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BACKGROUND: There is growing recognition that COVID-19 does cause cardiac sequelae. The underlying mechanisms involved are still poorly understood to date. Viral infections, including COVID-19, have been hypothesized to contribute to autoimmunity, by exposing previously hidden cryptic epitopes on damaged cells to an activated immune system. Given the high incidence of cardiac involvement seen in COVID-19, our aim was to determine the frequency of anti-DSG2 antibodies in a population of post COVID-19 patients. METHODS AND RESULTS: 300 convalescent serum samples were obtained from a group of post COVID-19 infected patients from October 2020 to February 2021. 154 samples were drawn 6 months post-COVID-19 infection and 146 samples were drawn 9 months post COVID infection. 17 samples were obtained from the same patient at the 6- and 9- month mark. An electrochemiluminescent-based immunoassay utilizing the extracellular domain of DSG2 for antibody capture was used. The mean signal intensity of anti-DSG2 antibodies in the post COVID-19 samples was significantly higher than that of a healthy control population (19 ± 83.2 in the post-COVID-19 sample vs. 2.1 ± 7.2 (p < 0. 0001) in the negative control healthy population). Of note, 29.3% of the post COVID-19 infection samples demonstrated a signal higher than the 90th percentile of the control population and 8.7% were higher than the median found in ARVC patients. The signal intensity between the 6-month and 9-month samples did not differ significantly. CONCLUSIONS: We report for the first time that recovered COVID-19 patients demonstrate significantly higher and sustained levels of anti-DSG2 autoantibodies as compared to a healthy control population, comparable to that of a diagnosed ARVC group.
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COVID-19 , Autoanticuerpos/inmunología , COVID-19/sangre , COVID-19/complicaciones , COVID-19/inmunología , Desmogleína 2/inmunología , Humanos , Síndrome Post Agudo de COVID-19RESUMEN
BACKGROUND: Introduction to a multi-professional team who are working and caring for the dying, and facing complex moral and ethical dilemmas during Oncology and Palliative Medicine postings influence a medical student's professional identity formation (PIF). However, limited appreciation of PIF, inadequate assessments and insufficient support jeopardise this opportunity to shape how medical students think, feel and act as future physicians. To address this gap, a systematic scoping review (SSR) of PIF assessment methods is proposed. METHODS: A Systematic Evidence-based Approach (SEBA) guided SSR of assessments of PIF in medical schools published between 1st January 2000 and 31st December 2021 in PubMed, Embase, ERIC and Scopus databases was carried out. Included articles were concurrently content and thematically analysed using SEBA's Split Approach and the themes and categories identified were combined using SEBA's Jigsaw Perspective. The review hinged on the following questions: "what is known about the assessment of professional identity formation amongst medical students?", "what are the theories and principles guiding the assessment of professional identity formation amongst medical students?", "what factors influence PIF in medical students?", "what are the tools used to assess PIF in medical students?", and "what considerations impact the implementation of PIF assessment tools amongst medical students?". RESULTS: Two thousand four hundred thirty six abstracts were reviewed, 602 full-text articles were evaluated, and 88 articles were included. The 3 domains identified were 1) theories, 2) assessment, and 3) implementation in assessing PIF. Differing attention to the different aspects of the PIF process impairs evaluations, jeopardise timely and appropriate support of medical students and hinder effective implementation of PIF assessments. CONCLUSION: The Krishna-Pisupati model combines current theories and concepts of PIF to provide a more holistic perspective of the PIF process. Under the aegis of this model, Palliative Care and Oncology postings are envisaged as Communities of Practice influencing self-concepts of personhood and identity and shaping how medical students see their roles and responsibilities as future physicians. These insights allow the forwarding of nine recommendations to improve assessments of PIF and shape the design of a PIF-specific tool that can direct timely and personalized support of medical students.
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Medicina Paliativa , Médicos , Estudiantes de Medicina , Humanos , Identificación Social , AutoimagenRESUMEN
The Common Model of Cognition (CMC) is a recently proposed, consensus architecture intended to capture decades of progress in cognitive science on modeling human and human-like intelligence. Because of the broad agreement around it and preliminary mappings of its components to specific brain areas, we hypothesized that the CMC could be a candidate model of the large-scale functional architecture of the human brain. To test this hypothesis, we analyzed functional MRI data from 200 participants and seven different tasks that cover a broad range of cognitive domains. The CMC components were identified with functionally homologous brain regions through canonical fMRI analysis, and their communication pathways were translated into predicted patterns of effective connectivity between regions. The resulting dynamic linear model was implemented and fitted using Dynamic Causal Modeling, and compared against six alternative brain architectures that had been previously proposed in the field of neuroscience (three hierarchical architectures and three hub-and-spoke architectures) using a Bayesian approach. The results show that, in all cases, the CMC vastly outperforms all other architectures, both within each domain and across all tasks. These findings suggest that a common set of architectural principles that could be used for artificial intelligence also underpins human brain function across multiple cognitive domains.
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Inteligencia Artificial , Encéfalo/fisiología , Cognición/fisiología , Conectoma , Inteligencia/fisiología , Teorema de Bayes , Humanos , Imagen por Resonancia Magnética , Red Nerviosa/fisiologíaRESUMEN
It remains poorly resolved when and how motor cortical output directly influences limb muscle activity through descending projections, which impedes mechanistic understanding of cortical movement control. Here we addressed this in mice performing an ethologically inspired all-limb climbing behavior. We quantified the direct influence of forelimb primary motor cortex (caudal forelimb area, CFA) on muscle activity comprehensively across the muscle activity states that occur during climbing. We found that CFA informs muscle activity pattern, mainly by selectively activating certain muscles while exerting much smaller, bidirectional effects on their antagonists. From Neuropixel recordings, we identified linear combinations (components) of motor cortical activity that covary with these effects, finding that these components differ from those that covary with muscle activity or kinematics. Collectively, our results reveal an instructive direct motor cortical influence on limb muscles that is selective within a motor behavior and reliant on a new type of neural activity subspace.
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Preclinical models (typically ovariectomized rats and genetically altered mice) have underpinned much of what we know about skeletal biology. They have been pivotal for developing therapies for osteoporosis and monogenic skeletal conditions, including osteogenesis imperfecta, achondroplasia, hypophosphatasia, and craniodysplasias. Further therapeutic advances, particularly to improve cortical strength, require improved understanding and more rigorous use and reporting. We describe here how trabecular and cortical bone structure develop, are maintained, and degenerate with aging in mice, rats, and humans, and how cortical bone structure is changed in some preclinical models of endocrine conditions (eg, postmenopausal osteoporosis, chronic kidney disease, hyperparathyroidism, diabetes). We provide examples of preclinical models used to identify and test current therapies for osteoporosis, and discuss common concerns raised when comparing rodent preclinical models to the human skeleton. We focus especially on cortical bone, because it differs between small and larger mammals in its organizational structure. We discuss mechanisms common to mouse and human controlling cortical bone strength and structure, including recent examples revealing genetic contributors to cortical porosity and osteocyte network configurations during growth, maturity, and aging. We conclude with guidelines for clear reporting on mouse models with a goal for better consistency in the use and interpretation of these models.
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Hueso Cortical , Modelos Animales de Enfermedad , Animales , Humanos , Ratas , Ratones , Enfermedades Óseas , RoedoresRESUMEN
Introduction: In 2022, the Minister for Health of Singapore launched Healthier SG, a national strategy in championing the shift towards a population health approach. Method: The Singapore Heart Foundation conducted a series of roundtable discussions, also attended by representatives of the Singapore Cardiac Society and the Chapter of Cardiologists of the Academy of Medicine Singapore. During the meetings, the authors formulated interventions supportive of Healthier SG that specifically aimed to uplift the state of cardiovascular (CV) preventive care in Singapore. Results: In line with Healthier SG, the authors propose a 3-pronged approach ("Healthier Heart SG") to augment the success of Healthier SG in achieving good CV outcomes. This proposal includes the following components: (1) a call to update the standards of care in addressing the 5 main modifiable risk factors of cardiovascular disease (CVD); (2) patient education through cooperation between healthcare professionals and community partners for a whole-of-system approach; and (3) support for integrated care, including access to cardiac rehabilitation in the community, improved referral processes and access to nutrition/dietetics counselling and tobacco cessation, optimal use of information technology, and continued CV research. Conclusion: Healthier Heart SG would bring the standards of care and CV care delivery in Singapore closer to achieving the vision of proactive prevention of CVD and CV morbidity and mortality. This can only be achieved through the concerted efforts of healthcare professionals, policymakers and community partners, coupled with the cooperation of community members.
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Enfermedades Cardiovasculares , Sociedades Médicas , Singapur/epidemiología , Humanos , Enfermedades Cardiovasculares/prevención & control , Cardiología/organización & administración , Educación del Paciente como Asunto , Rehabilitación Cardiaca/métodos , Fundaciones/organización & administración , Factores de Riesgo de Enfermedad CardiacaRESUMEN
Chest pain is the second most common complaint in the emergency department. The need to diagnose the cause of chest pain in a timely manner and appropriately direct care is crucial. This article discusses the role of imaging in acute chest pain, after first differentiating chest pain into cardiac and non-cardiac causes with upfront clinical and biochemical assessment. The role of non-invasive imaging including point-of-care ultrasound, echocardiography, myocardial perfusion imaging, cardiac MRI, coronary computed tomography angiography and novel cardiac CT applications are discussed. Updates in the literature regarding the role of coronary plaque imaging in acute chest pain are reviewed, as are ongoing challenges and future directions. This includes a discussion on the yield of diagnostic testing in low-risk acute chest pain cohorts vs intermediate-high risk cohorts. The incremental value of further testing in the former is low, which is reflected in contemporary guidelines that discourage the use of costly diagnostic tests in these cohorts. In the latter cohort, emerging evidence has shown specifically the role coronary computed tomography angiography could play in reducing the need for invasive coronary angiography in selective patients where the true probability of acute coronary syndrome is thought to be low. Real-world considerations such as accessibility and affordability are also discussed in the paper because while guidelines offer clinicians the flexibility of evidence-based choice, physician decision must necessarily be made in consideration of real-world constraints.
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Dolor en el Pecho , Placa Aterosclerótica , Humanos , Dolor en el Pecho/diagnóstico por imagen , Dolor en el Pecho/etiología , Angiografía Coronaria/métodos , Tomografía Computarizada por Rayos X/métodos , Angiografía por Tomografía Computarizada/efectos adversos , Servicio de Urgencia en HospitalRESUMEN
Obesity is a disease with a major negative impact on human health. However, people with obesity may not perceive their weight to be a significant problem and less than half of patients with obesity are advised by their physicians to lose weight. The purpose of this review is to highlight the importance of managing overweight and obesity by discussing the adverse consequences and impact of obesity. In summary, obesity is strongly related to >50 medical conditions, with many of them having evidence from Mendelian randomisation studies to support causality. The clinical, social and economic burdens of obesity are considerable, with these burdens potentially impacting future generations as well. This review highlights the adverse health and economic consequences of obesity and the importance of an urgent and concerted effort towards the prevention and management of obesity to reduce the burden of obesity.
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Obesidad , Médicos , Humanos , SobrepesoRESUMEN
Obstructive sleep apnoea (OSA) is strongly associated with cardiovascular disease (CVD). However, evidence supporting this association in the Asian population is scarce. Given the differences in the epidemiology of CVD and cardiovascular risk factors, as well as differences in the availability of healthcare resources between Asian and Western countries, an Asian Pacific Society of Cardiology (APSC) working group developed consensus recommendations on the management of OSA in patients with CVD in the Asia-Pacific region. The APSC expert panel reviewed and appraised the available evidence using the Grading of Recommendations Assessment, Development, and Evaluation system. Consensus recommendations were developed and put to an online vote. Consensus was reached when 80% of votes for a given recommendation were in support of 'agree' or 'neutral.' The resulting statements provide guidance on the assessment and treatment of OSA in patients with CVD in the Asia-Pacific region. The APSC hopes for these recommendations to pave the way for screening, early diagnosis and treatment of OSA in the Asia-Pacific region.
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BACKGROUND: Concepts of moral distress (MD) among physicians have evolved and extend beyond the notion of psychological distress caused by being in a situation in which one is constrained from acting on what one knows to be right. With many accounts involving complex personal, professional, legal, ethical and moral issues, we propose a review of current understanding of MD among physicians. METHODS: A systematic evidence-based approach guided systematic scoping review is proposed to map the current concepts of MD among physicians published in PubMed, Embase, PsycINFO, Web of Science, SCOPUS, ERIC and Google Scholar databases. Concurrent and independent thematic and direct content analysis (split approach) was conducted on included articles to enhance the reliability and transparency of the process. The themes and categories identified were combined using the jigsaw perspective to create domains that form the framework of the discussion that follows. RESULTS: A total of 30 156 abstracts were identified, 2473 full-text articles were reviewed and 128 articles were included. The five domains identified were as follows: (1) current concepts, (2) risk factors, (3) impact, (4) tools and (5) interventions. CONCLUSIONS: Initial reviews suggest that MD involves conflicts within a physician's personal beliefs, values and principles (personal constructs) caused by personal, ethical, moral, contextual, professional and sociocultural factors. How these experiences are processed and reflected on and then integrated into the physician's personal constructs impacts their self-concepts of personhood and identity and can result in MD. The ring theory of personhood facilitates an appreciation of how new experiences create dissonance and resonance within personal constructs. These insights allow the forwarding of a new broader concept of MD and a personalised approach to assessing and treating MD. While further studies are required to test these findings, they offer a personalised means of supporting a physician's MD and preventing burn-out.
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Médicos , Humanos , Reproducibilidad de los Resultados , Médicos/psicología , Principios MoralesRESUMEN
Ortner's syndrome, also known as cardiovocal syndrome, encompasses any cardiac or vascular process that affects the recurrent laryngeal nerve(s), subsequently leading to vocal cord palsy. Various causes of Ortner's syndrome have been described in the literature, which include but are not limited to aortic aneurysms, pulmonary hypertension, left atrial enlargement, and congenital cardiac disorders. We hereby present a pictorial review of the more commonly reported entities, which have been implicated in this syndrome. Ultimately, understanding the pathophysiology underlying Ortner's syndrome will help in diagnosis and institution of potentially life-saving treatment.
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Sistema Cardiovascular , Parálisis de los Pliegues Vocales , Ronquera/diagnóstico por imagen , Ronquera/etiología , Humanos , Síndrome , Parálisis de los Pliegues Vocales/diagnóstico por imagenRESUMEN
BACKGROUND: Coronary artery calcium score (CAC) is an objective marker of atherosclerosis. The primary aim is to assess CAC as a risk classifier in stable coronary artery disease (CAD). HYPOTHESIS: CAC improves CAD risk prediction, compared to conventional risk scoring, even in the absence of cardiovascular risk factor inputs. METHODS: Outpatients presenting to a cardiology clinic (n = 3518) were divided into two cohorts: derivation (n = 2344 patients) and validation (n = 1174 patients). Adding logarithmic transformation of CAC, we built two logistic regression models: Model 1 with chest pain history and risk factors and Model 2 including chest pain history only without risk factors simulating patients with undiagnosed comorbidities. The CAD I Consortium Score (CCS) was the conventional reference risk score used. The primary outcome was the presence of coronary artery disease defined as any epicardial artery stenosis≥50% on CT coronary angiogram. RESULTS: Area under curve (AUC) of CCS in our validation cohort was 0.80. The AUC of Models 1 and 2 were significantly improved at 0.88 (95%CI 0.86-0.91) and 0.87 (95%CI 0.84-0.90), respectively. Integrated discriminant improvement was >15% for both models. At a pre-specified cut-off of ≤10% for excluding coronary artery disease, the sensitivity and specificity were 89.3% and 74.7% for Model 1, and 88.1% and 71.8% for Model 2. CONCLUSION: CAC helps improve risk classification in patients with chest pain, even in the absence of prior risk factor screening.
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Calcio , Enfermedad de la Arteria Coronaria , Dolor en el Pecho/diagnóstico , Dolor en el Pecho/epidemiología , Dolor en el Pecho/etiología , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/epidemiología , Humanos , Pacientes Ambulatorios , Clínicas de Dolor , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de RiesgoRESUMEN
INTRODUCTION: Prehabilitation may benefit older patients undergoing major surgeries. Currently, its efficacy has not been conclusively proven. This is a retrospective review of a multimodal prehabilitation programme. METHODS: Patients aged 65 years and above undergoing major abdominal surgery between May 2015 and December 2019 in the National University Hospital were included in our institutional programme that incorporated aspects of multimodal prehabilitation and Enhanced Recovery After Surgery concepts as 1 holistic perioperative pathway to deal with issues specific to older patients. Physical therapy, nutritional advice and psychosocial support were provided as part of prehabilitation. RESULTS: There were 335 patients in the prehabilitation cohort and 256 patients whose records were reviewed as control. No difference in postoperative length of stay (P=0.150) or major complications (P=0.690) were noted. Patients in the prehabilitation group were observed to ambulate a longer distance and participate more actively with their physiotherapists from postoperative day 1 until 4. In the subgroup of patients with cancer, more patients had undergone neoadjuvant therapy in the prehabilitation group compared to the control group (21.7% versus 12.6%, P=0.009). Prehabilitation patients were more likely to proceed to adjuvant chemotherapy (prehabilitation 87.2% vs control 65.6%, P<0.001) if it had been recommended. CONCLUSION: The current study found no differences in traditional surgical outcome measures with and without prehabilitation. An increase in patient mobility in the immediate postoperative period was noted with prehabilitation, as well as an association between prehabilitation and increased adherence to postoperative adjuvant therapy. Larger prospective studies will be needed to validate the findings of this retrospective review.
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Cuidados Preoperatorios , Ejercicio Preoperatorio , Humanos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
The Asian Pacific Society of Cardiology convened a consensus statement panel for optimising cardiovascular (CV) outcomes in type 2 diabetes, and reviewed the current literature. Relevant articles were appraised using the Grading of Recommendations, Assessment, Development and Evaluation system, and consensus statements were developed in two meetings and were confirmed through online voting. The consensus statements indicated that lifestyle interventions must be emphasised for patients with prediabetes, and optimal glucose control should be encouraged when possible. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are recommended for patients with chronic kidney disease with adequate renal function, and for patients with heart failure with reduced ejection fraction. In addition to SGLT2i, glucagon-like peptide-1 receptor agonists are recommended for patients at high risk of CV events. A blood pressure target below 140/90 mmHg is generally recommended for patients with type 2 diabetes. Antiplatelet therapy is recommended for secondary prevention in patients with atherosclerotic CV disease.
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The prevalence of dyslipidaemia has been increasing in the Asia-Pacific region and this is attributed to dietary changes and decreasing physical activity. While there has been substantial progress in dyslipidaemia therapy, its management in the region is hindered by limitations in awareness, adherence and healthcare costs. The Asian Pacific Society of Cardiology (APSC) developed these consensus recommendations to address the need for a unified approach to managing dyslipidaemia. These recommendations are intended to guide general cardiologists and internists in the assessment and treatment of dyslipidaemia and are hoped to pave the way for improving screening, early diagnosis and treatment. The APSC expert panel reviewed and appraised the evidence using the Grading of Recommendations Assessment, Development, and Evaluation system. Consensus recommendations were developed, which were then put to an online vote. The resulting consensus recommendations tackle contemporary issues in the management of dyslipidaemia, familial hypercholesterolaemia and lipoprotein(a) in the Asia-Pacific region.
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INTRODUCTION: Imaging neurovascular disturbances in Parkinson's disease (PD) is an excellent measure of disease severity. Indeed, a disease-specific regional pattern of abnormal metabolism has been identified using positron emission tomography. Only a handful of studies, however, have applied perfusion MRI to detect this disease pattern. Our goal was to replicate the evaluation of a PD-related perfusion pattern using scaled subprofile modeling/principal component analysis (SSM-PCA). METHODS: We applied arterial spin labeling (ASL) MRI for this purpose. Uniquely, we assessed this pattern separately in PD individuals ON and OFF dopamine medications. We further compared the existence of these patterns and their strength in each individual with their Movement Disorder Society-Unified Parkinson's Disease Rating Scale motor (MDS-UPDRS) scores, cholinergic tone as indexed by short-term afferent inhibition (SAI), and other neuropsychiatric tests. RESULTS: We observed a PD-related perfusion pattern that was similar to previous studies. The patterns were observed in both ON and OFF states but only the pattern in the OFF condition could significantly (AUC=0.72) differentiate between PD and healthy subjects. In the ON condition, PD subjects were similar to controls from a CBF standpoint (AUC=0.45). The OFF pattern prominently included the posterior cingulate, precentral region, precuneus, and the subcallosal cortex. Individual principal components from the ON and OFF states were strongly associated with MDS-UPDRS scores, SAI amplitude and latency. CONCLUSION: Using ASL, our study identified patterns of abnormal perfusion in PD and were associated with disease symptoms.
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Circulación Cerebrovascular/fisiología , Angiografía por Resonancia Magnética , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/fisiopatología , Anciano , Femenino , Humanos , Angiografía por Resonancia Magnética/métodos , Masculino , Pruebas de Estado Mental y Demencia , Persona de Mediana Edad , Análisis de Componente Principal , Marcadores de SpinRESUMEN
Introduction: Chest pain is a common symptom for cardiology referrals. The ACC-AHA guidelines recommend exercise stress electrocardiography (TMX) as the initial diagnostic test. However, the TMX only has moderate sensitivity and non-diagnostic cases may require further stress imaging studies. In this study we aimed to look at the feasibility of combining coronary artery calcium (CAC) score with TMX to refine risk stratification. This may be an alternative to stress imaging in cases of non low-risk TMX, with the added advantage of short time turnaround time and low radiation dose. Methods: A total of 145 patients who presented consecutively to the National Heart Centre Singapore with chest pain were included in this study. These were intermediate risk patients with an average Duke Clinical Score of 38.8%. All patients underwent both TMX and computed tomography scan of the coronary arteries (CTCA) which also includes CAC. The primary outcome was defined as obstructive coronary artery disease i.e. >50% left main artery stenosis and/or >70% stenosis in other epicardial arteries. Results: The combination of TMX and CAC was comparable to stress imaging in detecting obstructive coronary artery disease. When added to TMX, CAC has an integrated discriminative improvement of 74.1%, achieved an area under the curve of 0.974 and adjusted R2 of 0.670 in detecting the primary outcome. Conclusion: The strategy of combining TMX and CAC is feasible in clinical practice to refine risk stratification in outpatients with intermediate risk chest pain. The calcium score readout also further guides therapy for primary prevention. Highlights: Treadmill exercise is one of the first line tests for cardiac chest pain work up.Non diagnostic test treadmill results requires further adjunctive tests.Downstream stress imaging causes delay in time to diagnosis.Coronary artery calcium scoring needs minimal preparation with fast turnaround time.Addition of coronary artery calcium to treadmill performs comparably to stress imaging.This is a feasible alternative to risk stratify non diagnostic treadmill tests and guide therapy for primary prevention.
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Calcio/metabolismo , Dolor en el Pecho/diagnóstico , Enfermedad de la Arteria Coronaria/diagnóstico , Vasos Coronarios/diagnóstico por imagen , Prueba de Esfuerzo/métodos , Medición de Riesgo , Biomarcadores/metabolismo , Dolor en el Pecho/epidemiología , Dolor en el Pecho/etiología , Angiografía por Tomografía Computarizada , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/metabolismo , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Singapur/epidemiologíaRESUMEN
The human brain is remarkably plastic. The brain changes dramatically across development, with ongoing functional development continuing well into the third decade of life and substantial changes occurring again in older age. Dynamic changes in brain function are thought to underlie the innumerable changes in cognition, emotion, and behavior that occur across development. The brain also changes in response to experience, which raises important questions about how the environment influences the developing brain. Longitudinal functional magnetic resonance imaging (fMRI) studies are an essential means of understanding these developmental changes and their cognitive, emotional, and behavioral correlates. This paper provides an overview of common statistical models of longitudinal change applicable to developmental cognitive neuroscience, and a review of the functionality provided by major software packages for longitudinal fMRI analysis. We demonstrate that there are important developmental questions that cannot be answered using available software. We propose alternative approaches for addressing problems that are commonly faced in modeling developmental change with fMRI data.
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Mapeo Encefálico/métodos , Encéfalo/fisiología , Imagen por Resonancia Magnética/métodos , Humanos , Estudios LongitudinalesRESUMEN
Cerebrovascular disease, especially small vessel pathology, is the leading comorbidity in degenerative disorders. We applied arterial spin labeling and cerebrovascular reserve (CVR) imaging to quantify small vessel disease and study its effect on cognitive symptoms in nondemented older adults from a community-based cohort. We evaluated baseline cerebral blood flow (CBF) using arterial spin labeling and percent signal change as a marker of CVR using blood-oxygen level-dependent imaging following a breath-hold stimulus. Measurements were performed in and near white matter hyperintensities, which are currently the standard to assess severity of vascular pathology. We show that similar to other studies (1) CBF and CVR are markedly reduced in the hyperintensities as well as in the tissue surrounding them, indicating susceptibility to infarction; (2) low CBF and CVR are significantly correlated with poor cognitive performance; and (3) in addition, compared to a 58.4% reduction in CBF, larger exhaustion (79.3%) of CVR was observed in the hyperintensities with a faster, nonlinear rate of decline. We conclude that CVR may be a more sensitive biomarker of small vessel disease than CBF.