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) and arrhythmia inducibility. Computer simulations (MATLAB) were performed to investigate I 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 APD:179.67 ± 2.47 ms vs 153.5 ± 7.86 ms, p = .0357). When hypokalemia was introduced, the APD 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 I 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.
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http://dx.doi.org/10.1016/j.bbrc.2023.02.060 | DOI Listing |
Cureus
December 2024
Department of Pediatrics/Division of Hospital Medicine, Children's National Hospital, Washington, DC, USA.
Circ Cardiovasc Interv
December 2024
Department of Pediatrics, Pediatric Cardiology, Stanford University, Palo Alto, CA. (J.K.Y., L.W., A.C.T., H.C., A.W.R., L.F.P., S.R.C., A.M.D., D.B.M.).
Background: Varying rates of nonsustained ventricular tachycardia (NSVT) have been reported early after transcatheter pulmonary valve replacement (TPVR) with the Harmony valve, but data regarding rhythm outcomes beyond hospital discharge are limited. This study aims to characterize ventricular arrhythmias after Harmony TPVR from implant through mid-term follow-up.
Methods: Ventricular arrhythmia data from postimplant telemetry and follow-up extended rhythm monitoring (ERM) were analyzed after Harmony TPVR.
J Med Case Rep
December 2024
Department of Cardiology and Vascular Medicine, Faculty of Medicine, Universitas Padjadjaran, Hasan Sadikin General Hospital, Bandung, Indonesia.
Background: This case highlights the management of concomitant acute myocarditis and congenital long QT syndrome with electrical storm and incessant Torsade de Pointes.
Case Presentation: An 18 years-old Southeast Asian para 1 abortus 0 (P1A0) postpartum patient with cesarean section owing to severe preeclampsia, acute lymphocytic myocarditis, and prolonged QT interval owing to long QT syndrome. She has incessant Torsade de Pointes treated with beta-blocker, lidocaine, overdrive pacing with a temporary transvenous pacemaker, left cardiac sympathetic denervation per video-assisted thoracoscopic surgery, and implantable cardioverter-defibrillator implantation.
J Mol Cell Cardiol Plus
December 2024
School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK.
The growing use of nitazene synthetic opioids heralds a new phase of the opioid crisis. However, limited information exists on the toxic effects of these drugs, aside from a propensity for respiratory depression. With restricted research availability of nitazenes, we used machine-learning-based tools to evaluate five nitazene compounds' interaction potential with the hERG potassium channel, a key drug antitarget in the heart.
View Article and Find Full Text PDFStem Cell Res Ther
December 2024
Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.
Introduction: A healthy young woman, age 26 without prior cardiac complications, experienced an out-of-hospital cardiac arrest caused by ventricular fibrillation (VF), which coincided with a fever. Comprehensive diagnostics including echo, CMR, exercise testing, and genetic sequencing, did not identify any potential cause. This led to the diagnosis of idiopathic VF and installment of an implantable cardioverter defibrillator, which six months later appropriately intervened another VF episode under conditions comparable to the first event.
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