Publications by authors named "Samuel Wann"

Article Synopsis
  • Industrialized environments, while offering benefits such as better education and lower infection rates, may contribute to brain atrophy, prompting a comparison of brain volume changes in industrialized versus non-industrialized populations.* -
  • The Tsimane and Moseten are two indigenous Bolivian groups studied, with the Tsimane showing increased brain volume in certain areas with age, while the UK Biobank participants experience a significant decrease in brain volume over time, particularly in frontal and temporal regions.* -
  • The findings suggest that lifestyle factors, including physical activity levels, may influence brain volume changes, with Tsimane males exhibiting surprising increases in some brain areas, while Tsimane females show greater decreases compared to UK Biobank females.*
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The ancient Egyptians considered the heart to be the most important organ. The belief that the heart remained in the body is widespread in the archeological and paleopathological literature. The purpose of this study was to perform an overview of the preserved intrathoracic structures and thoracic and abdominal cavity filling, and to determine the prevalence and computed tomography (CT) characteristics of the myocardium in the preserved hearts of ancient Egyptian mummies.

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Background: In industrialized populations, low male testosterone is associated with higher rates of cardiovascular mortality. However, coronary risk factors like obesity impact both testosterone and cardiovascular outcomes. Here, we assess the role of endogenous testosterone on coronary artery calcium in an active subsistence population with relatively low testosterone levels, low cardiovascular risk and low coronary artery calcium scores.

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Article Synopsis
  • This study investigates brain aging and dementia in two indigenous South American populations, the Tsimane and Moseten, to understand brain volume (BV) changes in a nonindustrialized context.
  • It analyzes data from 1,165 individuals aged 40 to 94, revealing that BV declines with age but at a slower rate compared to industrialized populations.
  • The findings support the "embarrassment of riches" model, suggesting that a balanced energy intake during active lifestyles promotes better brain health, while excess body weight negatively impacts BV in modern societies.
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In response to the growing evidence that hypertension may play a significant role in the development of cardiovascular disease (CVD) in bonobos, the Great Ape Heart Project established a finger blood pressure (BP) monitoring protocol for zoo-housed bonobos. The ability to monitor BP without the use of anesthesia provides more opportunities to detect potential hypertension in its early stages allowing for therapeutic intervention that may slow the progression of CVD. No BP reference ranges exist for bonobos due to the lack of an established protocol, the difficulty of measuring BP in animals, and small sample size of zoo-housed bonobos.

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Cardiology has progressed beyond classic auscultation, but the doctor-patient relationship must be preserved.

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Introduction: We evaluated the prevalence of dementia and mild cognitive impairment (MCI) in indigenous Tsimane and Moseten, who lead a subsistence lifestyle.

Methods: Participants from population-based samples ≥ 60 years of age (n = 623) were assessed using adapted versions of the Modified Mini-Mental State Examination, informant interview, longitudinal cognitive testing and brain computed tomography (CT) scans.

Results: Tsimane exhibited five cases of dementia (among n = 435; crude prevalence = 1.

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Acute aortic syndrome (AAS) includes the entities of acute aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer. AAS typically presents with sudden onset of severe, tearing, anterior, or interscapular back pain. Symptoms may be dominated by malperfusion syndrome, due to obstruction of the lumen of the aorta and/or a side branch when the intimal and medial layers are separated.

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The sternal foramen, usually an asymptomatic osteological defect, can lead to catastrophic consequences if not recognized prior to certain medical procedures. This study reports the prevalence of a sternal foramen in two South Amerindian populations compared with other published populations. We evaluated the presence of sternal foramina using thoracic computed tomography scans of 1334 (48% female) participants from two indigenous populations of Bolivia (n = 900 Tsimane, 434 Moseten).

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Brain atrophy is correlated with risk of cognitive impairment, functional decline, and dementia. Despite a high infectious disease burden, Tsimane forager-horticulturists of Bolivia have the lowest prevalence of coronary atherosclerosis of any studied population and present few cardiovascular disease (CVD) risk factors despite a high burden of infections and therefore inflammation. This study (a) examines the statistical association between brain volume (BV) and age for Tsimane and (b) compares this association to that of 3 industrialized populations in the United States and Europe.

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Infective endocarditis can involve a normal, abnormal, or prosthetic cardiac valve. The diagnosis is typically made clinically with persistently positive blood cultures, characteristic signs and symptoms, and echocardiographic evidence of valvular vegetations or valvular complications such as abscess, dehiscence, or new regurgitation. Imaging plays an important role in the initial diagnosis of infective endocarditis, identifying complications, prognostication, and informing the next steps in therapy.

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ACR Appropriateness Criteria® Syncope.

J Am Coll Radiol

May 2021

Syncope and presyncope lead to well over one million emergency room visits in the United States each year. Elucidating the cause of syncope or presyncope, which are grouped together given similar etiologies and outcomes, can be exceedingly difficult given the diverse etiologies. This becomes more challenging as some causes, such as vasovagal syncope, are relatively innocuous while others, such as cardiac-related syncope, carry a significant increased risk of death.

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Coronary atherosclerotic disease is a leading cause of mortality and morbidity due to major cardiovascular events in the United States and abroad. Risk stratification and early preventive measures can reduce major cardiovascular events given the long latent asymptomatic period. Imaging tests can detect subclinical coronary atherosclerosis and aid initiation of targeted preventative efforts based on patient risk.

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Nonischemic cardiomyopathies encompass a broad spectrum of myocardial disorders with mechanical or electrical dysfunction without evidence of ischemia. There are five broad variants of nonischemic cardiomyopathies; hypertrophic cardiomyopathy (Variant 1), restrictive or infiltrative cardiomyopathy (Variant 2), dilated or unclassified cardiomyopathy (Variant 3), arrhythmogenic cardiomyopathy (Variant 4), and inflammatory cardiomyopathy (Variant 5). For variants 1, 3, and 4, resting transthoracic echocardiography, MRI heart function and morphology without and with contrast, and MRI heart function and morphology without contrast are the usually appropriate imaging modalities.

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Background: Atrial fibrillation is the most common arrhythmia in post-industrialized populations. Older age, hypertension, obesity, chronic inflammation, and diabetes are significant atrial fibrillation risk factors, suggesting that modern urban environments may promote atrial fibrillation.

Objective: Here we assess atrial fibrillation prevalence and incidence among tropical horticulturalists of the Bolivian Amazon with high levels of physical activity, a lean diet, and minimal coronary atherosclerosis, but also high infectious disease burden and associated inflammation.

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Blunt cardiac injuries range from myocardial concussion (commotio cordis) leading to fatal ventricular arrhythmias to myocardial contusion, cardiac chamber rupture, septal rupture, pericardial rupture, and valvular injuries. Blunt injuries account for one-fourth of the traumatic deaths in the United States. Chest radiography, transthoracic echocardiography, CT chest with and without contrast, and CT angiography are usually appropriate as the initial examination in patients with suspected blunt cardiac injury who are both hemodynamically stable and unstable.

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Patients with acute nonspecific chest pain and low probability for coronary disease remain an important clinical management dilemma. We focus on evidence for imaging, in an integrated decision-making setting. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel.

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