56 results on '"El-Sherif N"'
Search Results
2. Long QT Syndrome and Torsade de Pointes
- Author
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El-Sherif, N., primary, Turitto, G., additional, and Boutjdir, M., additional
- Published
- 2018
- Full Text
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3. OBSOLETE: Long QT Syndrome and Torsade de Pointes
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El-Sherif, N., primary
- Published
- 2018
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4. P1468: SLEEP DISORDERED BREATHING IN SICKLE CELL DISEASE: RELATION TO PULMONARY HYPERTENSION AND STROKE
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Farghal, N. B. E.-D., primary, Tantawy, A., additional, Ebied, F. S. E., additional, El-Sherif, N., additional, Salah Eldeen, N., additional, Soliman, N., additional, and Makkeyah, S., additional
- Published
- 2022
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5. Cardiac Repolarization and Stem Cells: An Emerging Path Toward Precision Medicine
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El-Sherif, N, Gnecchi, M, Sala, L, Schwartz, P, Gnecchi M., Sala L., Schwartz P. J., El-Sherif, N, Gnecchi, M, Sala, L, Schwartz, P, Gnecchi M., Sala L., and Schwartz P. J.
- Abstract
The discovery of a genetic basis for cardiac repolarization disorders has introduced innovative technologies and concepts in the field of cardiac arrhythmias and has revolutionized the knowledge of these disorders as well as patients’ treatment. Conventional methodologies for the in vitro study of cardiac arrhythmias, only indirectly linked to the clinical phenotype, have started to age, and the information they can now provide suddenly appears limited. After the discovery that patient-specific cardiomyocytes can be derived, in virtually unlimited numbers, from pluripotent stem cells, we are now on the edge of another breakthrough with basic science laboratories heavily linked to clinical practice and offering tools with substantially higher translational capabilities. In this chapter, we present an excursus on the path that has led to the discovery, optimization, and implementation of pluripotent stem cell-derived cardiomyocytes for cardiac disease modeling. Then, we cover the major repolarization disorders with genetic bases whose phenotypes have been recapitulated and studied with these cardiomyocytes. Along this, we describe the techniques currently used to study repolarization disorders in vitro, and we offer a glimpse on what will come next in this field. Finally, we analyze the translational relevance of the powerful combination between genetics and stem cell-based approaches for cardiac arrhythmias, in a context of precision medicine.
- Published
- 2019
6. Effect of Nutmeg Administration on the Anterior Cingulate Cortex (Area 24a) of Adult Male Albino Rats and the Protective Role of Vitamin C: A Histological and Immunohistochemical Study
- Author
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M El-Sherif N
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General Medicine ,General Chemistry - Published
- 2017
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7. The kinetics of spontaneous calcium oscillations and arrhythmogenesis in the in vivo heart during ischemia/reperfusion
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Lakireddy, V, Lakkireddy, V, Bub, G, Baweja, P, Syed, A, Boutjdir, M, and El-Sherif, N
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Male ,medicine.medical_specialty ,Optics and Photonics ,Guinea Pigs ,Ischemia ,chemistry.chemical_element ,Action Potentials ,Myocardial Reperfusion Injury ,Calcium ,Ventricular tachycardia ,Afterdepolarization ,Heart Conduction System ,Physiology (medical) ,Internal medicine ,Optical mapping ,medicine ,Animals ,Calcium Signaling ,Membrane potential ,business.industry ,Arrhythmias, Cardiac ,medicine.disease ,Electrophysiology ,Disease Models, Animal ,Kinetics ,chemistry ,Ventricular fibrillation ,Cardiology ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background The correlation between spontaneous calcium oscillations (S-CaOs) and arrhythmogenesis has been investigated in a number of theoretical and experimental in vitro models. There is an obvious lack of studies that directly investigate how the kinetics of S-CaOs correlates with a specific arrhythmia in the in vivo heart. Objectives The purpose of the study is to investigate the correlation between the kinetics of S-CaOs and arrhythmogenesis in the intact heart using an experimental model of ischemia/reperfusion (I/R). Methods Perfused Langendorff guinea pig (GP) hearts were subjected to global I/R (10-15 minutes/10-15 minutes). The heart was stained with a voltage-sensitive dye (RH237) and loaded with a Ca 2+ indicator (Rhod-2 AM). Membrane voltage (Vm) and intracellular calcium transient (Ca i T) were simultaneously recorded with an optical mapping system of two 16 × 16 photodiode arrays. S-CaOs were considered to arise from a localized focal site within the mapped surface when these preceded the associated membrane depolarizations by 2-15 ms. Results In 135 episodes of ventricular arrhythmias from 28 different GP experiments, 23 were linked to S-CaOs that were considered to arise from or close to the mapped epicardial window. Self-limited or sustained S-CaOs had a cycle length of 130-430 ms and could trigger propagated ventricular depolarizations. Self-limited S-CaOs that followed the basic beat action potential (AP)/Ca i T closely resembled phase 3 early afterdepolarizations. Fast S-CaOs could remain confined to a localized site (concealed) or exhibit varying conduction patterns. This could manifest as (1) an isolated premature beat (PB), bigeminal, or trigeminal rhythm; (2) ventricular tachycardia (VT) when a regular 2:1 conduction from the focal site develops; or (3) ventricular fibrillation (VF) when a complex conduction pattern results in wave break and reentrant excitation. Conclusions The study examined, for the first time in the intact heart, the correlation between the kinetics of focal S-CaOs during I/R and arrhythmogenesis. S-CaOs may remain concealed or manifest as PBs, VT, or VF. A "benign looking" PB during I/R may represent "the tip of the iceberg" of an underlying potentially serious arrhythmic mechanism.
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- 2016
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8. 141 Frequency and Effect of Interruptions on Resident Workload in the Emergency Department
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Jones, D.D., primary, Forsyth, K.L., additional, Hawthorne, H.J., additional, El-Sherif, N., additional, Varghese, R.S., additional, Runkle, T., additional, Sunga, K., additional, Hellmich, T.R., additional, and Blocker, R.C., additional
- Published
- 2017
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9. Cardiac Repolarization and Stem Cells: An Emerging Path Toward Precision Medicine
- Author
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Luca Sala, Massimiliano Gnecchi, Peter J. Schwartz, El-Sherif, N, Gnecchi, M, Sala, L, and Schwartz, P
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Long QT syndrome ,Pluripotent stem cell ,Context (language use) ,Short qt syndrome ,030204 cardiovascular system & hematology ,Cardiac arrhythmia ,Sudden cardiac death ,03 medical and health sciences ,0302 clinical medicine ,Medicine ,Repolarization ,Brugada syndrome ,Induced pluripotent stem cell ,030304 developmental biology ,0303 health sciences ,business.industry ,Drug discovery ,Precision medicine ,medicine.disease ,3. Good health ,Electrophysiology ,Catecholaminergic polymorphic ventricular tachycardia ,Stem cell ,business ,Neuroscience ,Long qt syndrome - Abstract
The discovery of a genetic basis for cardiac repolarization disorders has introduced innovative technologies and concepts in the field of cardiac arrhythmias and has revolutionized the knowledge of these disorders as well as patients’ treatment. Conventional methodologies for the in vitro study of cardiac arrhythmias, only indirectly linked to the clinical phenotype, have started to age, and the information they can now provide suddenly appears limited. After the discovery that patient-specific cardiomyocytes can be derived, in virtually unlimited numbers, from pluripotent stem cells, we are now on the edge of another breakthrough with basic science laboratories heavily linked to clinical practice and offering tools with substantially higher translational capabilities. In this chapter, we present an excursus on the path that has led to the discovery, optimization, and implementation of pluripotent stem cell-derived cardiomyocytes for cardiac disease modeling. Then, we cover the major repolarization disorders with genetic bases whose phenotypes have been recapitulated and studied with these cardiomyocytes. Along this, we describe the techniques currently used to study repolarization disorders in vitro, and we offer a glimpse on what will come next in this field. Finally, we analyze the translational relevance of the powerful combination between genetics and stem cell-based approaches for cardiac arrhythmias, in a context of precision medicine.
- Published
- 2020
- Full Text
- View/download PDF
10. Calcium handling abnormalities increase arrhythmia susceptibility in DMSXL myotonic dystrophy type 1 mice.
- Author
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Cupelli M, Ginjupalli VKM, Reisqs JB, Sleiman Y, El-Sherif N, Gourdon G, Puymirat J, Chahine M, and Boutjdir M
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- Animals, Mice, Disease Models, Animal, Action Potentials drug effects, Ryanodine Receptor Calcium Release Channel metabolism, Ryanodine Receptor Calcium Release Channel genetics, Electrocardiography, Male, Phosphorylation, Mice, Inbred C57BL, Calcium Signaling, Flecainide pharmacology, Mice, Transgenic, Myotonic Dystrophy genetics, Myotonic Dystrophy metabolism, Myotonic Dystrophy physiopathology, Arrhythmias, Cardiac metabolism, Arrhythmias, Cardiac physiopathology, Arrhythmias, Cardiac genetics, Arrhythmias, Cardiac etiology, Calcium metabolism, Myocytes, Cardiac metabolism, Myocytes, Cardiac pathology
- Abstract
Background: Myotonic dystrophy type 1 (DM1) is a multiorgan disorder with significant cardiac involvement. ECG abnormalities, including arrhythmias, occur in 80 % of DM1 patients and are the second-most common cause of death after respiratory complications; however, the mechanisms underlying the arrhythmogenesis remain unclear. The objective of this study was to investigate the basis of the electrophysiological abnormalities in DM1 using the DMSXL mouse model., Methods: ECG parameters were evaluated at baseline and post flecainide challenge. Calcium transient and action potential parameters were evaluated in Langendorff-perfused hearts using fluorescence optical mapping. Calcium transient/sparks were evaluated in ventricular myocytes via confocal microscopy. Protein and mRNA levels for calcium handling proteins were evaluated using western blot and RT-qPCR, respectively., Results: DMSXL mice showed arrhythmic events on ECG including premature ventricular contractions and sinus block. DMSXL mice showed increased calcium transient time to peak without any change to voltage parameters. Calcium alternans and both sustained and non-sustained ventricular tachyarrhythmias were readily inducible in DMSXL mice. The confocal experiments also showed calcium transient alternans and increased frequency of calcium sparks in DMSXL cardiomyocytes. These calcium abnormalities were correlated with increased RyR2 phosphorylation without changes to the other calcium handling proteins., Conclusions: The DMSXL mouse model of DM1 exhibited enhanced arrhythmogenicity associated with abnormal intracellular calcium handling due to hyperphosphorylation of RyR2, pointing to RyR2 as a potential new therapeutic target in DM1 treatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2024
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11. Two methods of isolation of rat aortic smooth muscle cells with high yield.
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Lotfollahzadeh S, Jose A, Zarnaab Shafiq E, El Sherif N, Smith M, Han J, Seta F, and Chitalia V
- Abstract
Vascular smooth muscle cells (VSMCs) are an integral part of blood vessels and are the focus of intensive research in vascular biology, translational research, and cardiovascular diseases. Though immortalized vascular smooth muscle cell lines are available, their use is limited, underscoring the need for primary VSMCs. There are several methods for isolating primary cells from mice. However, the isolation method from rat blood vessels requires optimization, given the differences in the aorta of mice and rats. Here we compare two methods for VSMCs isolation from rats: enzymatic digestion and the "block" method. We observed a significantly higher yield of VSMCs using the enzymatic digestion method. We further confirmed that VSMCs expressed well-established VSMC-specific markers (calponin) with both methods and observed the persistence of this marker up to 9 passages, suggesting a continuation of the secretory phenotype of VSMCs. Overall, this work compares two methods and demonstrates a practical and effective method for isolating VSMCs from rat aorta, providing vascular biologists with a valuable and reliable experimental tool., (© The Author(s) 2024. Published by Oxford University Press.)
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- 2024
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12. Elevated Interleukin-6 Levels Are Associated With an Increased Risk of QTc Interval Prolongation in a Large Cohort of US Veterans.
- Author
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Lazzerini PE, Cupelli M, Cartocci A, Bertolozzi I, Salvini V, Accioli R, Salvadori F, Marzotti T, Verrengia D, Cevenini G, Bisogno S, Bicchi M, Donati G, Bernardini S, Laghi-Pasini F, Acampa M, Capecchi PL, El-Sherif N, and Boutjdir M
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- Male, Humans, Female, Interleukin-6, Risk Factors, Arrhythmias, Cardiac diagnosis, Arrhythmias, Cardiac epidemiology, Arrhythmias, Cardiac complications, Electrocardiography, Veterans, Long QT Syndrome diagnosis, Long QT Syndrome epidemiology, Long QT Syndrome etiology
- Abstract
Background: Although accumulating data indicate that IL-6 (interleukin-6) can promote heart rate-corrected QT interval (QTc) prolongation via direct and indirect effects on cardiac electrophysiology, current evidence comes from basic investigations and small clinical studies only. Therefore, IL-6 is still largely ignored in the clinical management of long-QT syndrome and related arrhythmias. The aim of this study was to estimate the risk of QTc prolongation associated with elevated IL-6 levels in a large population of unselected subjects., Methods and Results: An observational study using the Veterans Affairs Informatics and Computing Infrastructure was performed. Participants were US veterans who had an ECG and were tested for IL-6. Descriptive statistics and univariate and multivariate regression analyses were performed to study the relationship between IL-6 and QTc prolongation risk. Study population comprised 1085 individuals, 306 showing normal (<5 pg/mL), 376 moderately high (5-25 pg/mL), and 403 high (>25 pg/mL) IL-6 levels. Subjects with elevated IL-6 showed a concentration-dependent increase in the prevalence of QTc prolongation, and those presenting with QTc prolongation exhibited higher circulating IL-6 levels. Stepwise multivariate regression analyses demonstrated that increased IL-6 level was significantly associated with a risk of QTc prolongation up to 2 times the odds of the reference category of QTc (e.g. QTc >470 ms men/480 ms women ms: odds ratio, 2.28 [95% CI, 1.12-4.50] for IL-6 >25 pg/mL) regardless of the underlying cause. Specifically, the mean QTc increase observed in the presence of elevated IL-6 was quantitatively comparable (IL-6 >25 pg/mL:+6.7 ms) to that of major recognized QT-prolonging risk factors, such as hypokalemia and history of myocardial infarction., Conclusions: Our data provide evidence that a high circulating IL-6 level is a robust risk factor for QTc prolongation in a large cohort of US veterans, supporting a potentially important arrhythmogenic role for this cytokine in the general population.
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- 2024
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13. Editorial: The interaction of biotic and abiotic stresses.
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Pandey P, Gupta A, and El-Sherif N
- Abstract
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Published
- 2023
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14. Electrophysiological basis of cardiac arrhythmia in a mouse model of myotonic dystrophy type 1.
- Author
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Ginjupalli VKM, Cupelli M, Reisqs JB, Sleiman Y, El-Sherif N, Gourdon G, Puymirat J, Chahine M, and Boutjdir M
- Abstract
Introduction: Myotonic dystrophy type 1 (DM1) is a multisystemic genetic disorder caused by the increased number of CTG repeats in 3' UTR of Dystrophia Myotonia Protein Kinase (DMPK) gene. DM1 patients experience conduction abnormalities as well as atrial and ventricular arrhythmias with increased susceptibility to sudden cardiac death. The ionic basis of these electrical abnormalities is poorly understood. Methods: We evaluated the surface electrocardiogram (ECG) and key ion currents underlying the action potential (AP) in a mouse model of DM1, DMSXL, which express over 1000 CTG repeats. Sodium current (I
Na ), L-type calcium current (ICaL ), transient outward potassium current (Ito ), and APs were recorded using the patch-clamp technique. Results: Arrhythmic events on the ECG including sinus bradycardia, conduction defects, and premature ventricular and atrial arrhythmias were observed in DMSXL homozygous mice but not in WT mice. PR interval shortening was observed in homozygous mice while ECG parameters such as QRS duration, and QTc did not change. Further, flecainide prolonged PR, QRS, and QTc visually in DMSXL homozygous mice. At the single ventricular myocyte level, we observed a reduced current density for Ito and ICaL with a positive shift in steady state activation of L-type calcium channels carrying ICaL in DMSXL homozygous mice compared with WT mice. INa densities and action potential duration did not change between DMSXL and WT mice. Conclusion: The reduced current densities of Ito , and ICaL and alterations in gating properties in L-type calcium channels may contribute to the ECG abnormalities in the DMSXL mouse model of DM1. These findings open new avenues for novel targeted therapeutics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision, (Copyright © 2023 Ginjupalli, Cupelli, Reisqs, Sleiman, El-Sherif, Gourdon, Puymirat, Chahine and Boutjdir.)- Published
- 2023
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15. Contribution of cytokine-mediated prolongation of QTc interval to the multi-hit theory of Torsade de Pointes.
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Cupelli M, Ginjupalli VKM, Chen L, Capecchi PL, Lazzerini PE, Boutjdir M, and El-Sherif N
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- Animals, Guinea Pigs, Cytokines, Quetiapine Fumarate, Interleukin-6, Arrhythmias, Cardiac, Inflammation complications, Electrocardiography, Torsades de Pointes chemically induced, Hypokalemia, Long QT Syndrome chemically induced
- Abstract
Background: Torsade de pointes is a potentially lethal polymorphic ventricular tachyarrhythmia that can occur in the setting of long QT syndrome (LQTS). LQTS is multi-hit in nature and multiple factors combine their effects leading to increased arrhythmic risk. While hypokalemia and multiple medications are accounted for in LQTS, the arrhythmogenic role of systemic inflammation is increasingly recognized but often overlooked. We tested the hypothesis that the inflammatory cytokine interleukin(IL)-6 will significantly increase the incidence of arrhythmia when combined with other pro-arrhythmic conditions (hypokalemia and the psychotropic medication, quetiapine)., Methods: Guinea pigs were injected intraperitoneally with IL-6/soluble IL-6 receptor and QT changes were measured in vivo. Subsequently, hearts were cannulated via Langendorff perfusion for ex vivo optical mapping measurements of action potential duration (APD
90 ) and arrhythmia inducibility. Computer simulations (MATLAB) were performed to investigate IKr inhibition at varying IL-6 and quetiapine concentrations., Results: IL-6 prolonged QTc in vivo guinea pigs from 306.74 ± 7.19 ms to 332.60 ± 8.75 ms (n = 8, p = .0021). Optical mapping on isolated hearts demonstrated APD prolongation in IL-6- vs saline groups (3Hz APD90 :179.67 ± 2.47 ms vs 153.5 ± 7.86 ms, p = .0357). When hypokalemia was introduced, the APD90 increased to 195.8 ± 5.02 ms[IL-6] and 174.57 ± 10.7 ms[saline] (p = .2797), and when quetiapine was added to hypokalemia to 207.67 ± 3.03 ms[IL-6] and 191.37 ± 9.49 ms[saline] (p = .2449). After the addition of hypokalemia ± quetiapine, arrhythmia was induced in 75% of IL-6-treated hearts (n = 8), while in none of the control hearts (n = 6). Computer simulations demonstrated spontaneous depolarizations at ∼83% aggregate IKr inhibition., Conclusions: Our experimental observations strongly suggest that controlling inflammation, specifically IL-6, could be a viable and important route for reducing QT prolongation and arrhythmia incidence in the clinical setting., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Nabil El-Sherif reports financial support was provided by Narrows Institute for Biomedical Research and Education, Inc. Mohamed Boutjdir reports financial support was provided by Biomedical Laboratory Research & Development Service of Veterans Affairs Office of Research and Development. Mohamed Boutjdir reports financial support was provided by National Heart Lung and Blood Institute. Mohamed Boutjdir reports financial support was provided by US Department of Defense., (Published by Elsevier Inc.)- Published
- 2023
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16. Complexity and Outcome of Reoperations After the Ross Procedure in the Current Era.
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El Sherif N, Dearani JA, Connolly HM, Bagameri G, Pochettino A, Stulak JM, and Stephens EH
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- Humans, Adolescent, Young Adult, Adult, Middle Aged, Aortic Valve surgery, Reoperation, Retrospective Studies, Echocardiography, Transplantation, Autologous, Treatment Outcome, Follow-Up Studies, Pulmonary Valve transplantation, Aortic Valve Insufficiency surgery, Aortic Valve Stenosis surgery
- Abstract
Background: The Ross procedure has several advantages, but the need for reintervention is inevitable. The aim of this study was to examine the complexity and outcomes of reoperation after the Ross procedure., Methods: Retrospective chart review was performed of patients with a prior Ross procedure who underwent reoperation at our institution from September 1991 to January 2021. Demographic, echocardiographic, surgical, and perioperative data were collected. Descriptive statistical and regression analyses were performed., Results: A total of 105 patients underwent a reoperation at Mayo Clinic after the initial Ross procedure performed at our institution (n = 16; 16.2%) or elsewhere (n = 83; 83.8%). Mean age at the Ross procedure was 27 ± 17 years, and mean age at reoperation at our institution was 37 ± 19 years. Indications for surgical procedure varied, but 64% had autograft regurgitation as 1 of their indications for reoperation. Autograft interventions were performed in 78 patients (74.2%). Pulmonary valve or conduit replacement was performed in 56 patients (53.3%). Double root replacement was performed in 11 patients (10.5%). Aortic reconstruction was performed in 37 patients (38.4%). There were 5 early deaths (5%). During a median follow-up of 6.25 years (3 months-24 years), late deaths occurred in 14 patients (13.1%). Patients with ejection fraction <30% on preoperative echocardiography had shorter duration between the Ross procedure and subsequent reoperation (P = .03)., Conclusions: Reoperations after the Ross procedure are performed for a wide range of indications, with most due to autograft dysfunction. The number of early deaths is not low. Reoperation after the Ross procedure should be advised before left ventricular systolic dysfunction., (Copyright © 2023 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
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- 2023
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17. Sleep disordered breathing and its relation to stroke and pulmonary hypertension in children with sickle cell disease: a single-center cross-sectional study.
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Tantawy A, El-Sherif N, Makkeyah S, Eldeen NS, Farghal NBE, Soliman N, and Ebeid FSE
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- Adolescent, Humans, Male, Child, Female, Cross-Sectional Studies, Hypertension, Pulmonary diagnostic imaging, Hypertension, Pulmonary epidemiology, Hypertension, Pulmonary etiology, Sleep Apnea Syndromes epidemiology, Sleep Apnea Syndromes etiology, Sleep Apnea, Obstructive complications, Sleep Apnea, Obstructive epidemiology, Anemia, Sickle Cell complications, Anemia, Sickle Cell epidemiology, Stroke diagnostic imaging, Stroke epidemiology, Stroke etiology
- Abstract
Sleep disordered breathing (SDB) is a common underdiagnosed sequela of sickle cell disease (SCD) that has been linked to the frequency of vaso-occlusive crises. To determine the frequency of SDB in children with SCD and its association to SCD-related complications, thirty children and adolescents with SCD at their steady state underwent clinical, laboratory, and radiological assessment using transcranial duplex (TCD) and echo assessment of tricuspid regurge velocity (TRV). All participants had an overnight polysomnography after completing the modified STOP-Bang questionnaire. The mean age of the studied cohort was 10.2 years, with male: female ratio 1.7:1. Six children (20%) had high-risk for obstructive sleep apnea (OSA), while nine (30%) were at intermediate risk. Sleep apnea defined as apnea (AHI) > 1 event/hour was found among 18/30 (60%) subjects (14 males and 4 females). Children with AHI > 5 (moderate to severe OSA) had significantly higher TRV (p = 0.007) and left MCA flow velocity (p = 0.049) when compared to those with AHI < 5. Children with AHI > 5 were at higher risk of OSA according to the modified STOP-Bang questionnaire (p = 0.02). AHI positively correlated with TRV (r = 0.53, p = 0.003), right MCA flow velocity (r = 0.45, p = 0.013), and left MCA flow velocity (r = 0.55, p = 0.002), and negatively correlated to BMI-SDS (r = - 0.48, p = 0.008). The high frequency of OSA in the studied cohort with SCD and its association with increasing risk of PH and TCD changes highlights the importance of early detection and management of OSA in children with SCD., (© 2023. The Author(s).)
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- 2023
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18. Surgical repair of discontinuous right pulmonary artery utilising an autologous main pulmonary artery flap: a case report and literature review.
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El Sherif N, Cetta F, and Stephens EH
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- Cardiac Catheterization, Constriction, Pathologic, Humans, Infant, Male, Transplantation, Autologous, Pulmonary Artery diagnostic imaging, Pulmonary Artery surgery, Surgical Flaps
- Abstract
This is a case of an infant with unilateral discontinuous right pulmonary artery. Cardiac catheterisation with pulmonary wedge injection diagnosed the anomaly and aided in surgical planning. The patient underwent semi-autologous surgical repair utilising an autologous main pulmonary artery flap. One month following discharge, he underwent successful balloon dilation of the residual stenosis and was discharged the same day.
- Published
- 2021
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19. Treatment outcomes for childhood acute lymphoblastic leukemia in low-middle income country before minimal residual disease risk stratification.
- Author
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Makkeyah S, Manzour A, Tantawy A, Mohamed A, Ebeid F, El-Sherif N, Abd El-Ghany S, Shawiesh M, Ali H, Sayed S, and Ragab I
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- Disease-Free Survival, Humans, Infant, Neoplasm, Residual, Prognosis, Risk Assessment, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Precursor Cell Lymphoblastic Leukemia-Lymphoma drug therapy, Precursor Cell Lymphoblastic Leukemia-Lymphoma epidemiology
- Abstract
Background: Outcome of childhood acute lymphoblastic leukemia (ALL) in low- and middle-income countries is lagging in many aspects including diagnosis, risk stratification, access to treatment and supportive care., Objective: to report the outcome of childhood ALL at Ain Shams University Children's Hospitals with the use of risk-based protocols before the implementation of minimal residual disease technology and to evaluate the use of double delayed intensification (DDI) in standard risk patients., Methods: Two hundred and twenty patients with ALL diagnosed between January 2005 and December 2014 were included in the study. Patients were treated according to a modified CCG 1991 and 1961 for standard and high risk respectively. Patients were stratified into three risk groups: standard risk (SR), high-risk standard arm (HR-SA), and high-risk augmented arm (HR-AA)., Results: Among the whole cohort, the 10-year event-free survival (EFS) and overall survival (OS) were 78.1% and 84.3% respectively. Patients with Pre-B immunophenotype (IPT) had significantly better outcome than T-cell IPT (EFS 82.0% versus 58.6%, p < 0.001; OS 86.9% versus 69%, p = 0.003 for Pre-B and T-cell respectively). Among the SR group, patients treated with single delayed intensification (SDI) had comparable EFS and OS rates when compared to patients treated with DDI with EFS 82.4% versus 87.5%, p = 0.825 and OS 88.2% versus 93.5%, p = 0.638 for SDI and DDI groups, respectively., Conclusion: The use of risk-based protocol with simple laboratory techniques resulted in acceptable survival outcome in resource limited settings. The use of double delayed intensification showed no survival advantage in patients with standard risk., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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20. Unravelling Atrioventricular Block Risk in Inflammatory Diseases: Systemic Inflammation Acutely Delays Atrioventricular Conduction via a Cytokine-Mediated Inhibition of Connexin43 Expression.
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Lazzerini PE, Acampa M, Cupelli M, Gamberucci A, Srivastava U, Nanni C, Bertolozzi I, Vanni F, Frosali A, Cantore A, Cartocci A, D'Errico A, Salvini V, Accioli R, Verrengia D, Salvadori F, Dokollari A, Maccherini M, El-Sherif N, Laghi-Pasini F, Capecchi PL, and Boutjdir M
- Subjects
- Animals, Atrioventricular Node, Cytokines, Guinea Pigs, Humans, Inflammation, Interleukin-6, Leukocytes, Mononuclear, Atrioventricular Block, Connexin 43
- Abstract
Background Recent data suggest that systemic inflammation can negatively affect atrioventricular conduction, regardless of acute cardiac injury. Indeed, gap-junctions containing connexin43 coupling cardiomyocytes and inflammation-related cells (macrophages) are increasingly recognized as important factors regulating the conduction in the atrioventricular node. The aim of this study was to evaluate the acute impact of systemic inflammatory activation on atrioventricular conduction, and elucidate underlying mechanisms. Methods and Results We analyzed: (1) the PR-interval in patients with inflammatory diseases of different origins during active phase and recovery, and its association with inflammatory markers; (2) the existing correlation between connexin43 expression in the cardiac tissue and peripheral blood mononuclear cells (PBMC), and the changes occurring in patients with inflammatory diseases over time; (3) the acute effects of interleukin(IL)-6 on atrioventricular conduction in an in vivo animal model, and on connexin43 expression in vitro. In patients with elevated C-reactive protein levels, atrioventricular conduction indices are increased, but promptly normalized in association with inflammatory markers reduction, particularly IL-6. In these subjects, connexin43 expression in PBMC, which is correlative of that measured in the cardiac tissue, inversely associated with IL-6 changes. Moreover, direct IL-6 administration increased atrioventricular conduction indices in vivo in a guinea pig model, and IL-6 incubation in both cardiomyocytes and macrophages in culture, significantly reduced connexin43 proteins expression. Conclusions The data evidence that systemic inflammation can acutely worsen atrioventricular conduction, and that IL-6-induced down-regulation of cardiac connexin43 is a mechanistic pathway putatively involved in the process. Though reversible, these alterations could significantly increase the risk of severe atrioventricular blocks during active inflammatory processes.
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- 2021
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21. Obstructive Sleep Apnea and Cardiovascular Disease: A Scientific Statement From the American Heart Association.
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Yeghiazarians Y, Jneid H, Tietjens JR, Redline S, Brown DL, El-Sherif N, Mehra R, Bozkurt B, Ndumele CE, and Somers VK
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- Animals, Cardiovascular Diseases diagnosis, Cardiovascular Diseases etiology, Comorbidity, Disease Management, Disease Susceptibility, Humans, Mass Screening, Public Health Surveillance, Research trends, Risk Assessment, Risk Factors, Sleep Apnea, Obstructive diagnosis, Sleep Apnea, Obstructive etiology, Symptom Assessment, Cardiovascular Diseases complications, Cardiovascular Diseases epidemiology, Sleep Apnea, Obstructive complications, Sleep Apnea, Obstructive epidemiology
- Abstract
Obstructive sleep apnea (OSA) is characterized by recurrent complete and partial upper airway obstructive events, resulting in intermittent hypoxemia, autonomic fluctuation, and sleep fragmentation. Approximately 34% and 17% of middle-aged men and women, respectively, meet the diagnostic criteria for OSA. Sleep disturbances are common and underdiagnosed among middle-aged and older adults, and the prevalence varies by race/ethnicity, sex, and obesity status. OSA prevalence is as high as 40% to 80% in patients with hypertension, heart failure, coronary artery disease, pulmonary hypertension, atrial fibrillation, and stroke. Despite its high prevalence in patients with heart disease and the vulnerability of cardiac patients to OSA-related stressors and adverse cardiovascular outcomes, OSA is often underrecognized and undertreated in cardiovascular practice. We recommend screening for OSA in patients with resistant/poorly controlled hypertension, pulmonary hypertension, and recurrent atrial fibrillation after either cardioversion or ablation. In patients with New York Heart Association class II to IV heart failure and suspicion of sleep-disordered breathing or excessive daytime sleepiness, a formal sleep assessment is reasonable. In patients with tachy-brady syndrome or ventricular tachycardia or survivors of sudden cardiac death in whom sleep apnea is suspected after a comprehensive sleep assessment, evaluation for sleep apnea should be considered. After stroke, clinical equipoise exists with respect to screening and treatment. Patients with nocturnally occurring angina, myocardial infarction, arrhythmias, or appropriate shocks from implanted cardioverter-defibrillators may be especially likely to have comorbid sleep apnea. All patients with OSA should be considered for treatment, including behavioral modifications and weight loss as indicated. Continuous positive airway pressure should be offered to patients with severe OSA, whereas oral appliances can be considered for those with mild to moderate OSA or for continuous positive airway pressure-intolerant patients. Follow-up sleep testing should be performed to assess the effectiveness of treatment.
- Published
- 2021
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22. Proton Pump Inhibitors Directly Block hERG-Potassium Channel and Independently Increase the Risk of QTc Prolongation in a Large Cohort of US Veterans.
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Lazzerini PE, Cartocci A, Qu YS, Saponara S, Furini S, Fusi F, Fabris F, Gamberucci A, El-Sherif N, Cevenini G, Pettini F, Laghi-Pasini F, Acampa M, Bertolozzi I, Capecchi PL, Lazaro D, and Boutjdir M
- Subjects
- Cells, Cultured, Female, Humans, Incidence, Long QT Syndrome physiopathology, Male, Middle Aged, Treatment Outcome, United States epidemiology, ERG1 Potassium Channel metabolism, Electrocardiography, Long QT Syndrome drug therapy, Proton Pump Inhibitors therapeutic use, Veterans
- Abstract
[Figure: see text].
- Published
- 2021
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23. Risk of QTc Interval Prolongation Associated With Circulating Anti-Ro/SSA Antibodies Among US Veterans: An Observational Cohort Study.
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Lazzerini PE, Cevenini G, Qu YS, Fabris F, El-Sherif N, Acampa M, Cartocci A, Laghi-Pasini F, Capecchi PL, Boutjdir M, and Lazaro D
- Subjects
- Biomarkers blood, Cross-Sectional Studies, Female, Follow-Up Studies, Humans, Incidence, Long QT Syndrome epidemiology, Long QT Syndrome immunology, Long QT Syndrome physiopathology, Male, Middle Aged, Retrospective Studies, Risk Factors, United States epidemiology, Antibodies, Antinuclear blood, Electrocardiography, Heart Rate physiology, Long QT Syndrome blood, Veterans
- Abstract
Background Anti-Sjögren's syndrome-related antigen A-antibodies (anti-Ro/SSA-antibodies) are responsible for a novel form of acquired long-QT syndrome, owing to autoimmune-mediated inhibition of cardiac human ether-a-go-go-related gene-potassium channels. However, current evidence derives only from basic mechanistic studies and relatively small sample-size clinical investigations. Hence, the aim of our study is to estimate the risk of QTc prolongation associated with the presence of anti-Ro/SSA-antibodies in a large population of unselected subjects. Methods and Results This is a retrospective observational cohort study using the Veterans Affairs Informatics and Computing Infrastructure. Participants were veterans who were tested for anti-Ro/SSA status and had an ECG. Descriptive statistics and univariate and multivariate logistic regression analyses were performed to identify risk factors for heart rate-corrected QT interval (QTc) prolongation. The study population consisted of 7339 subjects (61.4±12.2 years), 612 of whom were anti-Ro/SSA-positive (8.3%). Subjects who were anti-Ro/SSA-positive showed an increased prevalence of QTc prolongation, in the presence of other concomitant risk factors (crude odds ratios [OR], 1.67 [1.26-2.21] for QTc >470/480 ms; 2.32 [1.54-3.49] for QTc >490 ms; 2.77 [1.66-4.60] for QTc >500 ms), independent of a connective tissue disease history. Adjustments for age, sex, electrolytes, cardiovascular risk factors/diseases, and medications gradually attenuated QTc prolongation estimates, particularly when QT-prolonging drugs were added to the model. Nevertheless, stepwise-fully adjusted OR for the higher cutoffs remained significantly increased in anti-Ro/SSA-positive subjects, particularly for QTc >500 ms (2.27 [1.34-3.87]). Conclusions Anti-Ro/SSA-antibody positivity was independently associated with an increased risk of marked QTc prolongation in a large cohort of US veterans. Our data suggest that within the general population individuals who are anti-Ro/SSA-positive may represent a subgroup of patients particularly predisposed to ventricular arrhythmias/sudden cardiac death.
- Published
- 2021
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24. Voltage/Calcium Uncoupling Underlies Sustained Torsade de Pointes Ventricular Tachyarrhythmia in an Experimental Model of Long QT Syndrome.
- Author
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Himel HD, Cupelli M, Boutjdir M, and El-Sherif N
- Abstract
Background: Clinical experience showed that the majority of Torsade de Pointes (TdP) ventricular tachyarrhythmia (VT) in patients with long QT syndrome (LQTS) are self-terminating (ST), but the few that are non-self-terminating (NST) are potentially fatal. A paramount issue in clinical arrhythmology is to understand the electrophysiological mechanism of ST vs. NST TdP VT., Methods: We investigated the electrophysiological mechanism of ST vs. NST TdP VT in the guinea pig Anthopleurin-A experimental model of LQTS, a close surrogate model of congenital LQT3. We utilized simultaneous optical recordings of membrane voltage (V
m ) and intracellular calcium (Cai ) and a robust analytical method based on spatiotemporal entropy difference (Ed ) to investigate the hypothesis that early Vm /Cai uncoupling during TdP VT can play a primary role in perpetuation of VT episodes., Results: We analyzed a total of 35 episodes of TdP VT from 14 guinea pig surrogate models of LQTS, including 23 ST and 12 NST VTs. Ed values for NST VT were significantly higher than Ed values for ST VT. Analysis of wave front topology during the early phase of ST VT showed the Cai wave front following closely Vm wave front consistent with a lower degree of Ed . In contrast, NST VT was associated with uncoupling of Vm /Cai wave fronts during the first 2 or 3 cycles of VT associated with early wave break propagation pattern., Conclusions: Utilizing a robust analytical method we showed that, in comparison to ST TdP VT, NST VT was consistently predated by early uncoupling of Vm /Cai that destabilized wave front propagation and can explain a sustained complex reentrant excitation pattern., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Himel, Cupelli, Boutjdir and El-Sherif.)- Published
- 2021
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25. Genetic Diversity among Selected Medicago sativa Cultivars Using Inter-Retrotransposon-Amplified Polymorphism, Chloroplast DNA Barcodes and Morpho-Agronomic Trait Analyses.
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Badr A, El-Sherif N, Aly S, Ibrahim SD, and Ibrahim M
- Abstract
Alfalfa ( Medicago sativa L.) is a major forage crop of family Fabaceae and is frequently cultivated in Egypt. The present study is concerned with the genetic discrimination of fifteen alfalfa cultivars from three different countries (Egypt, Australia, and USA) using two molecular approaches: inter-retrotransposon-amplified polymorphism (IRAP) markers and two chloroplast DNA barcodes mat K and the trn H in addition to the analysis of fifteen morpho-agronomic traits. The genetic relatedness, based on analysis of IRAP marker polymorphism and produced using eleven primers by clustering via principal component analysis (PCA) and multivariate heatmap biostatistical methods differentiated the two Egyptian cultivars EGY1-Ismailia1 and EGY2-Nubaria1 from the three Australian and seven American cultivars, with some distinction of the cv. USA6-SW9720 and cv. AUS4-SuperFast. The results were also supported by the sequence analysis of the mat K and the trn H genes on the genetic relatedness between eight cultivars. Moreover, it might be suggested that breeding lines from M. sativa cultivars may provide novel insights and a better understanding of the domestication of M. sativa genetic diversity. The classification of the eight cultivars, as revealed by morpho-agronomic traits, confirmed the close genetic relationship between the two Egyptian cultivars and indicated some resemblance between them and the AUS2-Siri Nafa, whereas the two American cultivars, USA1-Super supreme and USA4-Cuf101, were clearly isolated from a cluster of other three cultivars USA7-SW9628, USA8-Magna901, and USA9-Perfect. The results are useful sources of genetic information for future breeding programs in crop development and open new possibilities of producing M. sativa lines harboring high forage quality, productivity, and resistance to biotic and abiotic stresses.
- Published
- 2020
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26. Androgen Deprivation Therapy for Prostatic Cancer in Patients With Torsades de Pointes.
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Lazzerini PE, Bertolozzi I, Acampa M, Cantara S, Castagna MG, Pieragnoli L, D'Errico A, Rossi M, Bisogno S, El-Sherif N, Boutjdir M, Laghi-Pasini F, and Capecchi PL
- Abstract
Background: Men normally have shorter heart rate-corrected QT interval (QTc) than women, at least in part due to accelerating effects of testosterone on ventricular repolarization. Accumulating data suggest that androgen-deprivation therapy (ADT) used for the treatment of prostatic cancer, may increase Torsades de Pointes (TdP) risk by prolonging QTc. However, the evidence for such an association is currently limited to few case reports, in most cases deriving from the analysis of uncontrolled sources such as pharmacovigilance databases., Objective: To better determine the clinical impact of ADT on TdP development, we examined the prevalence of this therapy in a consecutive cohort of 66 TdP patients, prospectively collected over a ~10 years period., Methods and Results: We found and described four patients who were under ADT for prostatic cancer when TdP occurred, and in two cases degenerated to cardiac arrest. Notably, in this unselected population, ADTs unexpectedly represented the second most frequently administered QT-prolonging medication in males (4/24, 17%), after amiodarone. Moreover, in the ADT patients, a blood withdrawal was performed within 24 h from TdP/marked QTc prolongation occurrence and circulating concentration of androgens and gonadothropins were measured. As expected, all cases showed markedly reduced testosterone levels (total, free, and available)., Conclusion: We provide evidence that a significant proportion of patients developing TdP were under treatment with ADT for prostatic cancer, thus confirming the clinical relevance of previous pharmacovigilance signals. An accurate assessment of the arrhythmic risk profile should be included in the standard of care of prostatic cancer patients before starting ADT., (Copyright © 2020 Lazzerini, Bertolozzi, Acampa, Cantara, Castagna, Pieragnoli, D’Errico, Rossi, Bisogno, El-Sherif, Boutjdir, Laghi-Pasini and Capecchi.)
- Published
- 2020
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27. Autoimmune and inflammatory K + channelopathies in cardiac arrhythmias: Clinical evidence and molecular mechanisms.
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Capecchi PL, Laghi-Pasini F, El-Sherif N, Qu Y, Boutjdir M, and Lazzerini PE
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- Arrhythmias, Cardiac metabolism, Arrhythmias, Cardiac physiopathology, Channelopathies metabolism, Channelopathies physiopathology, DNA Mutational Analysis, Humans, Potassium Channels metabolism, Arrhythmias, Cardiac genetics, Autoimmunity, Channelopathies genetics, DNA genetics, Mutation, Potassium Channels genetics
- Abstract
Cardiac K
+ channelopathies account for a significant proportion of arrhythmias and sudden cardiac death (SCD) in subjects without structural heart disease. It is well recognized that genetic defects are key factors in many cases, and in practice, the term cardiac channelopathies currently coincides with inherited cardiac channelopathies. However, mounting evidence demonstrate that not only genetic alterations but also autoimmune and inflammatory factors can cause cardiac K+ -channel dysfunction and arrhythmias in the setting of a structurally normal heart. In particular, it has been demonstrated that specific autoantibodies as well as inflammatory cytokines can modulate expression and/or function of different K+ channels in the heart, resulting in a disruption of the cardiac action potential and arrhythmias/sudden cardiac death. Awareness about the existence of these newly recognized forms is essential to identify and adequately manage affected patients. In the present review, we focus on autoimmune and inflammatory K+ channelopathies as a novel mechanism for cardiac arrhythmias and analyze the recent advancements in this topic, providing complementary basic, clinical, and population health perspectives., (Copyright © 2019 Heart Rhythm Society. All rights reserved.)- Published
- 2019
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28. Role of spatial dispersion of repolarization in reentry around a functional core versus reentry around a fixed anatomical core.
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Himel HD, Cupelli M, Gantt M, Boutjdir M, and El-Sherif N
- Subjects
- Animals, Animals, Newborn, Cells, Cultured, Fluorescence, Intercellular Signaling Peptides and Proteins, Models, Animal, Rats, Rats, Sprague-Dawley, Voltage-Sensitive Dye Imaging methods, Myocytes, Cardiac physiology
- Abstract
Introduction: Successful initiation of spiral wave reentry in the neonatal rat ventricular myocyte (NRVM) monolayer implicitly assumes the presence of spatial dispersion of repolarization (DR), which is difficult to quantify. We recently introduced a NRVM monolayer that utilizes anthopleurin-A to impart a prolonged plateau to the NRVM action potential. This was associated with a significant degree of spatial DR that lends itself to accurate quantification., Methods and Results: We utilized the monolayer and fluorescence optical mapping of intracellular calcium transients (F
Cai ) to systematically study and compare the contribution of spatial dispersion of the duration of FCai (as a surrogate of DR) to induction of spiral wave reentry around a functional core versus reentry around a fixed anatomical obstacle. We show that functional reentry could be initiated by a premature stimulus acting on a substrate of spatial DR resulting in a functional line of propagation block. Subsequent wave fronts circulated around a central core of functional obstacle created by sustained depolarization from the circulating wave front. Both initiation and termination of spiral wave reentry around an anatomical obstacle consistently required participation of a region of functional propagation block. This region was similarly based on spatial DR. Spontaneous termination of spiral wave reentry also resulted from block in the functional component of the circuit obstacle, usually preceded by beat-to-beat slowing of propagation., Conclusions: The study demonstrates the critical contribution of DR to spiral wave reentry around a purely functional core as well as reentry around a fixed anatomical core., (© 2019 Wiley Periodicals, Inc.)- Published
- 2019
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29. Autoimmune Calcium Channelopathies and Cardiac Electrical Abnormalities.
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Qu YS, Lazzerini PE, Capecchi PL, Laghi-Pasini F, El Sherif N, and Boutjdir M
- Abstract
Patients with autoimmune diseases are at increased risk for developing cardiovascular diseases, and abnormal electrocardiographic findings are common. Voltage-gated calcium channels play a major role in the cardiovascular system and regulate cardiac excitability and contractility. Particularly, by virtue of their localization and expression in the heart, calcium channels modulate pace making at the sinus node, conduction at the atrioventricular node and cardiac repolarization in the working myocardium. Consequently, emerging evidence suggests that calcium channels are targets to autoantibodies in autoimmune diseases. Autoimmune-associated cardiac calcium channelopathies have been recognized in both sinus node dysfunction atrioventricular block in patients positive for anti-Ro/La antibodies, and ventricular arrhythmias in patients with dilated cardiomyopathy. In this review, we discuss mechanisms of autoimmune-associated calcium channelopathies and their relationship with the development of cardiac electrical abnormalities.
- Published
- 2019
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30. Acquired Long QT Syndrome and Electrophysiology of Torsade de Pointes.
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El-Sherif N, Turitto G, and Boutjdir M
- Abstract
Congenital long QT syndrome (LQTS) has been the most investigated cardiac ion channelopathy. Although congenital LQTS remains the domain of cardiologists, cardiac electrophysiologists and specialised centres, the much more frequently acquired LQTS is the domain of physicians and other members of healthcare teams required to make therapeutic decisions. This paper reviews the electrophysiological mechanisms of acquired LQTS, its ECG characteristics, clinical presentation, and management. The paper concludes with a comprehensive review of the electrophysiological mechanisms of torsade de pointes., Competing Interests: Disclosure: The authors have no conflicts of interest to declare.
- Published
- 2019
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31. Sweating the Little Things: Tourniquet Application Efficacy in Two Models of Pediatric Limb Circumference.
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El-Sherif N, Lowndes B, Franz W, Hallbeck MS, Belau S, and Sztajnkrycer MD
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- Child, Preschool, Equipment Design standards, Hemorrhage prevention & control, Hemorrhage therapy, Humans, Infant, Military Medicine methods, Military Medicine standards, Pediatrics instrumentation, Pediatrics methods, Self Efficacy, Tourniquets trends, Anthropometry methods, Extremities pathology, Tourniquets standards
- Abstract
Background: Current military recommendations include the use of tourniquets (TQ) in appropriate pediatric trauma patients. Although the utility of TQs has been well documented in adult patients, the efficacy of TQ application in pediatric patients is less clear. The current study attempted to identify physical constraints for TQ use in two simulated pediatric limb models., Methods: Five different TQ (Combat Application Tourniquet (CAT) Generation 6 and Generation 7, SOFTT (SOF Tactical Tourniquet), SOFTT-W (SOF Tactical Tourniquet - Wide), SWAT-T (Stretch Wrap and Tuck - Tourniquet) and a trauma dressing were evaluated in two simulated pediatric limb models. Model one employed four cardiopulmonary resuscitation (CPR) manikins simulating infant (Simulaids SaniBaby), 1 year (Gaumard HAL S3004), and 5 years (Laerdal Resusci Junior, Gaumard HAL S3005). Model two utilized polyvinyl chloride (PVC) piping with circumferences ranging from 4.25" to 16.5". Specific end-points included tightness of the TQ and ability to secure the windlass (where applicable)., Results: In both models, the ability to successfully apply and secure the TQ depended upon the simulated limb circumference. In the 1-year-old CPR manikin, all windlass TQs failed to tighten on the upper extremity, while all TQs successfully tightened at the high leg and mid-thigh. With the exception of the CAT7 and the SOFTT-W at the mid-thigh, no windlass TQ was successfully tightened at any extremity location on the infant. The SWAT-T was successfully tightened over all sites of all CPR manikins except the infant. No windlass TQ was able to tighten on PVC pipe 5.75" circumference or smaller (age < 24 months upper extremity). All windlass TQs were tightened and secured on the 13.25" and 15.5" circumference PVC pipes (age 7-12 years lower extremity, age >13 years upper extremity). The SWAT-T was tightened on all PVC pipes., Discussion: The current study suggests that commercial windlass TQs can be applied to upper and lower extremities of children aged 5 years and older at the 50%th percentile for limb circumference. In younger children, windlass TQ efficacy is variable. Further study is required to better understand the limitations of TQs in the youngest children, and to determine actual hemorrhage control efficacy., (© Association of Military Surgeons of the United States 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2019
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32. Cryoballoon Ablation for the Treatment of Atrial Fibrillation: A Meta-analysis.
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Patel N, Patel K, Shenoy A, Baker WL, Makaryus AN, and El-Sherif N
- Subjects
- Atrial Fibrillation physiopathology, Female, Humans, Male, Middle Aged, Treatment Outcome, Atrial Fibrillation surgery, Catheter Ablation methods, Cryosurgery methods
- Abstract
Background: Ablation therapy is the treatment of choice in antiarrhythmic drugrefractory atrial fibrillation (AF). It is performed by either cryoballoon ablation (CBA) or radiofrequency ablation. CBA is gaining popularity due to simplicity with similar efficacy and complication rate compared with RFA. In this meta-analysis, we compare the recurrence rate of AF and the complications from CBA versus RFA for the treatment of AF., Methods: We systematically searched PubMed for the articles that compared the outcome of interest. The primary outcome was to compare the recurrence rate of AF between CBA and RFA. We also included subgroup analysis with complications of pericardial effusion, phrenic nerve palsy and cerebral microemboli following ablation therapy., Results: A total of 24 studies with 3527 patients met our predefined inclusion criteria. Recurrence of AF after CBA or RFA was similar in both groups (RR: 0.84; 95% CI: 0.65, 1.07; I2=48%, Cochrane p=0.16). In subgroup analysis, heterogeneity was less in paroxysmal AF (I2=0%, Cochrane p=0.46) compared to mixed AF (I2=72%, Cochrane p=0.003). Procedure and fluoroscopy time was less by 26.37 and 5.94 minutes respectively in CBA compared to RFA. Complications, pericardial effusion, and silent cerebral microemboli, were not different between the two groups, however, phrenic nerve palsy was exclusively present only in CBA group., Conclusion: This study confirms that the effectiveness of CBA is similar to RFA in the treatment of AF with the added advantages of shorter procedure and fluoroscopy times., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2019
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33. Interleukin-6 inhibition of hERG underlies risk for acquired long QT in cardiac and systemic inflammation.
- Author
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Aromolaran AS, Srivastava U, Alí A, Chahine M, Lazaro D, El-Sherif N, Capecchi PL, Laghi-Pasini F, Lazzerini PE, and Boutjdir M
- Subjects
- Animals, Anti-Arrhythmia Agents therapeutic use, Arrhythmias, Cardiac drug therapy, ERG1 Potassium Channel antagonists & inhibitors, ERG1 Potassium Channel genetics, Guinea Pigs, HEK293 Cells, Humans, Inflammation drug therapy, Long QT Syndrome drug therapy, Long QT Syndrome metabolism, Membrane Potentials drug effects, Receptors, Interleukin-6 metabolism, Swine, Arrhythmias, Cardiac metabolism, ERG1 Potassium Channel metabolism, Inflammation metabolism, Interleukin-6 metabolism
- Abstract
Increased proinflammatory interleukin-6 (IL-6) levels are associated with acquired long QT-syndrome (LQTS) in patients with systemic inflammation, leading to higher risks for life-threatening polymorphic ventricular tachycardia such as Torsades de Pointes. However, the functional and molecular mechanisms of this association are not known. In most cases of acquired LQTS, the target ion channel is the human ether-á-go-go-related gene (hERG) encoding the rapid component of the delayed rectifier K current, IKr, which plays a critical role in cardiac repolarization. Here, we tested the hypothesis that IL-6 may cause QT prolongation by suppressing IKr. Electrophysiological and biochemical assays were used to assess the impact of IL-6 on the functional expression of IKr in HEK293 cells and adult guinea-pig ventricular myocytes (AGPVM). In HEK293 cells, IL-6 alone or in combination with the soluble IL-6 receptor (IL-6R), produced a significant depression of IKr peak and tail current densities. Block of IL-6R or Janus kinase (JAK) reversed the inhibitory effects of IL-6 on IKr. In AGPVM, IL-6 prolonged action potential duration (APD) which was further prolonged in the presence of IL-6R. Similar to heterologous cells, IL-6 reduced endogenous guinea pig ERG channel mRNA and protein expression. The data are first to demonstrate that IL-6 inhibition of IKr and the resulting prolongation of APD is mediated via IL-6R and JAK pathway activation and forms the basis for the observed clinical QT interval prolongation. These novel findings may guide the development of targeted anti-arrhythmic therapeutic interventions in patients with LQTS and inflammatory disorders., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2018
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34. Emerging Arrhythmic Risk of Autoimmune and Inflammatory Cardiac Channelopathies.
- Author
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Lazzerini PE, Capecchi PL, El-Sherif N, Laghi-Pasini F, and Boutjdir M
- Subjects
- Humans, Inflammation complications, Risk Factors, Arrhythmias, Cardiac etiology, Autoimmune Diseases complications, Cardiomyopathies complications, Channelopathies complications
- Published
- 2018
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35. Interruptions Experienced by Emergency Nurses: Implications for Subjective and Objective Measures of Workload.
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Forsyth KL, Hawthorne HJ, El-Sherif N, Varghese RS, Ernste VK, Koenig J, and Blocker RC
- Subjects
- Data Collection, Efficiency, Humans, Patient Safety, Emergency Nursing, Emergency Service, Hospital organization & administration, Task Performance and Analysis, Workload
- Abstract
Introduction: This study aimed to describe interruptions experienced by emergency nurses and establish convergence validity of 1 objective workload measure by linking interruption characteristics to objective and subjective measures of workload., Methods: Interruptions were captured in real time across 8- or 12-hour shifts using a previously validated Workflow Interruptions Tool (WIT). Data collected on each interruption included type, priority, and location where the interruption occurred. At mid- and end-shift, the Surgery Task Load Index (SURG-TLX) and the Rapid Cognitive Assessment Tool (RCAT) were administered to participating nurses to measure workload subjectively and objectively., Results: Thirty-eight emergency nurse shifts were observed. A total of 3,229 interruptions were recorded across 372.5 clinical hours and 38 shifts (means [M] = 85.0 interruptions per shift, standard deviation [SD] = 34.9; M = 8.7 interruptions per hour, SD = 3.36). The median duration per interruption was 13.0 seconds. A moderate positive association was identified between the number of interruptions experienced during a shift and the increased overall SURG-TLX workload reported at end-shift, r(36) = 0.323, P = 0.048. Also, a moderate positive association was identified between increased reaction times during the RCAT task and increased mental demand experienced at end of shift, r(36) = 0.460, P < 0.001., Discussion: This study observed interruptions throughout the entirety of a nursing shift and found that the majority of interruptions caused by the environment were low priority. Targeting interventions to reduce low-priority and environmental interruptions may aid in alleviating the impact of interruptions on clinical staff and patient care. Furthermore, results demonstrate that the frequency of interruptions was perceived to increase the nursing staff workload overall., (Copyright © 2017 SOCIETY. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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36. Acquired long QT syndrome and torsade de pointes.
- Author
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El-Sherif N, Turitto G, and Boutjdir M
- Subjects
- Electrocardiography, Humans, Phenotype, Long QT Syndrome etiology, Long QT Syndrome physiopathology, Torsades de Pointes etiology, Torsades de Pointes physiopathology
- Abstract
Since its initial description by Jervell and Lange-Nielsen in 1957, the congenital long QT syndrome (LQTS) has been the most investigated cardiac ion channelopathy. Although congenital LQTS continues to remain the domain of cardiologists, cardiac electrophysiologists, and specialized centers, the by far more frequent acquired drug-induced LQTS is the domain of all physicians and other members of the health care team who are required to make therapeutic decisions. This report will review the electrophysiological mechanisms of LQTS and torsade de pointes, electrocardiographic characteristics of acquired LQTS, its clinical presentation, management, and future directions in the field., (© 2018 Wiley Periodicals, Inc.)
- Published
- 2018
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37. Contact tracing with a real-time location system: A case study of increasing relative effectiveness in an emergency department.
- Author
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Hellmich TR, Clements CM, El-Sherif N, Pasupathy KS, Nestler DM, Boggust A, Ernste VK, Marisamy G, Koenig KR, and Hallbeck MS
- Subjects
- Adolescent, Child, Child, Preschool, Computer Systems, Electronic Health Records, Emergency Service, Hospital, Humans, Infant, Medical Staff, Hospital, Tertiary Care Centers, Whooping Cough transmission, Contact Tracing, Disease Outbreaks, Whooping Cough epidemiology
- Abstract
Background: Contact tracing is the systematic method of identifying individuals potentially exposed to infectious diseases. Electronic medical record (EMR) use for contact tracing is time-consuming and may miss exposed individuals. Real-time location systems (RTLSs) may improve contact identification. Therefore, the relative effectiveness of these 2 contact tracing methodologies were evaluated., Methods: During a pertussis outbreak in the United States, a retrospective case study was conducted between June 14 and August 31, 2016, to identify the contacts of confirmed pertussis cases, using EMR and RTLS data in the emergency department of a tertiary care medical center. Descriptive statistics and a paired t test (α = 0.05) were performed to compare contacts identified by EMR versus RTLS, as was correlation between pertussis patient length of stay and the number of potential contacts., Results: Nine cases of pertussis presented to the emergency department during the identified time period. RTLS doubled the potential exposure list (P < .01). Length of stay had significant positive correlation with contacts identified by RTLS (ρ = 0.79; P = .01) but not with EMR (ρ = 0.43; P = .25)., Conclusions: RTLS doubled the potential pertussis exposures beyond EMR-based contact identification. Thus, RTLS may be a valuable addition to the practice of contact tracing and infectious disease monitoring., (Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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38. Sudden Cardiac Death in Ischemic Heart Disease: Pathophysiology and Risk Stratification.
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El-Sherif N, Boutjdir M, and Turitto G
- Subjects
- Arrhythmias, Cardiac, Humans, Risk Factors, United States epidemiology, Death, Sudden, Cardiac, Myocardial Ischemia
- Abstract
Sudden cardiac death (SCD) accounts for approximately 360,000 deaths annually in the United States. Ischemic heart disease is the major cause of death in the general adult population. SCD can be due to arrhythmic or nonarrhythmic cardiac causes. Arrhythmic SCD may be caused by ventricular tachyarrhythmia or pulseless electrical activity/asystole. This article reviews the most recent pathophysiology and risk stratification strategies for SCD, emphasizing electrophysiologic surrogates of conduction disorder, dispersion of repolarization, and autonomic imbalance. Factors that modify arrhythmic death are addressed., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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39. Physician, Interrupted: Workflow Interruptions and Patient Care in the Emergency Department.
- Author
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Blocker RC, Heaton HA, Forsyth KL, Hawthorne HJ, El-Sherif N, Bellolio MF, Nestler DM, Hellmich TR, Pasupathy KS, and Hallbeck MS
- Subjects
- Chi-Square Distribution, Emergency Service, Hospital organization & administration, Humans, Midwestern United States, Patient Safety standards, Prospective Studies, Task Performance and Analysis, Interpersonal Relations, Patient Care standards, Physicians psychology, Workflow
- Abstract
Background: It is unclear how workflow interruptions impact emergency physicians at the point of care., Objectives: Our study aimed to evaluate interruption characteristics experienced by academic emergency physicians., Methods: This prospective, observational study collected interruptions during attending physician shifts. An interruption is defined as any break in performance of a human activity that briefly requires attention. One observer captured interruptions using a validated tablet PC-based tool that time stamped and categorized the data. Data collected included: 1) type, 2) priority of interruption to original task, and 3) physical location of the interruption. A Kruskal-Wallis H test compared interruption priority and duration. A chi-squared analysis examined the priority of interruptions in and outside of the patient rooms., Results: A total of 2355 interruptions were identified across 210 clinical hours and 28 shifts (means = 84.1 interruptions per shift, standard deviation = 14.5; means = 11.21 interruptions per hour, standard deviation = 4.45). Physicians experienced face-to-face physician interruptions most frequently (26.0%), followed by face-to-face nurse communication (21.7%), and environment (20.8%). There was a statistically significant difference in interruption duration based on the interruption priority, χ
2 (2) = 643.98, p < 0.001, where durations increased as priority increased. Whereas medium/normal interruptions accounted for 53.6% of the total interruptions, 53% of the interruptions that occurred in the patient room (n = 162/308) were considered low priority (χ2 [2, n = 2355] = 78.43, p < 0.001)., Conclusions: Our study examined interruptions over entire provider shifts and identified patient rooms as high risk for low-priority interruptions. Targeting provider-centered interventions to patient rooms may aid in mitigating the impacts of interruptions on patient safety and enhancing clinical care., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2017
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- View/download PDF
40. Congenital Long QT syndrome and torsade de pointes.
- Author
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El-Sherif N, Turitto G, and Boutjdir M
- Subjects
- Adrenergic beta-Antagonists therapeutic use, Humans, Long QT Syndrome therapy, Electrocardiography methods, Long QT Syndrome diagnosis, Long QT Syndrome physiopathology, Torsades de Pointes
- Abstract
Since its initial description by Jervell and Lange-Nielsen in 1957, the congenital long QT syndrome (LQTS) has been the most investigated cardiac ion channelopathy. A prolonged QT interval in the surface electrocardiogram is the sine qua non of the LQTS and is a surrogate measure of the ventricular action potential duration (APD). Congenital as well as acquired alterations in certain cardiac ion channels can affect their currents in such a way as to increase the APD and hence the QT interval. The inhomogeneous lengthening of the APD across the ventricular wall results in dispersion of APD. This together with the tendency of prolonged APD to be associated with oscillations at the plateau level, termed early afterdepolarizations (EADs), provides the substrate of ventricular tachyarrhythmia associated with LQTS, usually referred to as torsade de pointes (TdP) VT. This review will discuss the genetic, molecular, and phenotype characteristics of congenital LQTS as well as current management strategies and future directions in the field., (© 2017 Wiley Periodicals, Inc.)
- Published
- 2017
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- View/download PDF
41. Systemic inflammation as a novel QT-prolonging risk factor in patients with torsades de pointes.
- Author
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Lazzerini PE, Laghi-Pasini F, Bertolozzi I, Morozzi G, Lorenzini S, Simpatico A, Selvi E, Bacarelli MR, Finizola F, Vanni F, Lazaro D, Aromolaran A, El Sherif N, Boutjdir M, and Capecchi PL
- Subjects
- Aged, Aged, 80 and over, Biomarkers blood, C-Reactive Protein analysis, Case-Control Studies, Electrocardiography, Female, Humans, Inflammation blood, Inflammation diagnosis, Interleukin-1 blood, Male, Middle Aged, Predictive Value of Tests, Prospective Studies, Risk Factors, Torsades de Pointes blood, Torsades de Pointes diagnosis, Torsades de Pointes physiopathology, Tumor Necrosis Factor-alpha blood, Up-Regulation, Inflammation complications, Inflammation Mediators blood, Interleukin-6 blood, Torsades de Pointes etiology
- Abstract
Objective: Increasing evidence indicates systemic inflammation as a new potential cause of acquired long QT syndrome (LQTS), via cytokine-mediated changes in cardiomyocyte ion channels. Torsade de pointes (TdP) is a life-threatening polymorphic ventricular tachycardia occurring in patients with LQTS, usually when multiple QT-prolonging factors are simultaneously present. Since classical risk factors cannot fully explain TdP events in a number of patients, we hypothesised that systemic inflammation may represent a currently overlooked risk factor contributing to TdP development in the general population., Methods: Forty consecutive patients who experienced TdP (TdP cohort) were consecutively enrolled and circulating levels of C-reactive protein (CRP) and proinflammatory cytokines (interleukin-6 (IL-6), tumour necrosis factor alpha (TNFα), interleukin-1 (IL-1)) were compared with patients with active rheumatoid arthritis (RA), comorbidity or healthy controls. An additional 46 patients with different inflammatory conditions (acute infections, n=31; immune-mediated diseases, n=12; others, n=3) and elevated CRP (inflammatory cohort) were prospectively enrolled, and corrected QT (QTc) and cytokine levels were measured during active disease and after a CRP decrease of >75% subsequent to therapy., Results: In the TdP cohort, 80% of patients showed elevated CRP levels (median: ~3 mg/dL), with a definite inflammatory disease identifiable in 18/40 cases (acute infections, n=12; immune-mediated diseases, n=5; others, n=1). In these subjects, IL-6, but not TNFα and IL-1, was ~15-20 times higher than in controls, and comparable to RA patients. In the inflammatory cohort, where QTc prolongation was common (mean values: 456.6±30.9 ms), CRP reduction was associated with IL-6 level decrease and significant QTc shortening (-22.3 ms)., Conclusion: The data are first to show that systemic inflammation via elevated IL-6 levels may represent a novel QT-prolonging risk factor contributing to TdP occurrence in the presence of other classical risk factors. If confirmed, this could open new avenues in antiarrhythmic therapy., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)
- Published
- 2017
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42. 2017 ISHNE-HRS expert consensus statement on ambulatory ECG and external cardiac monitoring/telemetry.
- Author
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Steinberg JS, Varma N, Cygankiewicz I, Aziz P, Balsam P, Baranchuk A, Cantillon DJ, Dilaveris P, Dubner SJ, El-Sherif N, Krol J, Kurpesa M, La Rovere MT, Lobodzinski SS, Locati ET, Mittal S, Olshansky B, Piotrowicz E, Saxon L, Stone PH, Tereshchenko L, Turitto G, Wimmer NJ, Verrier RL, Zareba W, and Piotrowicz R
- Abstract
Ambulatory ECG (AECG) is very commonly employed in a variety of clinical contexts to detect cardiac arrhythmias and/or arrhythmia patterns which are not readily obtained from the standard ECG. Accurate and timely characterization of arrhythmias is crucial to direct therapies that can have an important impact on diagnosis, prognosis or patient symptom status. The rhythm information derived from the large variety of AECG recording systems can often lead to appropriate and patient-specific medical and interventional management. The details in this document provide background and framework from which to apply AECG techniques in clinical practice, as well as clinical research., (Copyright © 2017 International Society for Holter and Noninvasive Electrocardiology, Heart Rhythm Society, and Wiley Periodicals, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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43. Obstructive sleep apnea and arrhythmia: A systemic review.
- Author
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Patel N, Donahue C, Shenoy A, Patel A, and El-Sherif N
- Subjects
- Arrhythmias, Cardiac diagnosis, Arrhythmias, Cardiac therapy, Atrial Fibrillation diagnosis, Atrial Fibrillation epidemiology, Atrial Fibrillation therapy, Comorbidity, Continuous Positive Airway Pressure methods, Evidence-Based Medicine, Female, Humans, Male, Prognosis, Risk Assessment, Severity of Illness Index, Sick Sinus Syndrome diagnosis, Sick Sinus Syndrome epidemiology, Sick Sinus Syndrome therapy, Sleep Apnea, Obstructive diagnosis, Sleep Apnea, Obstructive therapy, Survival Analysis, Arrhythmias, Cardiac epidemiology, Cause of Death, Death, Sudden, Cardiac epidemiology, Sleep Apnea, Obstructive epidemiology
- Abstract
There is a growing consensus in the scientific community that suggests a strong association between obstructive sleep apnea (OSA) and cardiovascular (CVD) conditions and events, including coronary artery disease, hypertension, arrhythmia, heart failure, and sudden cardiac death. We reviewed evidence on the relationship between OSA and arrhythmia. Our conclusion, based on our review of the literature, is that the evidence supports a strong link between OSA and cardiovascular mortality, which warrants treating OSA. Continuous positive airway pressure (CPAP) appears to reduce the CVD consequences of OSA. Future research is expected to clarify the benefits and optimal application of these treatment approaches., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2017
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44. Marked QTc Prolongation and Torsades de pointes in Patients with Chronic Inflammatory Arthritis.
- Author
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Lazzerini PE, Capecchi PL, Bertolozzi I, Morozzi G, Lorenzini S, Simpatico A, Selvi E, Bacarelli MR, Acampa M, Lazaro D, El-Sherif N, Boutjdir M, and Laghi-Pasini F
- Abstract
Mounting evidence indicates that in chronic inflammatory arthritis (CIA), QTc prolongation is frequent and correlates with systemic inflammatory activation. Notably, basic studies demonstrated that inflammatory cytokines induce profound changes in potassium and calcium channels resulting in a prolonging effect on cardiomyocyte action potential duration, thus on the QT interval on the electrocardiogram. Moreover, it has been demonstrated that in rheumatoid arthritis (RA) patients, the risk of sudden cardiac death is significantly increased when compared to non-RA subjects. Conversely, to date no data are available about torsades de pointes (TdP) prevalence in CIA, and the few cases reported considered CIA only an incidental concomitant disease, not contributing factor to TdP development. We report three patients with active CIA developing marked QTc prolongation, in two cases complicated with TdP degenerating to cardiac arrest. In these patients, a blood sample was obtained within 24 h from TdP/marked QTc prolongation occurrence, and levels of IL-6, TNFα, and IL-1 were evaluated. In all three cases, IL-6 was markedly elevated, ~10 to 100 times more than reference values. Moreover, one patient also showed high circulating levels of TNFα and IL-1. In conclusion, active CIA may represent a currently overlooked QT-prolonging risk factor, potentially contributing in the presence of other "classical" risk factors to TdP occurrence. In particular, a relevant role may be played by elevated circulating IL-6 levels via direct electrophysiological effects on the heart. This fact should be carefully kept in mind, particularly when recognizable risk factors are already present and/or the addition of QT-prolonging drugs is required.
- Published
- 2016
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45. Potassium Channel Block and Novel Autoimmune-Associated Long QT Syndrome.
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Boutjdir M, Lazzerini PE, Capecchi PL, Laghi-Pasini F, and El-Sherif N
- Subjects
- Autoantibodies, Humans, Autoimmune Diseases complications, Autoimmune Diseases immunology, Autoimmune Diseases physiopathology, Long QT Syndrome etiology, Long QT Syndrome immunology, Long QT Syndrome physiopathology, Potassium Channels
- Abstract
This article reviews advances in the pathogenesis of anti-SSA/Ro antibody-induced corrected QT (QTc) prolongation in patients with autoimmune diseases; particularly connective tissue disease (CTD). Evidence shows that anti-SSA/Ro antibody-positive patients with CTD show QTc prolongation and complex ventricular arrhythmias. Molecular and functional data provide evidence that the human ether-a-go-go-related gene potassium channel conducting the rapidly activating delayed rectifier potassium current is directly inhibited by anti-SSA/Ro antibodies, resulting in action potential duration prolongation leading to QT interval lengthening. Routine electrocardiogram screening in anti-SSA/Ro antibody-positive patients and counseling for patients with other QTc prolonging risk factors is recommended., (Published by Elsevier Inc.)
- Published
- 2016
- Full Text
- View/download PDF
46. Arrhythmogenicity of Anti-Ro/SSA Antibodies in Patients With Torsades de Pointes.
- Author
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Lazzerini PE, Yue Y, Srivastava U, Fabris F, Capecchi PL, Bertolozzi I, Bacarelli MR, Morozzi G, Acampa M, Natale M, El-Sherif N, Galeazzi M, Laghi-Pasini F, and Boutjdir M
- Subjects
- Adult, Aged, Aged, 80 and over, Antibodies, Antinuclear blood, Blotting, Western, ERG1 Potassium Channel, Enzyme-Linked Immunosorbent Assay, Ether-A-Go-Go Potassium Channels metabolism, Female, Follow-Up Studies, HEK293 Cells metabolism, Humans, Male, Middle Aged, Prospective Studies, Torsades de Pointes blood, Torsades de Pointes physiopathology, Antibodies, Antinuclear immunology, Autoimmunity, Electrocardiography, Torsades de Pointes immunology
- Abstract
Background: In patients with autoimmune disease, anti-Ro/SSA antibodies (anti-Ro/SSA) are responsible for a novel autoimmune-associated long-QT syndrome by targeting the hERG potassium channel and inhibiting the related current (IKr). Because anti-Ro/SSA are also present in a significant proportion of healthy subjects and may be associated with torsades de pointes (TdP) arrhythmia, we tested the hypothesis that anti-Ro/SSA may represent a silent risk factor in patients developing TdP., Methods and Results: Twenty-five consecutive patients who experienced TdP were prospectively collected independent of ongoing therapies and concomitant diseases. Anti-Ro/SSA were detected by fluoroenzyme immunoassay, immuno-Western blotting, and line-blot immunoassay. Purified IgGs from anti-Ro/SSA-positive and anti-Ro/SSA-negative patients were tested on IKr using HEK293 cells stably expressing the hERG channel. As expected, in TdP patients, many known corrected QT interval-prolonging risk factors were simultaneously present, including hypokalemia that was the most common (52%). Anti-Ro/SSA were present in 60% of the subjects, mostly the anti-Ro/SSA-52-kD subtype detected by immuno-Western blotting only. A history of autoimmune disease was found in only 2 of anti-Ro/SSA-positive patients. Experimental data demonstrated that purified anti-Ro/SSA-positive IgGs significantly inhibited IKr and cross reacted with hERG-channel proteins. Moreover, anti-Ro/SSA-positive sera exhibited high reactivity with a peptide corresponding to the hERG-channel pore-forming region., Conclusions: Anti-Ro/SSA may represent a clinically silent novel risk factor for TdP development via an autoimmune-mediated electrophysiological interference with the hERG channel. We propose that TdP patients may benefit from specific anti-Ro/SSA testing even in the absence of autoimmune diseases as immunomodulating therapies may be effective in shortening corrected QT interval and reducing TdP recurrence risk., (© 2016 American Heart Association, Inc.)
- Published
- 2016
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47. Sepsis-Induced Takotsubo Cardiomyopathy Leading to Torsades de Pointes.
- Author
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Patel N, Shenoy A, Dous G, Kamran H, and El-Sherif N
- Abstract
Background. Takotsubo cardiomyopathy (TCM) is sudden and reversible myocardial dysfunction often attributable to physical or emotional triggers. Case Report. We describe a 51-year-old man presented to emergency department with sepsis from urinary tract infection (UTI). He was placed on cefepime for UTI and non-ST-elevation myocardial infarction protocol given elevated troponins with chest pain. Subsequently, patient was pulseless with torsades de pointes (TdP) and then converted to sinus rhythm with cardioversion. An echocardiogram revealed low ejection fraction with hypokinesis of the apical wall. Over 48 hours, the patient was extubated and stable on 3 L/min nasal cannula. He underwent a cardiac catheterization to evaluate coronary artery disease (CAD) and was found to have mild nonobstructive CAD with no further findings. Conclusion. TCM is a rare disorder presenting with symptoms similar to acute coronary syndrome. Though traditionally elicited by physical and emotional triggers leading to transient left ventricular dysfunction, our case suggests that it may also be triggered by a urinary tract infection and lead to severe QT prolongation and a malignant ventricular arrhythmia in TdP.
- Published
- 2016
- Full Text
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48. Role of pharmacotherapy in cardiac ion channelopathies.
- Author
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El-Sherif N and Boutjdir M
- Subjects
- Animals, Humans, Arrhythmias, Cardiac drug therapy, Channelopathies drug therapy
- Abstract
In the last decade, there have been considerable advances in the understanding of the pathophysiology of malignant ventricular tachyarrhythmias (VT) and sudden cardiac death (SCD). Over 80% of SCD occurs in patients with organic heart disease. However, approximately 10%-15% of SCD occurs in the presence of structurally normal heart, and the majority of these patients are young. In this group of patients, changes in genes encoding cardiac ion channels produce modifications of the function of the channel resulting in an electrophysiological substrate of VT and SCD. Collectively, these disorders are referred to as cardiac ion channelopathies. The four major syndromes in this group are: the long QT syndrome (LQTS), the Brugada syndrome (BrS), the short QT syndrome (SQTS), and the catecholaminergic polymorphic ventricular tachycardia (CPVT). Each of these syndromes includes multiple subtypes with different and sometimes complex cardiac ion channel genetic abnormalities. Many are associated with other somatic and neurological abnormalities besides the risk of VT and SCD. The current management of cardiac ion channelopathies can be summarized as follows: (1) in symptomatic patients, the implantable cardioverter defibrillator (ICD) is the only viable option; (2) in asymptomatic patients, risk stratification is necessary, followed by either the ICD, pharmacotherapy, or a combination of both. A genotype-specific approach to pharmacotherapy requires a thorough understanding of the molecular-cellular basis of arrhythmogenesis in cardiac ion channelopathies as well as the specific drug profile., (Copyright © 2015. Published by Elsevier Inc.)
- Published
- 2015
- Full Text
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49. Pathogenesis of the Novel Autoimmune-Associated Long-QT Syndrome.
- Author
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Yue Y, Castrichini M, Srivastava U, Fabris F, Shah K, Li Z, Qu Y, El-Sherif N, Zhou Z, January C, Hussain MM, Jiang XC, Sobie EA, Wahren-Herlenius M, Chahine M, Capecchi PL, Laghi-Pasini F, Lazzerini PE, and Boutjdir M
- Subjects
- Adult, Aged, Animals, Antibodies, Anti-Idiotypic immunology, Antibodies, Anti-Idiotypic pharmacology, Arrhythmias, Cardiac epidemiology, Arrhythmias, Cardiac physiopathology, Autoimmune Diseases immunology, Cells, Cultured, Disease Models, Animal, ERG1 Potassium Channel, Electrocardiography, Ether-A-Go-Go Potassium Channels drug effects, Ether-A-Go-Go Potassium Channels metabolism, Female, Guinea Pigs, HEK293 Cells, Humans, Kidney drug effects, Kidney metabolism, Long QT Syndrome immunology, Male, Middle Aged, Myocytes, Cardiac drug effects, Myocytes, Cardiac metabolism, Risk Factors, Antibodies, Anti-Idiotypic physiology, Autoimmune Diseases etiology, Autoimmune Diseases physiopathology, Long QT Syndrome etiology, Long QT Syndrome physiopathology, Ribonucleoproteins immunology
- Abstract
Background: Emerging clinical evidence demonstrates high prevalence of QTc prolongation and complex ventricular arrhythmias in patients with anti-Ro antibody (anti-Ro Ab)-positive autoimmune diseases. We tested the hypothesis that anti-Ro Abs target the HERG (human ether-a-go-go-related gene) K(+) channel, which conducts the rapidly activating delayed K(+) current, IKr, thereby causing delayed repolarization seen as QT interval prolongation on the ECG., Methods and Results: Anti-Ro Ab-positive sera, purified IgG, and affinity-purified anti-52kDa Ro Abs from patients with autoimmune diseases and QTc prolongation were tested on IKr using HEK293 cells expressing HERG channel and native cardiac myocytes. Electrophysiological and biochemical data demonstrate that anti-Ro Abs inhibit IKr to prolong action potential duration by directly binding to the HERG channel protein. The 52-kDa Ro antigen-immunized guinea pigs showed QTc prolongation on ECG after developing high titers of anti-Ro Abs, which inhibited native IKr and cross-reacted with guinea pig ERG channel., Conclusions: The data establish that anti-Ro Abs from patients with autoimmune diseases inhibit IKr by cross-reacting with the HERG channel likely at the pore region where homology between anti-52-kDa Ro antigen and HERG channel is present. The animal model of autoimmune-associated QTc prolongation is the first to provide strong evidence for a pathogenic role of anti-Ro Abs in the development of QTc prolongation. It is proposed that adult patients with anti-Ro Abs may benefit from routine ECG screening and that those with QTc prolongation should receive counseling about drugs that may increase the risk for life-threatening arrhythmias., (© 2015 American Heart Association, Inc.)
- Published
- 2015
- Full Text
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50. Left ventricular hypertrophy and arrhythmogenesis.
- Author
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Shenasa M, Shenasa H, and El-Sherif N
- Subjects
- Humans, Hypertension, Torsades de Pointes, Arrhythmias, Cardiac, Hypertrophy, Left Ventricular
- Abstract
Left ventricular hypertrophy (LVH) poses an independent risk of increased morbidity and mortality, including atrial arrhythmias, ventricular arrhythmias, and sudden cardiac death. The most common causes of LVH are hypertension and valvular heart disease. Electrocardiography and echocardiography are the first steps in the diagnosis and evaluation of therapy in patients with LVH. Cardiac MRI is the gold standard in diagnosis and assessment of response to therapy. Management of LVH should be based on etiology, evidence, and guideline adherence. Timely and optimal management of the underlying cause of LVH results in improvement (regression) of LVH and its related complications., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
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