Reduced-order models of wall shear stress patterns in the left atrial appendage from a data-augmented atrial database.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting over 1% of the population. It is usually triggered by irregular electrical impulses that cause the atria to contract irregularly and ineffectively. It increases blood stasis and the risk of thrombus formation within the left atrial appendage (LAA) and aggravates adverse atrial remodeling. Despite recent efforts, LAA flow patterns representative of AF conditions and their association with LAA stasis remain poorly characterized. AIM: To develop reduced-order data-driven models of LAA flow patterns during atrial remodeling in order to uncover flow disturbances concurrent with LAA stasis that could add granularity to clinical decision criteria. METHODS: We combined a geometric data augmentation process with projection of results from 180 CFD atrial simulations on a universal LAA coordinate (ULAAC) system. The projection approach enhances data visualization and facilitates direct comparison between different anatomical and functional states. ULAAC projections were used as input for a proper orthogonal decomposition (POD) algorithm to build reduced-order models of hemodynamic metrics, extracting flow characteristics associated with AF and non-AF anatomies. RESULTS: We verified that the ULAAC system provides an adequate representation to visualize data distributions on the LAA surface and to build POD-based reduced-order models. These models revealed significant differences in LAA flow patterns for atrial geometries that underwent adverse atrial remodeling and experienced elevated blood stasis. Together with anatomical morphing-based patient-specific data augmentation, this approach could facilitate data-driven analyses to identify flow features associated with thrombosis risk due to atrial remodeling.

A comprehensive comparison of various patient-specific CFD models of the left atrium for atrial fibrillation patients.

BACKGROUND: Recently, advances in medical imaging, segmentation techniques, and high-performance computing have supported the use of patient-specific computational fluid dynamics (CFD) simulations. At present, CFD-compatible atrium geometries can be easily reconstructed from atrium images, providing important insight into the atrial fibrillation (AF) phenomenon, and assistance during therapy selection and surgical procedures. However, the hypothesis assumed for such CFD models should be adequately validated. AIM: This work aims to perform an extensive study of the different hypotheses that are commonly assumed when performing atrial simulations for AF patients, as well as to evaluate and compare the range of indices that are usually applied to assess thrombus formation within the left atrium appendage (LAA). METHODS: The atrial geometries of two AF patients have been segmented. The resulting geometries have been registered and interpolated to construct a dynamic mesh, which has been employed to compare the rigid and flexible models. Two families of hemodynamic indices have been calculated and compared: wall shear-based and blood age distribution-based. RESULTS: The findings of this study illustrate the importance of validating the rigid atrium hypothesis when utilizing an AF CFD model. In particular, the absence of the A-wave contraction does not avoid a certain degree of passive atrial contraction, making the rigid model a poor approximation in some cases. Moreover, a new thrombosis predicting index has been proposed, i.e., M4, which has been shown to predict stasis more effectively than other indicators.

Pharmacologic interventions for prevention of delirium in hospitalized older people: A meta-analysis.

INTRODUCTION: To comprehensively assess the effects of pharmacologic interventions for prevention of delirium in hospitalized older people. MATERIALS AND METHODS: A systematic review with meta-analysis following Preferred Reporting Items for Systematic reviews and Meta-Analyses methodology was performed. Hospitalized people aged 65 and older, recruited to randomized controlled clinical trials. The electronic databases MEDLINE, EMBASE, WOS and Cochrane Central Register of Controlled Trials were consulted (March 2019). Predefined criteria were used to determine inclusion of studies and to assess their methodologic quality. RESULTS: 1855 records were identified in the database, and after removing the duplicates, the titles and abstracts evaluated were 1250 records. Finally, 25 randomized controlled trials contributed to meta-analysis (n = 5820): 1 anti-epileptics (n = 697), 2 anti-inflammatories (n = 615), 4 antipsychotics (n = 1193), 2 cholinesterase inhibitors (n = 87), 13 hypnotics/sedatives (n = 2909), 1 opioids (n = 52), 1 psychostimulants/nootropics (n = 81), 1 yokukansan (n = 186). Olanzapine (RR = 0.36; 95 %CI: 0.24, 0.52; k = 1; n = 400), rivastigmine (RR = 0.36; 95 %CI: 0.15, 0.87; k = 1; n = 62), dexmedetomidine (RR = 0.52; 95 %CI: 0.38, 0.71; I²â€¯= 55 %; k = 6; n = 2084), and ramelteon (RR = 0.09; 95 %CI: 0.01, 0.64; k = 1; n = 65) reduced the incidence of delirium compared to placebo/usual care. Only dexmedetomidine was also associated with a shorter duration of delirium (0.70 days reduction) and a lower consumption of psychotropic drugs (48 %). No effect was found in mortality, adverse events, urinary tract infections or post-operative complications. CONCLUSIONS: This meta-analysis suggests that dexmedetomidine is effective in reducing the incidence and duration of delirium in hospitalized older patients. Individual studies reveal effects of ramelteon, olanzapine and rivastigmine on the incidence of delirium but the evidence is insufficient to draw a robust conclusion.

Are differences between patient and provider explanatory models of diabetes associated with patient self-management and glycemic control?

In this study we test whether differences between patient and provider explanatory models of diabetes affect self-management and glucose control in type 2 diabetes patients. Diabetic patients (n=60) and family practice physicians (n=39) in Guadalajara, Mexico, responded to a structured explanatory model interview (130 questions on causes, symptoms, and treatments). A cultural consensus analysis indicated a widely shared model among physicians and provided a single shared set of answers to the questions. Patient-provider congruence in beliefs was assessed by comparing each patient's responses with the physician answer set. Congruence in beliefs predicted self-management behaviors (r=0.27, p=.03), more than educational level (r=0.16, p=.23), but was not predictive of A1C (r=0.12, p=.40). Differences between patient and physician explanatory models can adversely affect patient-directed activities and may indirectly affect glycemic control by affecting self-management. These differences may be due to low patient educational level and resulting problems in understanding biomedical approaches to diabetes.

[Sacrococcygeal teratoma: report of a case and review of the literature]. / Teratoma sacrococcígeo: reporte de un caso y revisión de la bibliografía.

Sacrococcygeal teratoma is the most common tumor in infants. About 80% of these tumors are types 1 and 2, and are unlikely to cause metastases whose incidence is 10% in the neonatal period, against nearly 100% at the age of 3 years. These tumors can acquire huge and contain large proportions depriving blood flows to the developing fetus, the tumor hypervascularity generates a hyperdynamic state in the fetus, and that as the tumor grows, it increases its flow to behave as a short circuit and to be similar to that of the lower limbs of the fetus, increasing venous return and cardiac output, heart failure causing fetal and maternal eclampsia.

Cross-cultural perspectives on physician and lay models of the common cold.

We compare physicians and laypeople within and across cultures, focusing on similarities and differences across samples, to determine whether cultural differences or lay-professional differences have a greater effect on explanatory models of the common cold. Data on explanatory models for the common cold were collected from physicians and laypeople in South Texas and Guadalajara, Mexico. Structured interview materials were developed on the basis of open-ended interviews with samples of lay informants at each locale. A structured questionnaire was used to collect information from each sample on causes, symptoms, and treatments for the common cold. Consensus analysis was used to estimate the cultural beliefs for each sample. Instead of systematic differences between samples based on nationality or level of professional training, all four samples largely shared a single-explanatory model of the common cold, with some differences on subthemes, such as the role of hot and cold forces in the etiology of the common cold. An evaluation of our findings indicates that, although there has been conjecture about whether cultural or lay-professional differences are of greater importance in understanding variation in explanatory models of disease and illness, systematic data collected on community and professional beliefs indicate that such differences may be a function of the specific illness. Further generalizations about lay-professional differences need to be based on detailed data for a variety of illnesses, to discern patterns that may be present. Finally, a systematic approach indicates that agreement across individual explanatory models is sufficient to allow for a community-level explanatory model of the common cold.

Evaluation and effects of the Omron 725 CIC device for measuring blood pressure in a hypertension clinic.

BACKGROUND: We compared the Omron 725 CIC device (Omron Healthcare Inc., Vernon Hills, Illinois, USA), which is designed to register the blood pressure on the arm, with a mercury sphygmomanometer. In addition, we evaluated the possible impact that this device might have on the decisions made in a hypertension clinic. METHODS: Patients (n=183) older than 18 years (range 18-84 years) with a wide range of systolic (87-197 mmHg) and diastolic (48-108 mmHg) blood pressures were included. Some of the standards of the Association for the Advancement of Medical Instrumentation and of the British Hypertension Society were used to evaluate the results of the automated device in clinical practice. RESULTS: Using Bland-Altman analysis, an underestimation of both measures was observed with the automated Omron 725 CIC device; the systolic pressure was 3.6+/-8.8 mmHg too low with a very wide range of -13.7 to 20.9 and the diastolic pressure was also 4.4+/-6.3 mmHg too low with a range of -8.1 to 16.9. Clinical decisions could have been changed in 24 of the 116 hypertensive patients (20.6%) if the readings of the automated device had been used instead of using the readings of a mercury sphygmomanometer. These could have included modifying the dosage or changing the medicine used. CONCLUSION: The blood pressure measurements by Omron 725 CIC are different from those of blood pressure readings taken with a mercury sphygmomanometer and this could affect clinical decisions in the diagnosis and follow-up of a hypertensive patient in an office environment.

"Diabetes is my companion": lifestyle and self-management among good and poor control Mexican diabetic patients.

This paper identifies naturally occurring lifestyle and self-care practices in managing type 2 diabetes mellitus that are associated with good glycemic control. In-depth, qualitative interviews were conducted in Guadalajara, Mexico, with 31 matched pairs of good and poor control diabetic patients (n=62), who were matched on their duration of disease and use of medications. While many themes were listed by both groups, a comparison of the responses indicated that themes of daily exercise with a preference for walking, eating beef and milk rather than chicken and fish, economic issues, and emotional issues distinguished poor-control patients. Good-control patients were more likely to have a negative reaction to their initial diagnosis, take a more comprehensive approach to control, eat only two meals a day (plus snacks), use noncaloric beverages to satisfy desires for more food, and know what their blood sugar levels should be.

A cross-cultural approach to the study of the folk illness nervios.

To systematically study and document regional variations in descriptions of nervios, we undertook a multisite comparative study of the illness among Puerto Ricans, Mexicans, Mexican Americans, and Guatemalans. We also conducted a parallel study on susto (Weller et al. 2002, Culture, Medicine and Psychiatry 26(4): 449-472), which allows for a systematic comparison of these illnesses across sites. The focus of this paper is inter- and intracultural variations in descriptions in four Latino populations of the causes, symptoms, and treatments of nervios, as well as similarities and differences between nervios and susto in these same communities. We found agreement among all four samples on a core description of nervios, as well as some overlap in aspects of nervios and susto. However, nervios is a much broader illness, related more to continual stresses. In contrast, susto seems to be related to a single stressful event.

Effect of standard cuff on blood pressure readings in patients with obese arms. How frequent are arms of a 'large circumference'?

OBJECTIVE: To measure the effect on blood pressure readings when a standard cuff is used on patients with arms of a large circumference, and to determine the frequency of arms of a large circumference. SUBJECTS: Blood pressures were taken in 120 subjects with an arm circumference greater than 33 cm. Also, the arm circumference was determined in 244 patients from a family health unit, and in 216 patients from a hypertension clinic. METHOD: A mercury sphygmomanometer and two different cuff sizes were used in a random sequence; therefore, 60 patients' blood pressure were first measured with a large cuff, followed by a standard cuff; the opposite sequence was then applied for another 60 patients. With the obtained values and using a regression analysis, the difference in blood pressure overestimation was calculated. Arm circumference measurement percentages were used to determine the frequency of arms of a large circumference. RESULTS: Both systolic and diastolic blood pressures were significantly greater when the standard cuff was used. For every 5 cm increase in arm circumference, starting at 35 cm, a 2-5 mmHg increase in systolic blood pressure, and a 1-3 mmHg increase in diastolic blood pressure was observed. The prevalence of arms with a large circumference in the family medicine unit and hypertension clinic was 42% and 41.8%, respectively. CONCLUSIONS: There is an overestimation of blood pressure when a standard cuff is used in obese subjects. The high prevalence of these individuals in our environment, both in the hypertensive and normotensive population, makes it necessary to have on hand different sizes of cuffs for taking blood pressure in order to avoid incorrect decisions.

Regional variation in Latino descriptions of susto.

Susto, a folk illness not recognized by biomedical practitioners as a disease, is now formally part of the diagnostic classification system in psychiatry as a "culture-bound syndrome." Susto has been reported among diverse groups of Latin Americans, but most of those reports are several decades old and many were conducted in Indian communities. This study focuses on contemporary descriptions of susto and uses a cross-cultural, comparative design to describe susto in three diverse Latino populations. Mestizo/ladino populations were interviewed in Guatemala, Mexico, and south Texas. An initial set of open-ended interviews was conducted with a sample of "key" informants at each site to obtain descriptive information about susto. A structured interview protocol was developed for use at all three sites, incorporating information from those initial interviews. A second set of structured interviews was then conducted with a representative sample at each site. Results indicate a good deal of consistency in reports of what susto is: what causes it, its symptoms, and how to treat it. There appear to be, however, some notable regional variations in treatments and a difference between past descriptions and contemporary reports of etiology.