adults with and without a self-reported history of noise exposure in a large sample of human participants (63 younger adults 18-30 years of age, 103 older adults 50-86 years of age). CAP N1 response amplitudes were smaller in older than younger adults. Noise exposure history did not appear to predict CAP N1 response amplitudes, nor did the effect of noise exposure history interact with age. We then incorporated our results into two meta-analyses of published studies of age and noise exposure history effects on AN response amplitudes in neurotypical human samples. The meta-analyses found that age effects across studies are robust (r = -0.407), but noise exposure effects are weak (r = -0.152). We conclude that noise exposure effects may be highly variable depending on sample characteristics, study design, and statistical approach, and researchers should be cautious when interpreting results. The underlying pathology of age-related and noise-induced changes in AN function are difficult to determine in living humans, creating a need for longitudinal studies of changes in AN function across the lifespan and histological examination of the AN from temporal bones collected post-mortem., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Wearable biosensors (wearables) enable continual, noninvasive physiologic and behavioral monitoring at home for those with pediatric or congenital heart disease. Wearables allow patients to access their personal data and monitor their health. Despite substantial technologic advances in recent years, issues with hardware design, data analysis, and integration into the clinical workflow prevent wearables from reaching their potential in high-risk congenital heart disease populations. This science advisory reviews the use of wearables in patients with congenital heart disease, how to improve these technologies for clinicians and patients, and ethical and regulatory considerations. Challenges related to the use of wearables are common to every clinical setting, but specific topics for consideration in congenital heart disease are highlighted.

Sleep disruptions are a common occurrence during the peripartum period. While physical and environmental factors associated with pregnancy and newborn care account for some sleep disruptions, there is evidence that peripartum fluctuations in estrogens may independently impact sleep. However, the impact of these large fluctuations in estrogens on peripartum sleep is unclear because it is difficult to tease apart the effects of estrogens on sleep from effects associated with the growth and development of the fetus or parental care. We therefore used a hormone-simulated pseudopregnancy (HSP) in female Syrian hamsters to test the hypothesis that pregnancy-like increases in estradiol decrease sleep in the absence of other factors. Adult female Syrian hamsters were ovariectomized and given daily hormone injections that simulate estradiol levels during early pregnancy, late pregnancy, and the postpartum period. Home cage video recordings were captured at seven timepoints and videos were analyzed for actigraphy. During "late pregnancy," total sleep time and sleep efficiency were decreased in hormone-treated animals during the white light period compared to pretest levels. Likewise, during "late pregnancy," locomotion was increased in the white light period for hormone-treated animals compared to pretest levels. These changes continued into the "postpartum period" for animals who continued to receive estradiol treatment, but not for animals who were withdrawn from estradiol. At the conclusion of the experiment, animals were euthanized and cFos expression was quantified in the ventral lateral preoptic area (VLPO) and lateral hypothalamus (LH). Animals who continued to receive high levels of estradiol during the "postpartum" period had significantly more cFos in the VLPO and LH than animals who were withdrawn from hormones or vehicle controls. Together, these data suggest that increased levels of estradiol during pregnancy are associated with sleep suppression, which may be mediated by increased activation of hypothalamic nuclei., (© 2023 British Society for Neuroendocrinology.)

Twenty-four-hour ambulatory blood pressure monitoring (ABPM) is widely accepted as a more accurate method for measurement of blood pressure (BP) compared to a single office-based measurement of BP. However, it is unclear how physicians interpret ABPM and make management decisions. This study's goal is to investigate variation in ABPM interpretation among paediatric nephrologists (Canada and UK) and paediatric cardiologists (Canada only) via an online survey. The survey content included baseline demographics, questions on the use and indications for ABPM, interpretation of results, and subsequent management decisions in various clinical scenarios. The survey was sent to 196 Canadian physicians, with 69 (35.2%) total responses. Thirty-five UK clinicians also completed the survey. Most respondents were >44 years old, were in practice for at least 11 years, and were university-based. There were substantial differences among clinicians in ABPM interpretation for isolated systolic, diastolic, and night-time hypertension. For example, only 53.1% of physicians would initiate or modify treatment in those with diastolic HTN in CKD. Further, even for the same abnormal ABPM parameter, the decision to start or alter treatment was influenced by the underlying medical condition. There is significant variation in clinical practice among physicians for interpretation and management of hypertension when using ABPM. Differences in guidelines among various jurisdictions, as well as knowledge gaps in the research on which guidelines are based, create ambiguity regarding ABPM interpretation and management decisions. A more protocolized approach and further insight into the reasoning behind the variation in physicians' interpretation may help to standardise practice., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

In placental mammals, estradiol levels are chronically elevated during pregnancy, but quickly drop to prepartum levels following birth. This may produce an "estrogen withdrawal" state that has been linked to changes in affective states in humans and rodents during the postpartum period. The neural mechanisms underlying these affective changes, however, are understudied. We used a hormone-simulated pseudopregnancy (HSP), a model of postpartum estrogen withdrawal, in adult female C57BL/6 mice to test the impact of postpartum estradiol withdrawal on several behavioral measures of anxiety and motivation. We found that estradiol withdrawal following HSP increased anxiety-like behavior in the elevated plus maze, but not in the open field or marble burying tests. Although hormone treatment during HSP consistently increased sucrose consumption, sucrose preference was generally not impacted by hormone treatment or subsequent estradiol withdrawal. In the social motivation test, estradiol withdrawal decreased the amount of time spent in proximity to a social stimulus animal. These behavioral changes were accompanied by changes in the expression of ∆FosB, a transcription factor correlated with stable long-term plasticity, in the nucleus accumbens (NAc). Specifically, estrogen-withdrawn females had higher ∆FosB expression in the nucleus accumbens core, but ∆FosB expression did not vary across hormone conditions in the nucleus accumbens shell. Using transgenic reporter mice, we found that this increase in ∆FosB occurred in both D1- and D2-expressing cells in the NAc core. Together, these results suggest that postpartum estrogen withdrawal impacts anxiety and motivation and increases ∆FosB in the NAc core., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Slowed information processing speed is a defining feature of cognitive aging. Nucleus locus coeruleus (LC) and medial prefrontal regions are targets for understanding slowed processing speed because these brain regions influence neural and behavioral response latencies through their roles in optimizing task performance. Although structural measures of medial prefrontal cortex have been consistently related to processing speed, it is unclear if 1) declines in LC structure underlie this association because of reciprocal connections between LC and medial prefrontal cortex, or 2) if LC declines provide a separate explanation for age-related changes in processing speed. LC and medial prefrontal structural measures were predicted to explain age-dependent individual differences in processing speed in a cross-sectional sample of 43 adults (19-79 years; 63% female). Higher turbo-spin echo LC contrast, based on a persistent homology measure, and greater dorsal cingulate cortical thickness were significantly and each uniquely related to faster processing speed. However, only dorsal cingulate cortical thickness appeared to statistically mediate age-related differences in processing speed. The results suggest that individual differences in cognitive processing speed can be attributed, in part, to structural variation in nucleus LC and medial prefrontal cortex, with the latter key to understanding why older adults exhibit slowed processing speed., Competing Interests: Declaration of competing interest The authors declare they have no competing financial interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

There is great interest in developing non-invasive approaches for studying cortical plasticity in humans. High-frequency presentation of auditory and visual stimuli, or sensory tetanisation, can induce long-term-potentiation-like (LTP-like) changes in cortical activity. However, contrasting effects across studies suggest that sensory tetanisation may be unreliable. We review these contrasting effects, conduct our own study of auditory and visual tetanisation, and perform meta-analyses to determine the average effect of sensory tetanisation across studies. We measured auditory-evoked amplitude changes in a group of younger (18-29 years of age) and older (55-83 years of age) adults following tetanisation to 1 and 4 kHz tone bursts and following a slow-presentation control. We also measured visual-evoked amplitude changes following tetanisation to horizontal and vertical sign gradients. Auditory and visual response amplitudes decreased following tetanisation, consistent with some studies but contrasting with others finding amplitude increases (i.e. LTP-like changes). Older adults exhibited more modest auditory-evoked amplitude decreases, but visual-evoked amplitude decreases like those of younger adults. Changes in response amplitude were not specific to tetanised stimuli. Importantly, slow presentation of auditory tone bursts produced response amplitude changes approximating those observed following tetanisation in younger adults. Meta-analyses of visual and auditory tetanisation studies found that the overall effect of sensory tetanisation was not significant across studies or study sites. The results suggest that sensory tetanisation may not produce reliable changes in cortical responses and more work is needed to determine the validity of sensory tetanisation as a method for inducing human cortical plasticity in vivo., (© 2022 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

Dysfunction of the peripheral auditory nerve (AN) contributes to dynamic changes throughout the central auditory system, resulting in abnormal auditory processing, including hypersensitivity. Altered sound sensitivity is frequently observed in autism spectrum disorder (ASD), suggesting that AN deficits and changes in auditory information processing may contribute to ASD-associated symptoms, including social communication deficits and hyperacusis. The MEF2C transcription factor is associated with risk for several neurodevelopmental disorders, and mutations or deletions of MEF2C produce a haploinsufficiency syndrome characterized by ASD, language, and cognitive deficits. A mouse model of this syndromic ASD ( Mef2c -Het) recapitulates many of the MEF2C haploinsufficiency syndrome-linked behaviors, including communication deficits. We show here that Mef2c -Het mice of both sexes exhibit functional impairment of the peripheral AN and a modest reduction in hearing sensitivity. We find that MEF2C is expressed during development in multiple AN and cochlear cell types; and in Mef2c -Het mice, we observe multiple cellular and molecular alterations associated with the AN, including abnormal myelination, neuronal degeneration, neuronal mitochondria dysfunction, and increased macrophage activation and cochlear inflammation. These results reveal the importance of MEF2C function in inner ear development and function and the engagement of immune cells and other non-neuronal cells, which suggests that microglia/macrophages and other non-neuronal cells might contribute, directly or indirectly, to AN dysfunction and ASD-related phenotypes. Finally, our study establishes a comprehensive approach for characterizing AN function at the physiological, cellular, and molecular levels in mice, which can be applied to animal models with a wide range of human auditory processing impairments. SIGNIFICANCE STATEMENT This is the first report of peripheral auditory nerve (AN) impairment in a mouse model of human MEF2C haploinsufficiency syndrome that has well-characterized ASD-related behaviors, including communication deficits, hyperactivity, repetitive behavior, and social deficits. We identify multiple underlying cellular, subcellular, and molecular abnormalities that may contribute to peripheral AN impairment. Our findings also highlight the important roles of immune cells (e.g., cochlear macrophages) and other non-neuronal elements (e.g., glial cells and cells in the stria vascularis) in auditory impairment in ASD. The methodological significance of the study is the establishment of a comprehensive approach for evaluating peripheral AN function and impact of peripheral AN deficits with minimal hearing loss., (Copyright © 2022 the authors.)

Deficits in auditory nerve (AN) function for older adults reduce afferent input to the cortex. The extent to which the cortex in older adults adapts to this loss of afferent input and the mechanisms underlying this adaptation are not well understood. We took a neural systems approach measuring AN and cortical evoked responses within 50 older and 27 younger human adults (59 female) to estimate central gain or increased cortical activity despite reduced AN activity. Relative to younger adults, older adults' AN response amplitudes were smaller, but cortical responses were not. We used the relationship between AN and cortical response amplitudes in younger adults to predict cortical response amplitudes for older adults from their AN responses. Central gain in older adults was thus defined as the difference between their observed cortical responses and those predicted from the parameter estimates of younger adults. In older adults, decreased afferent input contributed to lower cortical GABA levels, greater central gain, and poorer speech recognition in noise (SIN). These effects on SIN occur in addition to, and independent from, effects attributed to elevated hearing thresholds. Our results are consistent with animal models of central gain and suggest that reduced AN afferent input in some older adults may result in changes in cortical encoding and inhibitory neurotransmission, which contribute to reduced SIN. An advancement in our understanding of the changes that occur throughout the auditory system in response to the gradual loss of input with increasing age may provide potential therapeutic targets for intervention. SIGNIFICANCE STATEMENT Age-related hearing loss is one of the most common chronic conditions of aging, yet little is known about how the cortex adapts to this loss of sensory input. We measured AN and cortical responses to the same stimulus in younger and older adults. In older adults we found hyperexcitability in cortical activity relative to concomitant declines in afferent input that are consistent with central gain. Lower levels of cortical GABA, an inhibitory neurotransmitter, were associated with greater central gain, which predicted poorer SIN. The results suggest that the cortex in older adults may adapt to attenuated sensory input by reducing inhibition to amplify the cortical response, but this amplification may lead to poorer SIN., (Copyright © 2022 the authors.)

Atherosclerosis begins in youth and is directly linked with the presence and severity of cardiovascular risk factors, including dyslipidemia. Thus, the timely identification and management of dyslipidemia in childhood might slow atherosclerotic progression and decrease the risk of cardiovascular disease in adulthood. This is particularly true for children with genetic disorders resulting in marked dyslipidemia, including familial hypercholesterolemia, which remains frequently undiagnosed. Universal and cascade screening strategies can effectively identify cases of pediatric dyslipidemia. In the clinical evaluation of children with dyslipidemia, evaluating for secondary causes of dyslipidemia, including medications and systemic disorders is essential. The first line therapy generally centres around lifestyle modifications, with dietary changes specific to the dyslipidemia phenotype. Indications for medication depend on the severity of dyslipidemia and an individualized assessment of cardiovascular risk. Despite an expanding evidence base supporting the detection and timely management of pediatric dyslipidemia, numerous knowledge gaps remain, including a sufficient evidence base to support more widespread screening, thresholds for initiation of pharmacotherapy, and treatment targets. Further studies on the most appropriate age for statin initiation and long-term safety studies of statin use in youth are also required. The most pressing matter, however, is the development of knowledge translation strategies to improve the screening and detection of lipid disorders in Canadian youth., (Copyright © 2022 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Aging is associated with auditory nerve (AN) functional deficits and decreased inhibition in the central auditory system, amplifying central responses in a process referred to here as central gain. Although central gain increases response amplitudes, central gain may not restore disrupted response timing. In this translational study, we measured responses putatively generated by the AN and auditory midbrain in younger and older mice and humans. We hypothesized that older mice and humans exhibit increased central gain without an improvement in inter-trial synchrony in the midbrain. Our data demonstrated greater age-related deficits in AN response amplitudes than auditory midbrain response amplitudes, as shown by significant interactions between inferred neural generator and age group, indicating increased central gain in auditory midbrain. However, synchrony decreases with age in both the AN and midbrain responses. These results reveal age-related increases in central gain without concomitant improvements in synchrony, consistent with those predictions based on decreases in inhibition. Persistent decreases in synchrony may contribute to auditory processing deficits in older mice and humans., (Published by Elsevier Inc.)

Over time, long-term survival has dramatically increased for patients with complex congenital heart disease who undergo the Fontan operation. With this increased survival, it has become apparent that such a circulation has important consequences for other organ systems, particularly the liver and kidney. The adverse milieu created by chronic venous hypertension, low cardiac output, and an inflammatory state contribute to the pathologic changes observed in the liver and kidneys over the long term in Fontan patients. The clinical importance of these hepatic and renal comorbidities have only recently begun to be recognized in the context of increasing life expectancy in this population. The objectives of this review are to provide an overview of the pathophysiology of the Fontan circulation and how liver and kidney disease evolve in this setting; to summarize the current evidence base as it relates to the diagnostic approach to liver and kidney disease in Fontan patients; and to discuss the therapeutic approaches to Fontan- associated liver and kidney disease. Given that this is a very active area of research in congenital heart disease, we have identified knowledge gaps and priority research areas to improve the care of Fontan patients. These include establishing the optimal diagnostic tests to detect and track liver and kidney disease change over time, determining which treatable risk factors contribute to the development of liver and kidney disease, and evaluating therapies to prevent or slow progression of liver and kidney disease., (Copyright © 2022 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Background: Coronavirus disease 2019 (COVID-19) was associated with a reduction in physical activity in children with congenital heart disease (CHD) in early 2020. Given the increased cardiovascular risk of this population, optimizing cardiovascular health behaviour is important. The aim of the study is to determine how the ongoing COVID-19 pandemic has impacted longitudinal physical activity measures in children with CHD., Methods: As part of a prospective cohort study, children and adolescents aged 9-16 years old with moderate-to-complex CHD were recruited from British Columbia Children's Hospital and partnership clinics across British Columbia and the Yukon territory. Daily step counts were measured continuously over 3 years (2018-2021) with Fitbit Charge 2. School status during the COVID-19 pandemic was assessed with parent- or self-report survey., Results: A total of 102, 114, and 93 participants had valid Fitbit data during 2018, 2019, and 2020, respectively. There was a significant reduction in the annual mean step count for 2020 (8225 ± 4328 steps) compared with both 2018 (9416 ± 3770 steps) and 2019 (9533 ± 4114 steps) ( P < 0.001). There was a loss of seasonal variation in physical activity, and reduced levels of physical activity persisted when most children resumed in-person schooling in September 2020., Conclusions: We demonstrated a significant decrease in physical activity and loss of seasonal patterns in children with CHD during 2020. These findings represent a worsening of the cardiovascular risk profile in children with CHD, who are already at an increased risk of adverse cardiovascular outcomes. Mitigation strategies are needed to optimize the cardiovascular health status of children with CHD as the pandemic persists., (© 2022 Published by Elsevier Inc. on behalf of the Canadian Cardiovascular Society.)

A bidirectional comorbidity exists between depression and epilepsy such that patients with epilepsy are at higher risk for developing depression, and vice versa. Each of these conditions individually can be complicated by behavioral effects that worsen quality of life, but less is known about these interactions within the comorbidity of depression and epilepsy. The SwLo rat has been selectively bred for depression-relevant behaviors and exhibits enhanced limbic seizure susceptibility. This study sought to characterize the effects of novelty and stress on the SwLo rodent model of this comorbidity. It was hypothesized that SwLo rats would exhibit altered responses to novelty, reflected in hyperactivity-, anxiety-, sensation seeking-, and/or compulsive behaviors, and that this would be exacerbated with stress. Compared to the SwHi rat (their depression- and epilepsy-resistant counterparts), SwLo rats showed increased entries in all areas of the Open Field Test and spent significantly more time in the light compartment of the Light-Dark Box. SwLo rats also had a significantly higher number of rearing behaviors in the inner squares of the Open Field Test, the closed arms of the Elevated Plus Maze, and both areas of the Light-Dark Box. They demonstrated increased Nestlet shredding but showed no difference in a marble burying task or in latency to consume food in a novelty suppressed feeding task. Interestingly, restraint stress showed little effect on these behaviors, despite increasing corticosterone levels. Combined, these results suggest an increase in exploratory sensation seeking and hypervigilant information-gathering behaviors in the SwLo rat that are not dependent on corticosterone levels. This shows the utility of this model for studying behavioral effects of comorbid depression and epilepsy and allows for their use in identifying underlying mechanisms or screening treatment strategies for this complex comorbidity., (Copyright © 2022. Published by Elsevier Inc.)

The auditory nerve (AN) of the inner ear is the primary conveyor of acoustic information from sensory hair cells to the brainstem. Approximately 95% of peripheral AN fibers are myelinated by glial cells. The integrity of myelin and the glial-associated paranodal structures at the node of Ranvier is critical for normal AN activity and axonal survival and function in the central auditory nervous system. However, little is known about the node of Ranvier's spatiotemporal development in the AN, how the aging process (or injury) affects the activity of myelinating glial cells, and how downstream alterations in myelin and paranodal structure contribute to AN degeneration and sensorineural hearing loss. Here, we characterized two types of Ranvier nodes-the axonal node and the ganglion node-in the mouse peripheral AN, and found that they are distinct in several features of postnatal myelination and age-related degeneration. Cellular, molecular, and structure-function correlations revealed that the two node types are each critical for different aspects of peripheral AN function. Neural processing speed and synchrony is associated with the length of the axonal node, while stimulus level-dependent amplitude growth and action potentials are associated with the ganglion node. Moreover, our data indicate that dysregulation of glial cells (e.g., satellite cells) and degeneration of the ganglion node structure are an important new mechanism of age-related hearing loss., (© 2021 Wiley Periodicals LLC.)

Accumulating evidence suggests that cochlear deafferentation may contribute to suprathreshold deficits observed with or without elevated hearing thresholds, and can lead to accelerated age-related hearing loss. Currently there are no clinical diagnostic tools to detect human cochlear deafferentation in vivo. Preclinical studies using a combination of electrophysiological and post-mortem histological methods clearly demonstrate cochlear deafferentation including myelination loss, mitochondrial damages in spiral ganglion neurons (SGNs), and synaptic loss between inner hair cells and SGNs. Since clinical diagnosis of human cochlear deafferentation cannot include post-mortem histological quantification, various attempts based on functional measurements have been made to detect cochlear deafferentation. So far, those efforts have led to inconclusive results. Two major obstacles to the development of in vivo clinical diagnostics include a lack of standardized methods to validate new approaches and characterize the normative range of repeated measurements. In this overview, we examine strategies from previous studies to detect cochlear deafferentation from electrocochleography and auditory brainstem responses. We then summarize possible approaches to improve these non-invasive functional methods for detecting cochlear deafferentation with a focus on cochlear synaptopathy. We identify conceptual approaches that should be tested to associate unique electrophysiological features with cochlear deafferentation.

Auditory function declines with age, as evidenced by communication difficulties in challenging listening environments for older adults. Declining auditory function may arise, in part, from an age-related loss and/or inactivity of low-spontaneous-rate (SR) auditory nerve (AN) fibers, a subgroup of neurons important for suprathreshold processing. Compared to high-SR fibers, low-SR fibers take longer to recover from prior stimulation. Taking advantage of this difference, the forward-masked recovery function paradigm estimates the relative proportions of low- and high-SR fibers in the AN by quantifying the time needed for AN responses to recover from prior stimulation (ΔT recovery ). Due to the slower recovery of low-SR fibers, ANs that need more time to fully recover (longer ΔT recovery ) are estimated to have a larger proportion of low-SR fibers than ANs that need less time (shorter ΔT recovery ). To test the hypothesis that low-SR fiber activity is reduced in older humans, the current study assessed recovery functions in 32 older and 16 younger adults using the compound action potential. Results show that ΔT recovery is shorter for older adults than for younger adults, consistent with a theorized age-related loss and/or inactivity of low-SR fibers. ΔT recovery did not differ between individuals with and without a prior history of noise exposure as assessed by self-report. This study is the first to successfully assess forward-masked recovery functions in both younger and older adults and provides important insights into the structural and functional changes occurring in the AN with increasing age., (© 2022. The Author(s) under exclusive licence to Association for Research in Otolaryngology.)

Background: Physical activity (PA) is important for cardiovascular health as well as social and emotional well-being of children. Patients with long QT syndrome (LQTS) often face PA restrictions and are often prescribed beta-blockers for disease management. The aim of this study was to determine if PA levels were lower in patients with LQTS compared with healthy controls., Methods: Participants with LQTS from an inherited arrhythmia clinic completed the Physical Activity Questionnaire for Children and Adolescents (PAQ-C/A) and an exercise stress test. PAQ score (a general measure of PA for youth, unitless) and endurance time were compared with healthy controls., Results: Twenty-three patients with LQTS completed the PAQ and had an exercise stress test within a year of having completed the PAQ. No difference was observed in PAQ scores between LQTS and control groups (LQTS: 2.3 ± 0.15 vs controls: 2.3 ± 0.18; P  = 0.78). There was no effect of age on PA in patients with LQTS ( P > 0.05), whereas PA significantly decreased in controls with age (eg, 11-12 vs 17-20 years: 3.2 ± 0.07 vs 1.5 ± 0.08, P  = 0.005). Endurance time and heart rate at peak exercise were significantly lower in patients with LQTS compared with controls (11 ± 0.5 vs 15 ± 0.5 minutes, P < 0.0001; 169 ± 5 vs 198 ± 2 beats per minute, P < 0.0001)., Conclusions: Despite guideline recommendations restricting PA, risk of sudden cardiac death, and use of beta-blockers, our cohort of patients with LQTS reported similar PA levels as healthy controls., (© 2021 The Authors.)

Background: Congenital heart disease, the most common congenital anomaly, often presents in neonates. Because of perceived risks, health care providers may consider deferring immunizations in this population. We sought to understand the perceived risk of immunizations in those providing health care to children with particular heart conditions., Methods: A survey, which included 6 hypothetical scenarios assessing immunization recommendations, was distributed internationally to relevant health care providers, and responses were compared between the different scenarios., Results: Majority of responses (n = 142) were from paediatric cardiologists (n = 98; 69%) and nurse practitioners (n = 27; 19%) located in the United States (n = 77; 54%) or Canada (n = 53; 37%) working in academic teaching hospitals (n = 133; 93.7%). Most favoured vaccinations (n = 107; 75.4%) and less likely to proceed with the first immunization in infants with structural heart disease compared with channelopathy (risk ratio: 0.80, confidence interval: 0.73-0.87; P  < 0.001). Only 40% would proceed with immunization as normal in an infant with manifest Brugada type I electrocardiogram. Special precautions after the immunization included longer duration of observation (19%) and administering prophylactic antipyretic medication (92%)., Conclusions: Respondents were 20% more likely to defer immunizations in the presence of treatable structural heart disease as compared with channelopathy despite the lack of evidence supporting deferring immunizations in children with structural heart disease. Most were cautious in their response to the scenario involving Brugada syndrome, indicating awareness of the risk of haemodynamic instability in the event of a fever. The majority of respondents still strongly recommend immunizations in this population as the benefits outweigh the potential for adverse events., (© 2022 The Author(s).)

Thrombosis remains an important complication for children with single-ventricle physiology following the Fontan procedure, and effective thromboprophylaxis is an important unmet medical need. To obviate conventional dose-finding studies and expedite clinical development, a rivaroxaban dose regimen for this indication was determined using a model-informed drug development approach. A physiologically based pharmacokinetic rivaroxaban model was used to predict a pediatric dosing regimen that would produce drug exposures similar to that of 10 mg once daily in adults. This regimen was used in an open-label, multicenter phase III study, which investigated the use of rivaroxaban for thromboprophylaxis in post-Fontan patients 2 to 8 years of age. The pharmacokinetics (PK) of rivaroxaban was assessed in part A (n = 12) and in part B (n = 64) of the UNIVERSE study. The safety and efficacy in the rivaroxaban group were compared to those in the acetylsalicylic acid group for 12 months. Pharmacodynamic end points were assessed in both parts of the study. Rivaroxaban exposures achieved in parts A and B were similar to the adult reference exposures. Prothrombin time also showed similarity to the adult reference. Exposure-response analysis did not identify a quantitative relationship between rivaroxaban exposures and efficacy/safety outcomes within the observed exposure ranges. A body weight-based dose regimen selected by physiologically based pharmacokinetic modeling was shown in the UNIVERSE study to be appropriate for thromboprophylaxis in the post-Fontan pediatric population. Model-based dose selection can support pediatric drug development and bridge adult dose data to pediatrics, thereby obviating the need for dose-finding studies in pediatric programs., (© 2021 Janssen Research and Development LLC. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Background: Cardiac allograft vasculopathy, the leading cause of graft failure in pediatric heart transplant recipients, is characterized by diffuse and concentric coronary intimal thickening. Early treatment yields better outcomes. While coronary angiography is the standard for cardiac allograft vasculopathy screening and diagnosis, it only identifies luminal narrowing, which occurs in more severe disease. Coronary optical coherence tomography (OCT) is a high-definition intravascular imaging modality that may offer earlier diagnosis. We used OCT to investigate coronary intimal thickening in pediatric transplant recipients and examined its (1) location (ie, vessel type and location) and (2) nature (ie, characteristics of cross-sectional and longitudinal thickening)., Methods: Sites collected coronary angiography and OCT data from participants (N=258 vessel segments from 73 individuals; median age: 11.5 years [8.4-15.3]; 55% male). Images were collected from the left anterior descending, left circumflex, and right coronary arteries, and location (ie, proximal, middle, and distal) were classified using coronary angiography., Results: OCT identified 32 vessel segments meeting criteria for significant thickening, 88% of which were angiographically silent. Longitudinal thickening was segmental rather than global in 88%, and cross-sectional thickening was 48% eccentric and 52% concentric. Intimal thickening prevalence and severity measures did not consistently differ between coronary artery type ( P =1.000) or location ( P =0.248) but increased with time since transplant and age at transplant and OCT procedure., Conclusions: In pediatric transplant recipients, we observed a surprisingly high prevalence of segmental and eccentric intimal thickening. Insights from intravascular imaging suggest these patterns of coronary vascular changes may precede overt cardiac allograft vasculopathy. Identifying early changes may offer opportunity for enhanced surveillance and earlier intervention.

A common complaint of older adults is difficulty understanding speech, particularly in challenging listening conditions. Accumulating evidence suggests that these difficulties may reflect a loss and/or dysfunction of auditory nerve (AN) fibers. We used a novel approach to study age-related changes in AN structure and several measures of AN function, including neural synchrony, in 58 older adults and 42 younger adults. AN activity was measured in response to an auditory click (compound action potential; CAP), presented at stimulus levels ranging from 70 to 110 dB pSPL. Poorer AN function was observed for older than younger adults across CAP measures at higher but not lower stimulus levels. Associations across metrics and stimulus levels were consistent with age-related AN disengagement and AN dyssynchrony. High-resolution T2-weighted structural imaging revealed age-related differences in the density of cranial nerve VIII, with lower density in older adults with poorer neural synchrony. Individual differences in neural synchrony were the strongest predictor of speech recognition, such that poorer synchrony predicted poorer recognition of time-compressed speech and poorer speech recognition in noise for both younger and older adults. These results have broad clinical implications and are consistent with an interpretation that age-related atrophy at the level of the AN contributes to poorer neural synchrony and may explain some of the perceptual difficulties of older adults. SIGNIFICANCE STATEMENT Differences in auditory nerve (AN) pathophysiology may contribute to the large variations in hearing and communication abilities of older adults. However, current diagnostics focus largely on the increase in detection thresholds, which is likely because of the absence of indirect measures of AN function in standard clinical test batteries. Using novel metrics of AN function, combined with estimates of AN structure and auditory function, we identified age-related differences across measures that we interpret to represent age-related reductions in AN engagement and poorer neural synchrony. Structure-function associations are consistent with an explanation of AN deficits that arise from age-related atrophy of the AN. Associations between neural synchrony and speech recognition suggest that individual and age-related deficits in neural synchrony contribute to speech recognition deficits., (Copyright © 2021 the authors.)

Background Patients with single-ventricle physiology who undergo the Fontan procedure are at risk for thrombotic events associated with significant morbidity and mortality. The UNIVERSE Study evaluated the efficacy and safety of a novel liquid rivaroxaban formulation, using a body weight-adjusted dosing regimen, versus acetylsalicylic acid (ASA) in children post-Fontan. Methods and Results The UNIVERSE Study was a randomized, multicenter, 2-part, open-label study of rivaroxaban, in children who had undergone a Fontan procedure, to evaluate its dosing regimen, safety, and efficacy. Part A was the single-arm part of the study that determined the pharmacokinetics/pharmacodynamics and safety of rivaroxaban in 12 participants before proceeding to part B, whereby 100 participants were randomized 2:1 to open-label rivaroxaban versus ASA. The study period was 12 months. A total of 112 participants were enrolled across 35 sites in 10 countries. In part B, for safety outcomes, major bleeding occurred in one participant on rivaroxaban (epistaxis that required transfusion). Clinically relevant nonmajor bleeding occurred in 6% of participants on rivaroxaban versus 9% on ASA. Trivial bleeding occurred in 33% of participants on rivaroxaban versus 35% on ASA. For efficacy outcomes, 1 participant on rivaroxaban in part B had a pulmonary embolism (2% overall event rate); and for ASA, 1 participant had ischemic stroke and 2 had venous thrombosis (9% overall event rate). Conclusions In this study, participants who received rivaroxaban for thromboprophylaxis had a similar safety profile and fewer thrombotic events, albeit not statistically significant, compared with those in the ASA group. Registration URL: https://www.clinicaltrials.gov. Identifier: NCT02846532.

Background Diuretics are used to manage congestive heart failure in infants with congenital heart disease. Adult data indicate that preoperative diuretic use increases the risk of cardiac surgery associated acute kidney injury (CS-AKI). We have sought to understand if preoperative diuretics in infants increases the risk of CS-AKI. Methods and Results This is a single-center retrospective study of infants (1-12 months) who had CS requiring cardiopulmonary bypass between 2013 and 2018. The diagnosis and severity of CS-AKI was defined according to the Kidney Disease Improving Global Outcomes guidelines. Three hundred patients were included (mean 6 months, SD 2.4, range 1.2-12.9 months). A total of 149 (49.7%) patients were diagnosed with CS-AKI (stage 1: 80 [54%], stage 2: 57 [38%], stage 3: 12 [8%]). Logistic regression analysis showed preoperative diuretics were not associated with CS-AKI (odds ratio [OR], 0.79; 95% CI, 0.43-1.44; P =0.45). A diagnosis of tetralogy of Fallot was an independent risk factor for CS-AKI (OR, 3.49; 95% CI, 1.33-9.1, P =0.01). A diagnosis of tetralogy of Fallot (OR, 3.6; 95% CI, 1.28-10.22; P =0.02) and longer cardiopulmonary bypass (OR, 1.01; 95% CI, 1.0-1.02; P =0.04) time are risk factors for moderate to severe CS-AKI. Conclusions Preoperative diuretic use does not contribute to the risk of CS-AKI in infants early after surgery. A diagnosis of tetralogy of Fallot was the only risk factor for CS-AKI identified using multivariate analysis in our cohort. Furthermore, a diagnosis of tetralogy of Fallot and longer cardiopulmonary bypass time are risk factors for moderate to severe CS-AKI.

Individuals typically exhibit better cross-sensory perception following unisensory loss, demonstrating improved perception of information available from the remaining senses and increased cross-sensory use of neural resources. Even individuals with no sensory loss will exhibit such changes in cross-sensory processing following temporary sensory deprivation, suggesting that the brain's capacity for recruiting cross-sensory sources to compensate for degraded unisensory input is a general characteristic of the perceptual process. Many studies have investigated how auditory and visual neural structures respond to within- and cross-sensory input. However, little attention has been given to how general auditory and visual neural processing relates to within and cross-sensory perception. The current investigation examines the extent to which individual differences in general auditory neural processing accounts for variability in auditory, visual, and audiovisual speech perception in a sample of young healthy adults. Auditory neural processing was assessed using a simple click stimulus. We found that individuals with a smaller P1 peak amplitude in their auditory-evoked potential (AEP) had more difficulty identifying speech sounds in difficult listening conditions, but were better lipreaders. The results suggest that individual differences in the auditory neural processing of healthy adults can account for variability in the perception of information available from the auditory and visual modalities, similar to the cross-sensory perceptual compensation observed in individuals with sensory loss., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Pediatric cardiology has evolved over time with reductions in childhood mortality due to congenital heart disease. Surgical innovation drove early changes in care. Increasingly, the need for more robust evidence provided by randomised controlled trials (RCTs) has been recognised. Although the number of RCTs has increased, there remains a relative paucity of truly impactful trials in the field. However, those trials that have changed practice have demonstrated the potential and importance of this work. Examples include the PRIMACORP trial, which established the safety and efficacy of milrinone after cardiac surgery, and the Single Ventricle Reconstruction trial, which was the first multicentre pediatric cardiac surgical RCT. The successful conduct and important findings emanating from these trials serve as beacons as clinicians strive to improve the evidence base in this field. The establishment of national and international networks such as the Pediatric Heart Network and the Canadian Pediatric Cardiology Research Network provide a strong foundation for future collaborative work. Despite this progress, there remain important challenges to designing and executing RCTs in pediatric cardiology. These include issues of greater disease and patient heterogeneity and increased costs. The use of innovative study designs and analytic methods and the establishment of core outcome measures have the potential to overcome some of the issues related to the smaller patient numbers compared with adult disciplines. As pediatric cardiologists look to the future, it is imperative that we work together to derive the maximum benefit from the considerable efforts directed toward conducting impactful clinical trials in pediatric cardiology., (Copyright © 2021 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Multisensory input can improve perception of ambiguous unisensory information. For example, speech heard in noise can be more accurately identified when listeners see a speaker's articulating face. Importantly, these multisensory effects can be superadditive to listeners' ability to process unisensory speech, such that audiovisual speech identification is better than the sum of auditory-only and visual-only speech identification. Age-related declines in auditory and visual speech perception have been hypothesized to be concomitant with stronger cross-sensory influences on audiovisual speech identification, but little evidence exists to support this. Currently, studies do not account for the multisensory superadditive benefit of auditory-visual input in their metrics of the auditory or visual influence on audiovisual speech perception. Here we treat multisensory superadditivity as independent from unisensory auditory and visual processing. In the current investigation, older and younger adults identified auditory, visual, and audiovisual speech in noisy listening conditions. Performance across these conditions was used to compute conventional metrics of the auditory and visual influence on audiovisual speech identification and a metric of auditory-visual superadditivity. Consistent with past work, auditory and visual speech identification declined with age, audiovisual speech identification was preserved, and no age-related differences in the auditory or visual influence on audiovisual speech identification were observed. However, we found that auditory-visual superadditivity improved with age. The novel findings suggest that multisensory superadditivity is independent of unisensory processing. As auditory and visual speech identification decline with age, compensatory changes in multisensory superadditivity may preserve audiovisual speech identification in older adults. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

There are multiple etiologies and phenotypes of age-related hearing loss or presbyacusis. In this review we summarize findings from animal and human studies of presbyacusis, including those that provide the theoretical framework for distinct metabolic, sensory, and neural presbyacusis phenotypes. A key finding in quiet-aged animals is a decline in the endocochlear potential (EP) that results in elevated pure-tone thresholds across frequencies with greater losses at higher frequencies. In contrast, sensory presbyacusis appears to derive, in part, from acute and cumulative effects on hair cells of a lifetime of environmental exposures (e.g., noise), which often result in pronounced high frequency hearing loss. These patterns of hearing loss in animals are recognizable in the human audiogram and can be classified into metabolic and sensory presbyacusis phenotypes, as well as a mixed metabolic+sensory phenotype. However, the audiogram does not fully characterize age-related changes in auditory function. Along with the effects of peripheral auditory system declines on the auditory nerve, primary degeneration in the spiral ganglion also appears to contribute to central auditory system aging. These inner ear alterations often correlate with structural and functional changes throughout the central nervous system and may explain suprathreshold speech communication difficulties in older adults with hearing loss. Throughout this review we highlight potential methods and research directions, with the goal of advancing our understanding, prevention, diagnosis, and treatment of presbyacusis., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020. Published by Elsevier B.V.)

Background: Aortic dilation, stiffening, and dissection are common and potentially lethal complications of Marfan syndrome (MFS) and Loeys-Dietz syndrome (LDS), which involve abnormal transforming growth factor beta (TGF-β) signalling. The relation of aortic dimensions, stiffness, and biomarker levels is unknown. The objective of this study was to measure aortic dimensions, stiffness, TGF-β and matrix metalloproteinase (MMP) levels, and endothelial function in patients with MFS, and to compare TGF-β levels in patients with MFS receiving different therapeutic regimens., Methods: This was a cohort study of 40 MFS and 4 LDS patients and 87 control participants. Aortic dimension and stiffness indexes, including pulse wave velocity (PWV), were measured using echocardiography and Doppler. Total and free TGF-β and MMP blood levels were measured using Quantikine (R&D Systems, Inc, Minneapolis, MN) and Quanterix (Billerica, MA) kits. Endothelial function was measured using brachial artery flow-mediated dilation., Results: PWV was increased in patients with MFS. There were increased MMP-2 levels in those with MFS but no increase in free or total TGF-β or MMP-9 levels compared with control participants. There was no difference in TGF-β levels between MFS patients receiving no medications, angiotensin receptor blockers, and β-blockers. PWV correlated most strongly with age. Endothelial function showed premature gradual decline in patients with MFS., Conclusions: Despite the increased PWV, monitoring aortic stiffness or TGF-β levels would not be helpful in patients with MFS. TGF-β levels were not increased and the increased MMP-2 levels suggest consideration of a different therapeutic target., (© 2021 The Authors.)

Background: The auditory brainstem response (ABR), specifically wave I, is widely used to noninvasively measure auditory nerve (AN) function. Recent work in humans has introduced novel electrocochleographic measures to comprehensively characterize AN function that emphasize suprathreshold processing and estimate neural synchrony., New Method: This study establishes new tools for evaluating AN function in vivo in adult mice using tone-evoked ABRs obtained from young-adult CBA/CaJ mice, adapting the approach previously introduced in humans. Six metrics are obtained from ABR wave I at suprathreshold stimulus levels., Results: Change-point analyses show that the metrics' rate of change with stimulus level differs between moderate and high suprathreshold levels, suggesting that this approach can potentially characterize the presence of heterogeneous AN fiber types., Comparison With Existing Methods: Traditional ABR approaches focus on response thresholds and averaged amplitudes/latencies. In contrast, our multi-metric approach, which uses single-trial data and suprathreshold stimuli, provides novel information and identifies evidence of neural synchrony deficits and changes in the heterogeneity of AN fibers underlying AN behavior., Conclusion: The techniques reported here provide a novel tool to assess changes in AN function in vivo in a commonly used animal model. A benchmark of most current hearing research is the transition from animal to human studies. Here we established a translational objective approach, applying methods that were first developed in humans to animals. This approach enables researchers to identify changes in AN function arising from the animal models with well-characterized pathology, and predict similar pathological changes in human AN dysfunction and hearing loss., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: We sought to identify seasonal variation in physical activity that different physical activity measurement tools can capture in children with congenital heart disease., Methods: Data were collected as part of a prospective cohort study at BC Children's Hospital, Vancouver, Canada. Daily step counts of children aged 9-16 years with moderate-to-severe CHD were assessed continuously for 1-year via a commercial activity tracker (Fitbit Charge 2™). Physical activity levels were also assessed conventionally at one time-point via accelerometers (ActiGraph) and physical activity questionnaires., Results: 156 children (mean age 12.7±2.4 years; 42% female) participated in the study. Fitbit data (n = 96) over a 1-year period clearly illustrated seasonal peaks (late spring and autumn) and dips (winter and summer school holidays) in physical activity levels, with group mean values being below 12,000 steps per day throughout the year. According to conventional accelerometry data (n = 142), 26% met guidelines, which tended to differ according to season of measurement (spring: 39%, summer: 11%, fall: 20%, winter: 39%; p-value = 0.053). Questionnaire data (n = 134) identified that the most widely reported activities were walking (81%) and running (78%) with walking being the highest in summer and fall and running in winter and spring. Furthermore, regardless of overall activity levels the children exhibit similar seasonal variation., Conclusions: We demonstrated that physical activity level changes across seasons in children with CHD. It is important to be aware of these fluctuations when assessing and interpreting physical activity levels. Season specific counselling for physical activity may be beneficial in a clinical setting., Competing Interests: The authors have declared that no competing interests exist.