Sex Hormone Profiles in Patients With Torsades de Pointes Ventricular Tachycardia: A Clinical-Electrophysiological Translational Study.

Background: Female sex is a well-recognized risk factor for long QT syndrome and torsades de pointes (TdP), likely reflecting the influence of sex hormones on ventricular repolarization. Overall, estradiol prolongs, whereas progesterone and testosterone shorten, heart rate-corrected QT interval. However, no studies have comprehensively evaluated sex hormone levels in male and female long QT syndrome patients developing TdP, nor their implications in terms of clinical outcomes and electrophysiological changes.

Novel therapeutic cav1.3-C-terminus normalizes L-type calcium current and ejection fraction in ischemia-induced murine heart failure.

Introduction: Heart failure (HF) affects approximately 6.7 million Americans and rising. Despite multi-modality therapy, patient outcomes remain suboptimal.

Calcium handling abnormalities increase arrhythmia susceptibility in DMSXL myotonic dystrophy type 1 mice.

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.

Electrophysiological basis of cardiac arrhythmia in a mouse model of myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is a multisystemic genetic disorder caused by the increased number of CTG repeats in 3' UTR of 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.

Anti-Ro/SSA Antibodies Blocking Calcium Channels as a Potentially Reversible Cause of Atrioventricular Block in Adults.

Background: In ∼50% of severe atrioventricular blocks (AVBs) occurring in adults <50 years, the underlying etiology remains unknown. Preliminary evidence from case reports suggests that autoimmunity, specifically the presence of circulating anti-Ro/SSA antibodies in the patient (acquired form), in the patient's mother (late-progressive congenital form), or in both (mixed form), could be involved in a fraction of idiopathic AVBs in adults by possibly targeting the L-type calcium channel (Ca1.2) and inhibiting the related current (I).

Contribution of cytokine-mediated prolongation of QTc interval to the multi-hit theory of Torsade de Pointes.

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.

-related epilepsy of infancy with migrating focal seizures: report of a variant with apparent gain- and loss-of-function effects.

SCN2A encodes a voltage-gated sodium channel (Na1.2) expressed throughout the central nervous system in predominantly excitatory neurons. Pathogenic variants in are associated with epilepsy and neurodevelopmental disorders.

Arrhythmogenic mechanisms of interleukin-6 combination with hydroxychloroquine and azithromycin in inflammatory diseases.

Inflammatory diseases including COVID-19 are associated with a cytokine storm characterized by high interleukin-6 (IL-6) titers. In particular, while recent studies examined COVID-19 associated arrhythmic risks from cardiac injury and/or from pharmacotherapy such as the combination of azithromycin (AZM) and hydroxychloroquine (HCQ), the role of IL-6 per se in increasing the arrhythmic risk remains poorly understood. The objective is to elucidate the electrophysiological basis of inflammation-associated arrhythmic risk in the presence of AZM and HCQ.