In this article, we explore the clinical and cellular phenomena of primary electrical diseases of the heart, that is, conditions purely related to ion channel dysfunction and not structural heart disease or reversible acquired causes. This growing classification of conditions, once considered together as "idiopathic ventricular fibrillation," continues to evolve and segregate into diseases that are phenotypically, molecularly, and genetically unique.
Aims: Sudden arrhythmic death syndrome (SADS) refers to a sudden death, which remains unexplained despite comprehensive post-mortem examination and a toxicological screen. We aimed to investigate the impact of age and sex on the overall diagnostic yield and underlying aetiology in decedents with SADS using a combined approach of familial evaluation (FE) and molecular autopsy (MA).
Methods And Results: Consecutive referrals to a single centre for FE only, MA only or both, following a SADS death were included.
Department of Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota, USA; Department of Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), Mayo Clinic, Rochester, Minnesota, USA; Department of Cardiovascular Medicine (Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic), Mayo Clinic, Rochester, Minnesota, USA. Electronic address:
Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare, potentially life-threatening genetic heart disease. Nonselective beta-blockers (BBs) are highly effective in reducing CPVT-triggered arrhythmic events. However, some patients suffer from unacceptable BB side effects and might require strategies without a BB.
Key Laboratory of Medical Electrophysiology of the Ministry of Education, Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000, China.
Unlabelled: Abnormal regional variations in electrical and calcium homeostasis properties have been implicated in catecholaminergic polymorphic ventricular tachycardias (CPVT) attributable to abnormal RyR2-mediated store Ca release, but their underlying mechanism have not been well explored in intact hearts.
Methods: We performed in vivo and ex vivo studies including high throughput mapping of Ca transients (CaT) and transmembrane voltage (V) in murine wild-type (WT) and heterozygous -R2474S/+ hearts, before and during isoprenaline (ISO) challenge.
Results: ISO-challenged -R2474S/+ showed increased incidence of arrhythmia accompanied by abnormal Ca transients compared to WT.
Ventricular arrhythmias (VA) are a major cause of morbidity and mortality in patients with coronary artery disease (CAD). Current guidelines recommend revascularization of significant CAD to improve survival in patients with ventricular fibrillation (VF), polymorphic ventricular tachycardia (VT), or those who are post-cardiac arrest. However, revascularization is not recommended for CAD patients with suspected scar-mediated monomorphic VT.
Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic arrhythmic syndrome caused by mutations in the calcium (Ca) release channel ryanodine receptor (RyR2) and its accessory proteins. These mutations make the channel leaky, resulting in Ca-dependent arrhythmias. Besides arrhythmias, CPVT hearts typically lack structural cardiac remodeling, a characteristic often observed in other cardiac conditions (heart failure, prediabetes) also marked by RyR2 leak.
