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Introduction: Encephalopathy and delirium are common following coronavirus infection [1], and the associated neuroinflammation often results in long-term behavioral and cognitive impairment. Neurovirulent cytokines (NVC) are strongly implicated in the pathogenesis of coronavirus encephalopathy [2]. We hypothesized that characterizing the abnormal signaling in NVC exposed neurons will enable us to identify targets to treat encephalopathy and prevent its downstream effects. Method(s): We incubated primary mouse neocortical cultures in NVC known to be increased in coronavirus encephalopathy (TNF-alpha, IL-1beta, IL-6, IL-12 and IL-15). Using whole-cell patch clamp methods, we tested how neuronal function was impacted by 22-28-h exposure to NVC. Result(s): We found that NVC depolarized the resting membrane potential (RMP), reduced the firing threshold of neocortical neurons, and increased baseline spontaneous action potential (AP) firing. NVC altered the sensitivity (or input-output properties) of single neurons to changes in their microenvironment. Specifically, decreasing external Ca2+ and Mg2+ from physiological to low (1.1-0.2 mM) levels increased evoked AP firing in control, but not following exposure to NVC. AP firing threshold and spontaneous firing rates returned to control levels 1 h after NVC wash-out. However, the RMP and attenuated sensitivity of evoked APs to changes in the microenvironment remained persistently abnormal suggesting two distinct mechanisms were at play. Interestingly, hyperpolarizing the RMP reversed this altered response. Conclusion(s): Sustained exposure to NVC reversibly depolarizes neocortical neuronal RMP, altering excitability and the ability of neurons to respond to microenvironment changes. By characterizing the pathogenesis of the underlying changes in neuronal function in our model of coronavirus encephalopathy we will identify intervenable drug targets.
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Background Phospholamban (PLN), an inhibitor of sarcoplasmic reticulum (SR) Ca2+-ATPase, is a regulator of Ca2+ release during excitation-contraction coupling. We present a case of recurrent polymorphic ventricular tachycardia (PMVT)/ventricular fibrillation (VF) due to a PLN mutation. Case 38 year-old male presents after resuscitation following VF arrest. An ICD was implanted. Seven years later, he presented with VF storm requiring ventricular assist device support and he underwent catheter ablation of PVC triggers of VF arising from the moderator band. Because he had an ECG that was concerning for early repolarization syndrome, he was placed on quinidine and metoprolol. After an episode of VT in 2020 in the setting of COVID infection, whole genome sequencing was obtained and identified a pathogenic PLN mutation. PLN L39Ter has been associated with dilated and hypertrophic cardiomyopathy as well as sudden death. The patient has a history of normal left ventricular function and wall thickness by echocardiography. Decision-making Given the involvement of PLN on SR handling of Ca2+, flecainide may be a more effective therapy for the treatment of PMVT/VF in this patient. Conclusion PLN mutations have been associated with cardiomyopathies. This case illustrates a patient with the pathogenic PLN L39X variant with short-coupled PMVT with no imaging evidence of structural heart disease. Whether a more targeted therapy such as flecainide may be more effective in this patient remains to be determined. [Formula presented]Copyright © 2023 American College of Cardiology Foundation
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SESSION TITLE: Etiologies of Cardiovascular Disease Case Report Posters SESSION TYPE: Case Report Posters PRESENTED ON: 10/19/2022 12:45 pm - 01:45 pm INTRODUCTION: Troponin level (Tnl) is usually used as confirmation of acute myocardial infarction (AMI) and is a sensitive marker. It is usually increased within 2-3 hours after AMI. In most cases, increased in Tnl is associated with symptomatic chest pain, cardiac ischemia, chronic coronary syndromes, etc. It can also be elevated in other conditions without cardiac injuries, like critical illness: COVID infection, septic shock, acute stroke and burns. CASE PRESENTATION: A 72 y/o man with history of b/l internal carotid artery (ICA) stenosis (70% in R-ICA and 80-90% in L-ICA) underwent elective left trans-carotid artery revascularization (TCAR). He was transferred to ICU after an uneventful procedure, for monitoring. His history was significant for HTN, HLD, Meniere's disease, gout, prior CVA of L-frontal lacunar and R-PICA (posterior inferior cerebellar artery). Postop vitals: BP 114/60 mmHg, HR 65, RR 16, O2 sat 98%. Tnl increased to 1.95 and then declined (normal 0 - 0.4 ng/ml). He was AAOx4, and asymptomatic. Post-op serial EKGs: normal sinus rhythm with no ST/T wave changes. Echo: EF 60%, normal biventricular size and function. LDL <70, A1C 5.9, normal TSH, no CPK elevation. Other labs: normal, No new neurological deficits. He was continued on ASA, clopidogrel, metoprolol, amlodipine and lisinopril. His hospital stay was uneventful, and he was discharged on post-op day 3. DISCUSSION: Cardiac troponin complex has its distinct subunits according to their functions: highly conserved Ca2+ binding subunit (cTnC);actomyosin ATPase inhibitory subunit and tropomyosin binding subunit. They play the pivotal role in regulating myocardial muscle contraction and relaxation and demonstrate as sensitive biomarkers for the myocardial injuries. Interestingly, there are many other causes that lead to increased cardiac troponin level without remarkable myocardial injuries or ischemia. Elevated Tnl after TCAR procedure can also be due to its surgical complication of a chance of hypoperfusion during the procedure. Our patient's surgery was uneventful. In one randomized controlled trial, it is stated that the risk of having CVA and AMI is higher in carotid endarterectomy compared to revascularization in patients with carotid artery stenosis. Our patient did not have any post-op complication, and only had an idiopathic elevation of troponin. CONCLUSIONS: The role of Tnl plays an important role in confirmation of myocardial infarction or ischemia but it can be idiopathic. Unpublished data from our institution revealed no increase in troponin s/p TCAR after uneventful procedures. This is the first reported case presenting with elevated troponin level without any pertinent positive findings (EKG changes/symptoms). Maybe in uneventful TCAR procedure troponin should not be ordered? Reference #1: Defilippi, C.R., Tocchi, M., Parmar, R.J., Rosanio, S., Abreo, G., Potter, M.A., Runge, M.S., & Uretsky, B.F. (2000). Cardiac troponin T in chest pain unit patients without ischemic electrocardiographic changes: angiographic correlates and long-term clinical outcomes. Journal of the American College of Cardiology, 35 7, 1827-34. Reference #2: Gordon AM, Homsher E, Regnier M. Regulation of contraction in striated muscle. Physiol Rev. 2000 Apr;80(2):853-924. doi: 10.1152/physrev.2000.80.2.853. PMID: 10747208. Reference #3: Brott, T.G., Hobson, R.W., Howard, G., Roubin, G.S., Clark, W.M., Brooks, W., Mackey, A., Hill, M.D., Leimgruber, P.P., Sheffet, A.J., Howard, V.J., Moore, W.S., Voeks, J., Hopkins, L.N., Cutlip, D.E., Cohen, D.J., Popma, J.J., Ferguson, R.D., Cohen, S.N., Blackshear, J.L., Silver, F.L., Mohr, J.P., Lal, B.K., & Meschia, J.F. (2010). Stenting versus endarterectomy for treatment of carotid-artery stenosis. The New England journal of medicine, 363 1, 11-23. DISCLOSURES: No relevant relationships by Moses Bachan No relevant relationships by Zin Min Htet No relevant relationships by Z nobia Khan No relevant relationships by Zin Oo
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Rationale Delirium affects a majority of critically-ill patients, increasing mortality and dementia risk. The absence of effective therapy reversing neuronal changes in delirium emphasizes the need for greater understanding of delirium pathophysiology. Neuroinflammation represents a common pathway through which delirium-triggering diseases act. Glial cells sense systemic inflammation across the blood-brain barrier and become activated, releasing cytokines within the brain. In one disease model, systemic infection with neurovirulent coronaviruses caused delirium and specifically increased levels of TNF-α, IL-1β, IL-6, IL-12 and IL-15 in the mouse brain. Methods Here, we tested how neuronal function was affected in a coronavirus-induced neurovirulent cytokine (NVC) model of delirium. Using whole-cell patch clamp methods, we examined how single neuron excitability in murine primary neocortical cultures was impacted by 22-28 hour incubation in NVC. Results NVC treatment depolarized the resting membrane potential (RMP) compared to control (-65 ± 1.6 mV versus -73 ± 1 mV;P < 0.0001, n = 37 and 31 respectively) without affecting action potential characteristics. Delirium is often diagnosed due to altered responses to external stimuli. NVC exposure altered the sensitivity of neurons to changes in external Ca2+ and Mg2+ from physiological (1.1 mM, T1.1) to low (0.2 mM, T0.2) levels. The frequency of spontaneous firing was substantially increased following T0.2 application in control but not in NVC-treated neurons (p=0.026, ANOVA, control: 0.02 ± 0.01 Hz to 2.1 ± 1.2 Hz, n=16, p=0.046;NVC: 0.5 ± 0.4 Hz to 0.9 ± 0.3 Hz, n = 15, p=0.16). Consistent with this, evoked spiking following current injection was also observed in control but not NVC-treated neurons following the switch from T1.1 to T0.2 (P = 0.006, 2WRM ANOVA, Control: 3.9 ± 1.2 Hz vs. 8.5 ± 1.3 Hz n=37, p<0.0001;NVC: 4.8 ± 1.3 Hz vs. 4.5 ± 1.0 Hz, n=31, p=0.78). The attenuated excitability observed in NVC-treated neurons was reversed by hyperpolarization of the RMP. Evoked firing was substantially improved in NVC-treated cells after correcting the RMP (p =0.049, ANOVA, Control: 7.5 ± 1.8 Hz vs. 10 ± 2.5 Hz, n=15, p=0.25;NVC: 6.7 ± 2.2 Hz vs. 11.7 ± 2.8 Hz, n=16 p=0.01). Conclusion Our studies indicate that NVC-treated neurons have attenuated sensitivity to microenvironment changes. As these changes are reversible by correction of the RMP, further characterization of the underlying pathophysiological mechanism is essential to identify biologically plausible targets for delirium.
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BACKGROUND AND AIMS: Electrolyte abnormalities are common among patients with coronavirus disease 2019 (COVID-19). This study aims to investigate the electrolyte changes in severe and non-severe COVID-19 patients. Hypocalcaemia, hypomagnesaemia and hypoalbuminemia and their relationship with the severity of symptoms and prognosis will also be determined. METHOD: We enrolled 270 COVID-19 patients. Serum tests were taken from each patient on the day of admission to check the level of variables. Thereon, calcium, magnesium and phosphorus levels were measured twice a week and albumin levels were measured once a week. Variables such as PTH and 25 (OH) D were measured once at the beginning of the study. Other laboratory results like complete blood count, C-reactive protein and clinical data such as arterial blood oxygen levels, length of stay in the ICU and the treatment regimen were extracted from patients' medical records and history. Finally, patients were categorized as mild, moderate, severe and critical group based on the severity of the disease. The data analyses were carried out via SPSS software (version 21.0). RESULTS: Of 270 patients, 135 people (50%) were men. The mean age of patients was 46.7 years. Based on the severity of the disease, 91 patients had mild disease, 90 patients presented with moderate disease, 54 patients were in severe condition and 35 patients were critical. Hypocalcaemia (Ca2+ ≤8.6 mg/dL) was detected in 49 patients (18.1%) on admission. The mean of serum magnesium, phosphorus and albumin levels on admission was 2.2 ± 0.22 mEq/L, 3.39 ± 0.79 mg/dL and 4.49 ± 0.66g/dL, respectively. Phosphorus level was lower than 2.63 mg/dL in 11 patients (4.07%) and 43 patients (15.92%) had hypoalbuminemia. The mean 25(OH) D level was 32.92 ± 10.29 μg/L;therefore, 182 patients (67.40%) fall within the normal range (>30 μg/L). CONCLUSION: Patients with mild and moderate disease tend to develop hypocalcaemia, hypoalbuminemia and hypomagnesaemia more often than severe and critical COVID-19 patients during treatment. 25(OH) D deficiency rate was higher in the moderate group. Patients with hypocalcaemia during treatment had higher mortality than other patients. We recommend electrolytes be measured at initial presentation and serially monitored during hospitalization in order to establish timely and appropriate corrective actions and prevent the serious complications of the disease.
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Objective: Identify a plasma-based activity, or biomarker, that defines the mechanism(s) by which Covid-19 disease triggers excessive coagulation. Introduction: While acute respiratory syndrome is the fundamental feature of severe Covid-19 disease, having a high level of the coagulation biomarker D-dimer upon admission is associated with increased thrombosis and mortality. As such, hospitalized patients are often placed on anticoagulant heparins. How Covid-19 triggers excessive coagulation is unresolved. Sars-CoV-2 infection could expose existing tissue factor (TF) to blood or, via cytokines, induce TF expression on cells that are in direct contact with blood. Extracellular vesicles (EV) are lipid bound microparticles released by all types of healthy and damaged cell and Covid-19 patient plasma EV TF activity has been recently reported. Cellular activation and damage due to SARS-CoV-2 could also release polyanionic nucleic acids and polyphosphates and generate neutrophil extracellular traps as contact surfaces for clot formation. Methods: Study 1. We attempted to identify excessive coagulation pathway activities in Covid-19 plasma-based, Ca++-induced thrombin generation assays. Assays were performed in the absence and presence of selective extrinsic (TF) and intrinsic (contact activation) pathway inhibitors (n=296 plasma samples). D-dimer levels were also determined. In a smaller study, Covid-19 patient samples were collected directly into citrate or citrate plus corn trypsin inhibitor, then processed for analysis. Study 2. We conducted studies to evaluate the extent to which EV TF activity contributes to the Covid-19-associated coagulopathies. Plasma EVs were isolated and EV TF activity determined by the difference in FXa activity in the absence vs presence of anti-TF antibody. D-dimer and tissue factor pathway inhibitor a (TFPIa) antigen levels were measured. Data from 232 samples collected from 96 Covid-19 positive patients and 18 samples from 14 healthy controls were analyzed. For each study analysis, patient samples were organized into groups based on the disease severity outcomes as follows: hospitalization (Hospitalization;n=37);intensive care (ICU;n=16);mechanical ventilation (Ventilation;n=22);or fatality (Deceased;n=22). Result: Study 1. Covid-19 samples showed considerable thrombin generation variability with some samples failing to generate thrombin;pathway selective inhibitors reduced thrombin generation while heparinase treatment increased thrombin generation. Upon analysis, thrombin generation parameters showed no significant correlations to either D-dimer levels or disease severity. Instead, plasma prepared from blood collected directly into corn trypsin inhibitor revealed that contact activation that occurred post-sample collection dominates procoagulant activity. Study 2. Figure 1, shows EV TF activities, D-dimer and TFPIα levels obtained for Covid-19 samples, with data segregated based on disease severity outcomes. Statistically significant difference versus the Hospitalized group are shown. TFPIa levels were highest in heparin IV patients (24.4+1.5 nM) vs Heparin-SQ (12.8+0.9 nM) vs enoxaparin (10.8 +0.7 nM) (p value:<0.0001). It is known that heparin treatment increases circulating TFPIα, however an increase in TFPIα might also further increase circulating TF/FVIIa/XaTFPI inhibitory complex, which would dissociate in citrated plasma, and might account for the increase in EV TF in other studies. Conclusions: Contact activation that occurs post-sample collection is sufficient to obscure endogenous triggers of coagulation, if present, in Covid-19 patients' plasma. D-dimer and TFPIα strongly correlate with disease severity although the latter is likely affected by heparin treatment. The most severe Covid-19 patients with high D-dimer did not show detectible plasma EV TF activity. Plasma EV TF activity does not appear to adequately represent the mechanism responsible for elevated D-dimer levels in Covid-19 cases.
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Background: Cardiac injury associated with cytokine release occurs in almost 20% of SARS-CoV-2 positive patients during hospitalization and mortality is particularly high in these patients. Cardiac enzyme (e.g. troponin or creatinine kinase (CK)) elevations are a frequently reported finding, indicating myocardial damage and arrhythmias are the cause for ICU transfer in up to 12% of patients. However, the mechanistic role of COVID19 associated cytokine-storm for the concomitant cardiac dysfunction and associated arrhythmias is unclear. In addition, the role of anti-inflammatory therapy approaches to mitigate this cardiac dysfunction remains elusive. Methods: We investigated the effects of COVID19-associated inflammatory response on cardiac cellular function as well as its cardiac arrhythmogenic potential in rat and induced pluripotent stem cell derived cardiomyocytes (iPSc-CM). Moreover, we evaluated the therapeutic potential of the IL1-beta antagonist Canakinumab using state of the art in-vitro confocal and ratiometric high-throughput microscopy. Results: Isolated rat ventricular cardiomyocytes were exposed to control or COVID19 plasma from intensive care unit patients with severe ARDS and impaired cardiac function (LVEF 41±5%;1/3 of patients on veno-venous extracorporeal membrane oxygenation;CK 154±43 U/l). Cardiomyocytes showed decreased Ca2+ transient amplitudes and altered baseline Ca2+ concentrations leading to impaired cellular contractile function upon electrical field-stimulation and exposure to patient plasma (n=276 control and 359 COVID19 cells;Fura). In addition, we used iPSc-CM to explore the long-term effect of patient plasma on cardiac electrical and mechanical function in a translational setting (24h incubation;Fluo). In iPSc, spontaneous Ca2+ release events (i.e. Ca2+ waves and Ca2+ sparks) were more likely to occur upon incubation with COVID19 plasma and nuclear as well as cytosolic Ca2+ release were altered. Co-incubation with Canakinumab had no effect on pro-arrhythmogenic Ca2+ release or Ca2+ signaling during excitation-contraction coupling but influenced cellular automaticity upon prolonged electrical stimulation. Conclusion: Plasma derived from COVID19 patients exerts acute cardiodepressant and chronic pro-arrhythmogenic effects in rat and iPS-derived cardiomyocytes. Chronic co-incubation with Canakinumab had no beneficial effect on cellular Ca2+ signaling during excitation-contraction coupling.