Injectable conductive hydrogel restores conduction through ablated myocardium.

Introduction: Therapies for substrate-related arrhythmias include ablation or drugs targeted at altering conductive properties or disruption of slow zones in heterogeneous myocardium. Conductive compounds such as carbon nanotubes may provide a novel personalizable therapy for arrhythmia treatment by allowing tissue homogenization.

Methods: A nanocellulose carbon nanotube-conductive hydrogel was developed to have conduction properties similar to normal myocardium.

Reversible cardiac dysfunction in severe COVID-19 infection, mechanisms and case report.

A previously healthy 49-year-old male patient presented with COVID-19 infection and required mechanical ventilation and extracorporeal membrane oxygenation due to severe hypoxemia. Echocardiography showed cardiac dysfunction with an apical sparing strain pattern, which rapidly normalized within a week. Apical sparing myocardial strain in patients with COVID-19 infection may suggest reverse-type stress cardiomyopathy.

Three-Dimensional Printed Biopatches With Conductive Ink Facilitate Cardiac Conduction When Applied to Disrupted Myocardium.

Background: Reentrant ventricular arrhythmias are a major cause of sudden death in patients with structural heart disease. Current treatments focus on electrically homogenizing regions of scar contributing to ventricular arrhythmia with ablation or altering conductive properties using antiarrhythmic drugs. The high conductivity of carbon nanotubes may allow restoration of conduction in regions where impaired electrical conduction results in functional abnormalities.

Management of ventricular arrhythmias in patients with ventricular assist devices.

Purpose Of Review: To summarize the available evidence concerning the occurrence and treatment of ventricular arrhythmias in patients supported with long-term ventricular assist devices (VADs).

Recent Findings: Approximately one-third of left ventricular assist device-supported patients experience significant ventricular arrhythmias, with higher rates in certain patient subsets. Ventricular arrhythmias are associated with both increased mortality and morbidity in VAD-supported patients.

Free vascularized fibular grafting preserves athletic activity level in patients with osteonecrosis.

Athletic patients with osteonecrosis of the femoral head have few desirable therapeutic options that preserve athletic ability. Because these patients are usually young and healthy, any procedure that avoids total hip arthroplasty would be most desirable. This study prospectively evaluated 15 patients (19 hips) who presented with an average age of 28.

Transcriptomic biomarkers of cardiovascular disease.

Transcriptomics is the study of how our genes are regulated and expressed in different biological settings. Technical advances now enable quantitative assessment of all expressed genes (ie, the entire "transcriptome") in a given tissue at a given time. These approaches provide a powerful tool for understanding complex biological systems and for developing novel biomarkers.

Cardiac fibroblast paracrine factors alter impulse conduction and ion channel expression of neonatal rat cardiomyocytes.

Aims: The pathological proliferation of cardiac fibroblasts (CFs) in response to heart injury results in fibrosis, which correlates with arrhythmia generation and heart failure. Here we systematically examined the effect of fibroblast-derived paracrine factors on electrical propagation in cardiomyocytes.

Methods And Results: Neonatal rat cardiac monolayers were exposed for 24 h to media conditioned by CFs.

Structural coupling of cardiomyocytes and noncardiomyocytes: quantitative comparisons using a novel micropatterned cell pair assay.

Well-controlled studies of the structural and functional interactions between cardiomyocytes and other cells are essential for understanding heart pathophysiology and for the further development of safe and efficient cell therapies. We established a novel in vitro assay composed of a large number of individual micropatterned cell pairs with reproducible shape, size, and region of cell-cell contact. This assay was applied to quantify and compare the frequency of expression and distribution of electrical (connexin43) and mechanical (N-cadherin) coupling proteins in 5,000 cell pairs made of cardiomyocytes (CMs), cardiac fibroblasts (CFs), skeletal myoblasts (SKMs), and mesenchymal stem cells (MSCs).

Angiogenesis therapies for cardiovascular disease.

Purpose Of Review: The purpose was to summarize the findings of the proangiogenic clinical trials using protein and gene therapy, with analysis of the problems and an interpretation of the results.

Recent Findings: Recent findings include several new large clinical trials, using both gene and protein therapies. There has been development of new basic science concepts, especially with regard to endothelial activation and stabilization of newly formed microvessels.

Engineering skeletal myoblasts: roles of three-dimensional culture and electrical stimulation.

Immature skeletal muscle cells, or myoblasts, have been used in cellular cardiomyoplasty in attempts to regenerate cardiac muscle tissue by injection of cells into damaged myocardium. In some studies, muscle tissue within myoblast implant sites may be morphologically similar to cardiac muscle. We hypothesized that identifiable aspects of the cardiac milieu may contribute to growth and development of implanted myoblasts in vivo.