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Naik R, Thyagaturu H, Awad M, Bischof E. The Heart Remembers: A Case of Cardiac Memory. Cureus 2023; 15:e42106. [PMID: 37602025 PMCID: PMC10436023 DOI: 10.7759/cureus.42106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2023] [Indexed: 08/22/2023] Open
Abstract
An 80-year-old male with a history of atrial fibrillation and a single-chamber ventricular pacemaker presented to the hospital for an elective colonoscopy. He experienced a transient episode of unresponsiveness with seizure-like activity before the procedure. This prompted him to get an EKG showing deep T-wave inversions (TWIs) in the precordial leads on a background of paced beats. Such findings were concerning for an acute and potentially life-threatening process such as myocardial infarction (MI) or intracranial insult. After ruling out any severe conditions, the EKG findings were attributed to cardiac memory, an underdiagnosed cause of deep TWIs in patients with a pacemaker.
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Affiliation(s)
- Riddhima Naik
- Internal Medicine, Bassett Healthcare Network, Cooperstown, USA
| | | | - Maan Awad
- Internal Medicine, West Virginia University School of Medicine, Morgantown, USA
| | - Edward Bischof
- Internal Medicine, Bassett Healthcare Network, Cooperstown, USA
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Wang X, Feng Y, Liu S, Liu J, Pan S, Wei L, Ma Y, Liu Z, Xing Y, Wang J, Cui Q, Zhang Y, Wang T, Cai C. Hydroxychloroquine Attenuates hERG Channel by Promoting the Membrane Channel Degradation: Computational Simulation and Experimental Evidence for QT-Interval Prolongation with Hydroxychloroquine Treatment. Cardiology 2023; 148:310-323. [PMID: 37231805 DOI: 10.1159/000531132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 05/11/2023] [Indexed: 05/27/2023]
Abstract
INTRODUCTION The coronavirus disease 2019 (COVID-19) pandemic has led to millions of confirmed cases and deaths worldwide and has no approved therapy. Currently, more than 700 drugs are tested in the COVID-19 clinical trials, and full evaluation of their cardiotoxicity risks is in high demand. METHODS We mainly focused on hydroxychloroquine (HCQ), one of the most concerned drugs for COVID-19 therapy, and investigated the effects and underlying mechanisms of HCQ on hERG channel via molecular docking simulations. We further applied the HEK293 cell line stably expressing hERG-wild-type channel (hERG-HEK) and HEK293 cells transiently expressing hERG-p.Y652A or hERG-p.F656A mutants to validate our predictions. Western blot analysis was used to determine the hERG channel, and the whole-cell patch clamp was utilized to record hERG current (IhERG). RESULTS HCQ reduced the mature hERG protein in a time- and concentration-dependent manner. Correspondingly, chronic and acute treatment of HCQ decreased the hERG current. Treatment with brefeldin A (BFA) and HCQ combination reduced hERG protein to a greater extent than BFA alone. Moreover, disruption of the typical hERG binding site (hERG-p.Y652A or hERG-p.F656A) rescued HCQ-mediated hERG protein and IhERG reduction. CONCLUSION HCQ can reduce the mature hERG channel expression and IhERG via enhancing channel degradation. The QT prolongation effect of HCQ is mediated by typical hERG binding sites involving residues Tyr652 and Phe656.
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Affiliation(s)
- Xiqiang Wang
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Yunfei Feng
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Senmiao Liu
- Division of Data Intelligence, Department of Computer Science, Key Laboratory of Intelligent Manufacturing Technology of Ministry of Education, College of Engineering, Shantou University, Shantou, China
| | - Jing Liu
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Shuo Pan
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Linyan Wei
- Department of General Practice, The Second Affiliated Hospital Zhejiang University School of Medicine, Hangzhou, China
| | - Yanpeng Ma
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Zhongwei Liu
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Yujie Xing
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Junkui Wang
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Qianwei Cui
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Yong Zhang
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Tingzhong Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Chuipu Cai
- Division of Data Intelligence, Department of Computer Science, Key Laboratory of Intelligent Manufacturing Technology of Ministry of Education, College of Engineering, Shantou University, Shantou, China
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Sharif S, Tang J. Potassium Derangements: A Pathophysiological Review, Diagnostic Approach, and Clinical Management. Physiology (Bethesda) 2022. [DOI: 10.5772/intechopen.103016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Potassium is an essential cation critical in fluid and electrolyte balance, acid–base regulation, and neuromuscular functions. The normal serum potassium is kept within a narrow range of 3.5–5.2 meq/L while the intracellular concentration is approximately 140–150 meq/L. The total body potassium is about 45–55 mmol/kg; thus, a 70 kg male has an estimated ~136 g and 60 kg female has ~117 g of potassium. In total, 98% of the total body potassium is intracellular. Skeletal muscle contains ~80% of body potassium stores. The ratio of intracellular to extracellular potassium concentration (Ki/Ke) maintained by Na+/K+ ATPase determines the resting membrane potential. Disturbances of potassium homeostasis lead to hypo- and hyperkalemia, which if severe, can be life-threatening. Prompt diagnosis and management of these problems are important.
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Bamgbola OF. Review of the Pathophysiologic and Clinical Aspects of Hypokalemia in Children and Young Adults: an Update. CURRENT TREATMENT OPTIONS IN PEDIATRICS 2022; 8:96-114. [PMID: 37521171 PMCID: PMC9115742 DOI: 10.1007/s40746-022-00240-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 04/18/2022] [Indexed: 11/28/2022]
Abstract
This article examines the regulatory function of the skeletal muscle, renal, and adrenergic systems in potassium homeostasis. The pathophysiologic bases of hypokalemia, systematic approach for an early diagnosis, and therapeutic strategy to avert life-threatening complications are highlighted. By promoting skeletal muscle uptake, intense physical exercise (post), severe trauma, and several toxins produce profound hypokalemia. Hypovolemia due to renal and extra-renal fluid losses and ineffective circulation activate secondary aldosteronism causing urinary potassium wasting. In addition to hypokalemic alkalosis, primary aldosteronism causes low-renin hypertension. Non-aldosterone mineralocorticoid activation leading to low-renin and low-aldosterone hypertension occurs in Liddle's syndrome and apparent mineralocorticoid excess. Although there is enzymatic inhibition of cortisol synthesis in congenital adrenal hyperplasia, precursors of aldosterone produce low-renin hypokalemic hypertension. In addition to the glucocorticoid effect, hypercortisolism activates mineralocorticoid receptors in Cushing's syndrome. Genetic mutations involving furosemide-sensitive Na+-K+-2Cl- co-transporters and thiazide-sensitive Na+-Cl- transporters result in (non-hypertensive) salt-wasting nephropathy. Proximal and distal renal tubular acidosis is associated with hypokalemia. Eating disorders causing hypokalemia include bulimia, laxative abuse, and diuretic misuse. Low urinary potassium (<15 mmol/day) and/or low urinary chloride (<20 mol/L) suggest a gastrointestinal pathology. Co-morbidity of hypokalemia with chronic pulmonary and cardiovascular diseases may increase the fatality rate.
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Affiliation(s)
- Oluwatoyin Fatai Bamgbola
- Division of Pediatric Nephrology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203 USA
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Thinda N, Ambrose JA, Bhullar A, Huang S, Asadourian M, Sadhale A, Chua RA, Wessel R. New Precordial T Wave Inversions in Hospitalized Patients. Am J Med 2022; 135:517-523. [PMID: 34813739 DOI: 10.1016/j.amjmed.2021.10.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/18/2021] [Accepted: 10/18/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND The incidence of precordial T changes has been described in athletes and in specific populations, while the etiology in a large patient population admitted to the hospital has not previously been reported. METHODS All electrocardiograms (ECGs) read by the same physician with new (compared to prior ECGs) or presumed new (no prior ECGs) precordial T wave inversions of >1 mm (0.1 mV) in multiple precordial leads were retrospectively reviewed and various ECG, patient-related, and imaging parameters assessed. A total of 226 patients and their ECGs were initially selected for analysis. Of these, 35 were eliminated leaving 191 for the final analysis. RESULTS Patients and their ECGs were divided into 5 groups based on diagnosis and incidence including Wellens syndrome, takotsubo, type 2 myocardial infarction, other (including multiple diagnoses), and unknown. Although subtle differences including number of T inversion leads, depth of T waves, QTc intervals, and other variables were present between some groups, diagnosis in individual cases required appropriate clinical, laboratory, or imaging studies. For example, although Wellens syndrome was identified in <20% of cases, a presenting history of chest discomfort with precordial T changes either on the admission or next-day ECG was highly sensitive and specific for this diagnosis. In some cases, type 2 myocardial infarction can also have a Wellens-like ECG phenotype without significant left anterior descending disease. CONCLUSIONS Precordial T wave changes in hospitalized patients have various etiologies, and in individual cases, the changes on the ECG alone cannot easily distinguish the presumptive diagnosis and additional data are required.
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Affiliation(s)
| | | | | | - Siyi Huang
- Department of Internal Medicine, University of California San Francisco, Fresno, Calif
| | - Miro Asadourian
- Department of Internal Medicine, University of California San Francisco, Fresno, Calif
| | - Ashwini Sadhale
- Department of Internal Medicine, University of California San Francisco, Fresno, Calif
| | - Rochelle Anne Chua
- Department of Internal Medicine, University of California San Francisco, Fresno, Calif
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Li J, Moten S, Rauf AA. The role of nephrologists in management of hypokalemic periodic paralysis: a case report. J Med Case Rep 2022; 16:65. [PMID: 35144692 PMCID: PMC8832865 DOI: 10.1186/s13256-022-03283-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 01/20/2022] [Indexed: 11/14/2022] Open
Abstract
Background Hypokalemic periodic paralysis is a chronic condition characterized by sporadic attacks of weakness associated with acute hypokalemia. Attacks are typically associated with specific triggers, such as prolonged rest following exercise or consumption of a high-carbohydrate meal. Most commonly, this condition is caused by an autosomal dominant calcium channel mutation, and patients typically have an established family medical history of hypokalemic periodic paralysis. Long-term complications include the development of progressive proximal myopathy. Oral potassium chloride may be considered for the treatment of an acute attack, with administration of acetazolamide or dichlorphenamide as long-term prophylaxis. Nephrologists can play an important role in the recognition and treatment of previously undiagnosed hypokalemic periodic paralysis. Case presentation We summarize the case of a 19-year-old white man who presented to the emergency department with undiagnosed attacks of hypokalemic periodic paralysis, and who reported, at follow-up, improvement in the severity and frequency of attacks with dichlorphenamide. Conclusions This case demonstrates the crucial role nephrologists can play, not only in the diagnosis of hypokalemic periodic paralysis, but also in the ongoing management of this condition. Patients should be advised to regularly follow up with their nephrology team for evaluation due to the risk of developing myopathy.
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Affiliation(s)
- Julia Li
- Midwestern University, Chicago College of Osteopathic Medicine, Downers Grove, IL, 60515, USA.
| | - Suha Moten
- Midwestern University, MABS, Downers Grove, IL, USA
| | - Anis A Rauf
- Nephrology Associates of Northern Illinois and Indiana, Hinsdale, IL, USA
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Prado NJ, Egan Beňová T, Diez ER, Knezl V, Lipták B, Ponce Zumino AZ, Llamedo-Soria M, Szeiffová Bačová B, Miatello RM, Tribulová N. Melatonin receptor activation protects against low potassium-induced ventricular fibrillation by preserving action potentials and connexin-43 topology in isolated rat hearts. J Pineal Res 2019; 67:e12605. [PMID: 31408542 DOI: 10.1111/jpi.12605] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 07/27/2019] [Accepted: 08/05/2019] [Indexed: 12/22/2022]
Abstract
Hypokalemia prolongs the QRS and QT intervals, deteriorates intercellular coupling, and increases the risk for arrhythmia. Melatonin preserves gap junctions and shortens action potential as potential antiarrhythmic mechanisms, but its properties under hypokalemia remain unknown. We hypothesized that melatonin protects against low potassium-induced arrhythmias through the activation of its receptors, resulting in action potential shortening and connexin-43 preservation. After stabilization in Krebs-Henseleit solution (4.5 mEq/L K+ ), isolated hearts from Wistar rats underwent perfusion with low-potassium (1 mEq/L) solution and melatonin (100 μmol/L), a melatonin receptor blocker (luzindole, 5 μmol/L), melatonin + luzindole or vehicle. The primary endpoint of the study was the prevention of ventricular fibrillation. Electrocardiography was used, and epicardial action potentials and heart function were measured and analyzed. The ventricular expression, dephosphorylation, and distribution of connexin-43 were examined. Melatonin reduced the incidence of low potassium-induced ventricular fibrillation from 100% to 59%, delayed the occurrence of ventricular fibrillation and induced a faster recovery of sinus rhythm during potassium restitution. Melatonin prevented QRS widening, action potential activation delay, and the prolongation of action potential duration at 50% of repolarization. Other ECG and action potential parameters, the left ventricular developed pressure, and nonsustained ventricular arrhythmias did not differ among groups. Melatonin prevented connexin-43 dephosphorylation and its abnormal topology (lateralization). Luzindole abrogated the protective effects of melatonin on electrophysiological properties and connexin-43 misdistribution. Our results indicate that melatonin receptor activation protects against low potassium-induced ventricular fibrillation, shortens action potential duration, preserves ventricular electrical activation, and prevents acute changes in connexin-43 distribution. All of these properties make melatonin a remarkable antifibrillatory agent.
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Affiliation(s)
- Natalia Jorgelina Prado
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, Mendoza, Argentina
| | - Tamara Egan Beňová
- Center of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Bratislava, Slovakia
| | - Emiliano Raúl Diez
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, Mendoza, Argentina
- Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Vladimír Knezl
- Center of Experimental Medicine, Slovak Academy of Sciences, Institute of Experimental Pharmacology and Toxicology, Bratislava, Slovakia
| | - Boris Lipták
- Center of Experimental Medicine, Slovak Academy of Sciences, Institute of Experimental Pharmacology and Toxicology, Bratislava, Slovakia
| | - Amira Zulma Ponce Zumino
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, Mendoza, Argentina
- Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Mariano Llamedo-Soria
- Department of Electronic Engineering, Universidad Tecnológica Nacional, Buenos Aires, Argentina
| | - Barbara Szeiffová Bačová
- Center of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Bratislava, Slovakia
| | - Roberto Miguel Miatello
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, Mendoza, Argentina
- Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Narcisa Tribulová
- Center of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Bratislava, Slovakia
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