Swenne Becker to Mr. Meredith (3 October 1962)

https://egrove.olemiss.edu/mercorr_pro/1186/thumbnail.jp

Subtraction electrocardiography: Detection of ischemia-induced ST displacement without the need to identify the J point

AbstractBackgroundWhen triaging a patient with acute chest pain at first medical contact, an electrocardiogram (ECG) is routinely made and inspected for signs of myocardial ischemia. The guidelines recommend comparison of the acute and an earlier-made ECG, when available. No concrete recommendations for this comparison exist, neither is known how to handle J-point identification difficulties. Here we present a J-point independent method for such a comparison.MethodsAfter conversion to vectorcardiograms, baseline and acute ischemic ECGs after 3minutes of balloon occlusion during elective PCI were compared in 81 patients of the STAFF III ECG database. Baseline vectorcardiograms were subtracted from ischemic vectorcardiograms using either the QRS onsets or the J points as synchronization instants, yielding vector magnitude difference signals, ΔH. Output variables for the J-point synchronized differences were ΔH at the actual J point and at 20, 40, 60 and 80ms thereafter. Output variables for the onset-QRS synchronized differences were the ΔH at 80, 100, 120, 140 and 160ms after onset QRS. Finally, linear regressions of all combinations of ΔHJ+… versus ΔHQRS+… were made, and the best combination was identified.ResultsThe highest correlation, 0.93 (p<0.01), was found between ΔH 40ms after the J point and 160ms after the onset of the QRS complex. With a ΔH ischemia threshold of 0.05mV, 66/81 (J-point synchronized differences) and 68/81 (onset-QRS synchronized differences) subjects were above the ischemia threshold, corresponding to sensitivities of 81% and 84%, respectively.ConclusionOur current study opens an alternative way to detect cardiac ischemia without the need for human expertise for determination of the J point by measuring the difference vector magnitude at 160ms after the onset of the QRS complex

Hur AI-verktyget ChatGPT klarar en hemtentamen i palliativ vård

Dataprogrammet ChatGPT är en bott som utför automatiska uppgifter. Denna chattbott skapade rubriker under hösten på grund av dess förmåga att med artificiell intelligens (AI) skapa svar på riktade frågor och texter utifrån ett beskrivet syfte. I slutet av december 2022 lades 16 frågor från en hemtentamen i palliativ vård vid sjuksköterskeprogrammet in i AI-botten för att få dem besvarade och testa bottens förmåga att besvara frågorna korrekt. Vi ville även testa om man kunde se någon skillnad på svaren i rättningsmallen och på studenternas svar och på de svar som genererats från AI-botten. En bedömning av bottens svar visade på att den hade klarat examinationen. Somliga svar var mycket bra och resonerande till sin natur, något gav reducerade poäng pga. bristande innehåll och ett par svar felaktiga. Ett svar stack ut då det var på engelska. Svaren hade ibland smärre grammatiska fel, men var främst betydligt längre och bättre strukturerade än studerandes. Möjligheten att upptäcka försök till vilseledande i examination hade varit liten. Det finns skillnad i svarens diskurs, där svaren från botten har en mer amerikansk stil i sin formulering.  ENGLSIH ABSTRACT How the AI tool ChatGPT passes a home exam in palliative care The ChatGPT computer program is a bot that performs automatic tasks. This chatbot made headlines during the fall due to its ability to use Artificial Intelligence (AI) to create answers to targeted questions and texts based on a described purpose. At the end of December 2022, 16 questions from a home exam in palliative care at the nursing program were put into the AI bot to get them answered and test its ability to answer the questions correctly but also an assessment of whether the answers could be detected. An evaluation of the bot’s answers showed it had passed the examination. Some answers were excellent and reasoned, some gave reduced points due to lack of content, and some were incorrect. One answer stood out as it was in English. The answers sometimes had minor grammatical errors but were significantly more prolonged and better structured than the students’ answers. The possibility of detecting attempts at deception in the examination had been limited. There is a difference in discourse in the answers, with the answers from the bot having a more American style

Exercise-Induced Repolarization Alternans Heterogeneity in Patients with an Implanted Cardiac Defibrillator

Abstract Repolarization alternans (RA

Enhanced adaptive matched filter for automated identification and measurement of electrocardiographic alternans

Electrocardiographic alternans, consisting of P-wave alternans (PWA), QRS-complex alternans (QRSA) and Twave alternans (TWA), is an index of cardiac risk. However, only automated TWA measurement methods have been proposed so far. Here, we presented the enhanced adaptive matched filter (EAMF) method and tested its reliability in both simulated and experimental conditions. Our methodological novelty consists in the introduction of a signal enhancement procedure according to which all sections of the electrocardiogram (ECG) but the wave of interest are set to baseline, and in the extraction of the alternans area (AAr) in addition to the standard alternans amplitude (AAm). Simulated data consisted of 27 simulated ECGs representing all combinations of PWA, QRSA and TWA of low (10 mu V) and high (100 mu V) amplitude. Experimental data consisted of exercise 12-lead ECGs from 266 heart failure patients with an implanted cardioverter defibrillator for primary prevention. EAMF was able to accurately identify and measure all kinds of simulated alternans (absolute maximum error equal to 2%). Moreover, different alternans kinds were simultaneously present in the experimental data and EAMF was able to identify and measure all of them (AAr: 545 mu V x ms, 762 mu V x ms and 1382 mu V x ms; AAm: 5 mu V, 9 mu V and 7 mu V; for PWA, QRSA and TWA, respectively) and to discriminate TWA as the prevalent one (with the highest AAr). EAMF accurately identifies and measures all kinds of electrocardiographic alternans. EAMF may support determination of incremental clinical utility of PWA and QRSA with respect to TWA only.Cardiolog

Adenoviruses Expressing PDX-1, BETA2/NeuroD and MafA Induces the Transdifferentiation of Porcine Neonatal Pancreas Cell Clusters and Adult Pig Pancreatic Cells into Beta-Cells

BackgroundA limitation in the number of insulin-producing pancreatic beta-cells is a special feature of diabetes. The identification of alternative sources for the induction of insulin-producing surrogate beta-cells is a matter of profound importance. PDX-1/VP16, BETA2/NeuroD, and MafA overexpression have been shown to influence the differentiation and proliferation of pancreatic stem cells. However, few studies have been conducted using adult animal pancreatic stem cells.MethodsAdult pig pancreatic cells were prepared from the non-endocrine fraction of adult pig pancreata. Porcine neonatal pancreas cell clusters (NPCCs) were prepared from neonatal pigs aged 1-2 days. The dispersed pancreatic cells were infected with PDX-1/VP16, BETA2/NeuroD, and MafA adenoviruses. After infection, these cells were transplanted under the kidney capsules of normoglycemic nude mice.ResultsThe adenovirus-mediated overexpression of PDX-1, BETA2/NeuroD and MafA induced insulin gene expression in NPCCs, but not in adult pig pancreatic cells. Immunocytochemistry revealed that the number of insulin-positive cells in NPCCs and adult pig pancreatic cells was approximately 2.6- and 1.1-fold greater than those in the green fluorescent protein control group, respectively. At four weeks after transplantation, the relative volume of insulin-positive cells in the grafts increased in the NPCCs, but not in the adult porcine pancreatic cells.ConclusionThese data indicate that PDX-1, BETA2/NeuroD, and MafA facilitate the beta-cell differentiation of NPCCs, but not adult pig pancreatic cells. Therefore PDX-1, BETA2/NeuroD, and MafA-induced NPCCs can be considered good sources for the induction of pancreatic beta-cells, and may also have some utility in the treatment of diabetes

Changes in frequency of premature complexes and heart rate variability related to shift work

OBJECTIVES To investigate whether an increased risk of cardiovascular disease might be caused by increased arrhythmogeneity and by unfavourable changes in autonomic cardiac control the changes in the occurrence of premature complexes (PVCs) and in heart rate variability (HRV) were studied in subjects who started to work in shifts. METHODS1 Year changes in frequency of PVCs and HRV were measured in 49 shift workers and 22 control subjects working in daytime. All respondents were starting in a new job in integrated circuit or waste incinerator plants. RESULTSThe incidence of PVC increased significantly in shift workers over the 1 year follow up, compared with daytime workers. The frequency of ventricular extrasystoles increased in 48.9 f the shift workers, and in 27.3 f the daytime workers. The Spearman correlation coefficient between the number of nights worked and the change in PVCs was 0.33 (p=0.004). A small non-significant unfavourable change in HRV was found in both the shift and daytime workers. CONCLUSIONSA change in arrhythmogeneity, but not in cardiac autonomic control, might explain the increased risk of cardiovascular disease in shift worker

A pilot randomized controlled trial of omegaâ 3 fatty acid supplementation for the treatment of anxiety in adolescents with anorexia nervosa

ObjectiveTo evaluate the effectiveness and tolerability of omegaâ 3 polyunsaturated fatty acid (PUFA) supplementation for treatment of trait anxiety among adolescent females with restrictive anorexia nervosa (AN).MethodA pilot doubleâ blind, placeboâ controlled randomized trial of adolescent females with AN (Nâ =â 24) entering Partial Hospitalization Program (PHP) from January 2015 to February 2016. Participants were randomized to four daily PUFA (2,120â mg eicosapentaenoic acid/600â mg docosohexaenoic acid) or placebo capsules for 12â weeks. A 9â item questionnaire of side effect frequency assessed medication tolerability. The Beck Anxiety Inventoryâ Trait measured anxiety at baseline, 6, and 12â weeks. Linear mixed models evaluated associations between randomization group and study outcomes. Twentyâ two and 18 participants completed 6 and 12â weeks of data collection, respectively.ResultsMedication side effect scores were low and were not significantly different between randomization groups at Week 6 (pâ =â .20) or 12 (pâ =â .41). Mean trait anxiety score significantly (pâ <â .01) decreased from baseline to 12â weeks in both groups, and the rate of change over the course of time did not differ between omegaâ 3 PUFA and placebo groups (pâ =â .55).ConclusionOmegaâ 3 PUFA supplementation was well tolerated in adolescent females with AN. Although power to detect differences was limited, we found no evidence that omegaâ 3 PUFA benefited anxiety beyond nutritional restoration.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147040/1/eat22964_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147040/2/eat22964.pd

The Power of Exercise-Induced T-wave Alternans to Predict Ventricular Arrhythmias in Patients with Implanted Cardiac Defibrillator

ABSTRACT The power of exercise-induced T-wave alternans (TWA) to predict the occurrence of ventricular arrhythmias was evaluated in 67 patients with an implanted cardiac defibrillator (ICD). During the 4-year follow-up, electrocardiographic (ECG) tracings were recorded in a bicycle ergometer test with increasing workload ranging from zero (NoWL) to the patient&apos;s maximal capacity (MaxWL). After the follow-up, patients were classified as either ICD_Cases (n = 29), if developed ventricular tachycardia/fibrillation, or ICD_Controls (n = 38). TWA was quantified using our heart-rate adaptive match filter. Compared to NoWL, MaxWL was characterized by faster heart rates and higher TWA in both ICD_Cases (12−18 µ V vs. 20−39 µ V; P &lt; 0.05) and ICD_Controls (9-15 µ V vs. 20−32 µ V; P &lt; 0.05 ). Still, TWA was able to discriminate the two ICD groups during NoWL (sensitivity = 59−83%, specificity = 53−84%) but not MaxWL (sensitivity = 55−69%, specificity = 39−74%). Thus, this retrospective observational case-control study suggests that TWA&apos;s predictive power for the occurrence of ventricular arrhythmias could increase at low heart rates