Wnts are required for cardiogenesis but the role of specific Wnts in cardiac repair remains unknown. In this report, we show that a dynamic Wnt1/βcatenin injury response activates the epicardium and cardiac fibroblasts to promote cardiac repair. Acute ischaemic cardiac injury upregulates Wnt1 that is initially expressed in the epicardium and subsequently by cardiac fibroblasts in the region of ...

BACKGROUND The efficacy of transcatheter cryoablation for ventricular tachycardia (VT) remains controversial because of the limited size of the lesion produced. An increased lesion size if the cryoablation catheter profile and catheter tip length were increased was hypothesized. METHODS AND RESULTS Closed-chest transcatheter cryoablation was applied with 7F, 6-mm tip (n=11, 7F group) and 9F, ...

Recent work has demonstrated the importance of the epicardium in the development of the heart. During embryogenesis, these epithelial cells provide the progenitors for the epicardium, coronary smooth muscle, endothelium, and cardiac fibroblasts. The epicardium sends important signals to the developing myocardium. Still, analysis of these epithelial cells has lagged behind that of other cardiac ...

Atrial fibrillation (AF) is characterized by complex and irregular propagation patterns. Noninvasive electrocardiographic imaging (ECGI) has been tested during AF conditions with promising results. However, current regularization methods face important challenges in this type of unstable electrical activity scenarios. Combination intracardiac non-invasive simultaneous recordings could improve E...

BACKGROUND The role of dispersion of refractoriness and reentry for the genesis of polymorphic ventricular tachycardia (VT) has recently become emphasized. We investigated the mechanisms of polymorphic arrhythmias in a 2D preparation confining an area of prolonged refractoriness. METHODS AND RESULTS In 16 Langendorff-perfused rabbit hearts, a sheet of left ventricular epicardium was obtained ...

A case is presented of the rare condition of constrictive epicarditis, which was treated successfully by removal of the epicardium. This appears to be the first account of constrictive epicarditis following proven Coxsackie viral infection.

BACKGROUND Recently, we demonstrated the feasibility and safety of circular electroporation ablation in porcine pulmonary vein ostia, but the relationship between the magnitude of the application and lesion dimensions is still unknown. METHODS AND RESULTS An in vivo porcine study was performed on left ventricular epicardium submerged under 10 mm of blood, using devices that mimic a 20-mm-diam...

RATIONALE The basic helix-loop-helix (bHLH) transcription factors Hand1 and Hand2 are essential for embryonic development. Given their requirement for cardiogenesis, it is imperative to determine their impact on cardiovascular function. OBJECTIVE To deduce the role of Hand2 within the epicardium. METHOD AND RESULTS We engineered a Hand1 allele expressing Cre recombinase. Cardiac Hand1 expre...

A winter outbreak of ascites in cultured Japanese amberjack Seriola quinqueradiata was examined. Affected fish displayed bloody ascitic fluid in the peritoneal cavity, their hearts were covered with a white membrane, their livers were congested and their kidneys were swollen. Renal tubular epithelia displayed extensive necrosis and often contained hyaline droplets, while some glomeruli showed a...