Publications by authors named "Larry W Markham"

Introduction/aims: Skeletal muscle magnetic resonance imaging (MRI) is a validated noninvasive tool to assess Duchenne muscular dystrophy (DMD) progression. There is interest in finding DMD biomarkers that decrease the burden of clinical trial participation, such as wearable devices. Our aim was to evaluate the relationship between activity, via accelerometry, and skeletal muscle MRI, particularly T mapping.

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Article Synopsis
  • Cardiomyopathy is a major cause of death in boys with Duchenne muscular dystrophy (DMD), and this study investigates cardiac function using cardiac magnetic resonance (CMR) imaging to compare DMD patients with healthy controls.
  • The study involved 179 DMD patients and 96 healthy controls, focusing on measuring left ventricular (LV) function, with findings demonstrating significant differences in ventricular volumes and ejection rates, indicating compromised cardiac function in DMD patients.
  • Results suggest that certain CMR filling and ejection indices correlate with increased mortality in DMD patients, highlighting the potential for these measures to serve as important prognostic tools.
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Cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD); however, in the mdx mouse model of DMD, the cardiac phenotype differs from that seen in DMD-associated cardiomyopathy. Although some have used pharmacologic stress to stimulate injury and enhance cardiac pathology in the mdx model, many methods lead to high mortality with variable cardiac outcomes, and do not recapitulate the structural and functional cardiac changes seen in human disease. Here, we describe a simple and effective method to enhance the cardiac phenotype model in mdx mice using advanced 2D and 4D high-frequency ultrasound to monitor cardiac dysfunction progression in vivo.

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Aortic valve disease results in left ventricular (LV) dilation and/or hypertrophy. Valve intervention may improve, but not normalize flow dynamics. We hypothesized that LV remodeling would be more favorable following the Ross procedure versus mechanical aortic valve replacement (mAVR).

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Background: Cardiovascular disease is the leading cause of death among patients with Duchenne muscular dystrophy (DMD). Identifying patients at risk of early death could allow for increased monitoring and more intensive therapy. Measures that associate with death could serve as surrogate outcomes in clinical trials.

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Cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD), however, in the mouse model of DMD, the cardiac phenotype differs from that seen in DMD-associated cardiomyopathy. Although some have used pharmacologic stress to enhance the cardiac phenotype in the model, many methods lead to high mortality, variable cardiac outcomes, and do not recapitulate the structural and functional cardiac changes seen in human disease. Here, we describe a simple and effective method to enhance the cardiac phenotype model in mice using advanced 2D and 4D high-frequency ultrasound to monitor cardiac dysfunction progression .

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Background: Fontan-associated liver disease (FALD) refers to structural and functional changes of the liver caused by the physiology of the Fontan palliation. Currently, liver biopsy is the gold standard to assess liver fibrosis of FALD.

Aim: Investigate biomarkers correlating with severity of liver biopsy fibrosis in FALD.

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Background: Cardiomyopathy (CMP) is the leading cause of death in Duchenne muscular dystrophy (DMD). Characterization of disease trajectory can be challenging, especially in the early stage of CMP where onset and clinical progression may vary. Traditional metrics from cardiovascular magnetic resonance (CMR) imaging such as LVEF (left ventricular ejection fraction) and LGE (late gadolinium enhancement) are often insufficient for assessing disease trajectory.

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Background: Cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD). Cardiac magnetic resonance (CMR) parametric mapping sequences offer insights into disease pathophysiology. We propose a novel approach by leveraging T2 mapping in conjunction with T1 and extracellular volume (ECV) mapping to perform a virtual myocardial biopsy.

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Article Synopsis
  • Cardiopulmonary failure is the leading cause of death in Duchenne muscular dystrophy (DMD), and this study aims to identify cardiac measures that correlate with all-cause mortality to improve future therapeutic trials.
  • Seventy-eight DMD patients underwent extensive cardiac assessments, including cardiac magnetic resonance imaging and blood biomarker analysis, with a focus on metrics like left ventricular ejection fraction and specific protein levels.
  • The findings indicate that left ventricular ejection fraction, indexed volumes, certain strain measures, and the biomarker NT-proBNP are significantly associated with all-cause mortality, suggesting they are viable endpoints for future DMD treatments.
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Background: Neurocognitive dysfunction (NCD) is a common comorbidity among children with congenital heart disease (CHD). However, it is unclear how underlying CHD and its sequelae combine with genetics and acquired cardiovascular and neurological disease to impact NCD and outcomes across the lifespan in adults with CHD.

Methods: The Multi-Institutional Neurocognitive Discovery Study in Adults with Congenital Heart Disease (MINDS-ACHD) is a partnership between the Pediatric Heart Network (PHN) and the Adult Alliance for Research in Congenital Cardiology (AARCC) that examines objective and subjective neurocognitive function and genetics in young ACHD.

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Background: Cardiomyopathy (CMP) is the most common cause of mortality in Duchenne muscular dystrophy (DMD), though the age of onset and clinical progression vary. We applied a novel 4D (3D + time) strain analysis method using cine cardiovascular magnetic resonance (CMR) imaging data to determine if localized strain metrics derived from 4D image analysis would be sensitive and specific for characterizing DMD CMP.

Methods: We analyzed short-axis cine CMR image stacks from 43 DMD patients (median age: 12.

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Background: Duchenne muscular dystrophy (DMD) is associated with progressive muscle weakness and respiratory decline. To date, studies have focused on respiratory decline and loss of ambulation as a metric of loss of skeletal muscle strength. However, new functional measures can assess skeletal muscle disease regardless of ambulatory status.

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Continuous advances in pediatric cardiology, surgery, and critical care have significantly improved survival rates for children and adults with congenital heart disease. Paradoxically, the resulting increase in longevity has expanded the prevalence of both repaired and unrepaired congenital heart disease and has escalated the need for diagnostic and interventional procedures. Because of this expansion in prevalence, anesthesiologists, pediatricians, and other health care professionals increasingly encounter patients with congenital heart disease or other pediatric cardiac diseases who are presenting for surgical treatment of unrelated, noncardiac disease.

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Cardiomyopathy (CM) is the leading cause of death for individuals with Duchenne muscular dystrophy (DMD). While DMD CM progresses rapidly and fatally for some in teenage years, others can live relatively symptom-free into their thirties or forties. Because CM progression is variable, there is a critical need for biomarkers to detect early onset and rapid progression.

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Cardiovascular disease is the leading cause of death in patients with Duchenne Muscular Dystrophy (DMD), but there is significant cardiomyopathy phenotypic variability. Some patients demonstrate rapidly progressive disease and die at a young age while others survive into the fourth decade. Criteria to identify DMD subjects at greatest risk for early mortality could allow for increased monitoring and more intensive therapy.

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Duchenne muscular dystrophy (DMD) is characterized by muscle deterioration and progressive weakness. As a result, patients with DMD have significant cardiopulmonary morbidity and mortality that worsens with age and loss of ambulation. Since most validated muscle assessments require ambulation, new functional measures of DMD progression are needed.

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Current approaches to stratify the risk for disease progression in thoracic aortic aneurysm (TAA) lack precision, which hinders clinical decision making. Connective tissue phenotyping of children with TAA previously identified the association between skin striae and increased rate of aortic dilation. The objective of this study was to analyze associations between connective tissue abnormalities and clinical endpoints in adults with aortopathy.

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Background: Cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD), but studies suggest heart failure biomarkers correlate poorly with cardiomyopathy severity. DMD clinical trials have used troponin I (cTnI) as a biomarker of toxicity, but it is unclear if asymptomatic DMD patients have elevated cTnI. We longitudinally evaluated cTnI, brain natriuretic peptide (BNP), and N-terminal pro-BNP (NT-proBNP) in a DMD cohort.

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Background: Duchenne muscular dystrophy (DMD) leads to progressive cardiomyopathy. Detection of myocardial fibrosis with late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) is critical for clinical management. Due to concerns of brain deposition of gadolinium, non-contrast methods for detecting and monitoring myocardial fibrosis would be beneficial.

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Cardiac disease is now the leading cause of death in Duchenne muscular dystrophy (DMD). Clinical evaluations over time have demonstrated asymptomatic cardiac troponin elevations and acute elevations are associated with symptoms and cardiac dysfunction in DMD. Clinicians require a better understanding of the relationship of symptoms, troponin levels and progression of cardiac disease in DMD.

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While survival for children with hypoplastic left heart syndrome (HLHS) has improved, compromised cardiac output and oxygen delivery persist, and children show cognitive deficits. Most research has assessed young children on broad cognitive indices; less is known about specific indices in older youth. In this pilot study, cognitive function and attention in youth ages 8 to 16 years with HLHS (n = 20) was assessed with the Wechsler Intelligence Scale for Children - Fifth Edition (WISC-V) and NIH Toolbox Cognition Battery (NTCB); parents completed the Child Behavior Checklist.

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Brain-derived neurotrophic factor (BDNF) is a neuronal growth and survival factor that harbors cardioprotective qualities that may attenuate dilated cardiomyopathy. In ~30% of the population, BDNF has a common, nonsynonymous single nucleotide polymorphism rs6265 (Val66Met), which might be correlated with increased risk of cardiovascular events. We previously showed that BDNF correlates with better cardiac function in Duchenne muscular dystrophy (DMD) patients.

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Longitudinal changes in aortic diameters of young patients with thoracic aortic aneurysm (TAA) have not been completely described, particularly over long periods of follow-up. This retrospective study sought to characterize the rates of proximal aortic dilation in young patients, identify risk factors for TAA progression, and evaluate the predictive utility of early echocardiographic follow-up. Inclusion criteria were: (1) TAA or TAA-predisposing genetic diagnosis, (2) age < 25 years at first echocardiogram, and (3) minimum of 5 years of echocardiographic follow-up.

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