Dual calcium-voltage optical mapping of regional voltage and calcium signals in intact murine -R2474S hearts.

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.

Brain-to-heart cholinergic synapse-calcium signaling mediates ischemic stroke-induced atrial fibrillation.

Stroke-related cardiovascular diseases have attracted considerable attention, with atrial fibrillation (AF) being among the most frequent complications. Despite increasing clinical evidence, experimental models of stroke-induced AF are still lacking, hindering mechanistic discoveries and the development of adequate therapeutics targeting this stroke-heart syndrome (SHS). This study aims to create a rat model of ischemic stroke-induced AF (ISIAF) and to explore the efficacy and mechanism of Wenxin Keli (WK), an antiarrhythmic Chinese medicine.

ECG Changes Post-pericardiocentesis for Cardiac Tamponade Secondary to Non-small Cell Carcinoma of the Lung.

Electrical alternans on electrocardiograph (ECG) is an uncommon but nearly pathognomonic sign of cardiac tamponade. Here, we present a male quadragenarian who came to the emergency department complaining of low back and right upper abdominal pain. Work-up revealed a large pericardial effusion associated with electrical alternans on ECG and clinical findings of cardiac tamponade.

Disease severity, arrhythmogenesis, and fibrosis are related to longer action potentials in tetralogy of Fallot.

Background: Arrhythmias may originate from surgically unaffected right ventricular (RV) regions in patients with tetralogy of Fallot (TOF). We aimed to investigate action potential (AP) remodelling and arrhythmia susceptibility in RV myocardium of patients with repaired and with unrepaired TOF, identify possible correlations with clinical phenotype and myocardial fibrosis, and compare findings with data from patients with atrial septal defect (ASD), a less severe congenital heart disease.

Methods: Intracellular AP were recorded ex vivo in RV outflow tract samples from 22 TOF and three ASD patients.

Tuberculous Pericarditis Presenting as Cardiac Tamponade: Role of Echocardiography.

Tuberculous pericarditis, a rare but potentially lethal manifestation of tuberculosis, poses diagnostic and therapeutic challenges in clinical practice. Its nonspecific clinical presentation often mimics other conditions, leading to delayed or missed diagnoses. We report a 25-year-old male with no past medical history, who presented with nonspecific symptoms such as fatigue, weight loss, body aches, and dyspnea.

A detailed mathematical model of the human atrial cardiomyocyte: integration of electrophysiology and cardiomechanics.

Mechano-electric regulations (MER) play an important role in the maintenance of cardiac performance. Mechano-calcium and mechano-electric feedback (MCF and MEF) pathways adjust the cardiomyocyte contractile force according to mechanical perturbations and affects electro-mechanical coupling. MER integrates all these regulations in one unit resulting in a complex phenomenon.