Desmoplakin Cardiomyopathy: Role of Inflammation and Potential Role of Disease-Modifying Therapies.

Purpose Of Review: To summarize the available data on the use of immunosuppression therapies for the management of hot phases of disease and recurrent myocarditis in patients with desmoplakin cardiomyopathy (DSP-CMP).

Recent Findings: Occurrence of myocarditis episodes has been associated with worsening of outcomes in DSP-CMP. Multiple case reports and small case series have described potential benefit in using anti-inflammatory and immunosuppressive medications for the treatment of those episodes.

Matrix Architecture and Mechanics Regulate Myofibril Organization, Costamere Assembly, and Contractility in Engineered Myocardial Microtissues.

The mechanical function of the myocardium is defined by cardiomyocyte contractility and the biomechanics of the extracellular matrix (ECM). Understanding this relationship remains an important unmet challenge due to limitations in existing approaches for engineering myocardial tissue. Here, they established arrays of cardiac microtissues with tunable mechanics and architecture by integrating ECM-mimetic synthetic, fiber matrices, and induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), enabling real-time contractility readouts, in-depth structural assessment, and tissue-specific computational modeling.

The Clinical Trajectory of NYHA Functional Class I Patients With Obstructive Hypertrophic Cardiomyopathy.

Background: An improved understanding of the natural history in NYHA functional class I patients with obstructive hypertrophic cardiomyopathy (oHCM) is needed.

Objectives: Using a multicenter registry (SHaRe [Sarcomeric Human Cardiomyopathy Registry]), this study described the natural history in patients with oHCM who were classified as NYHA functional class I at the initial visit compared with patients classified as NYHA functional class II and reported baseline characteristics associated with incident clinical events.

Methods: Incident events assessed included a composite of NYHA functional class III to IV symptoms, left ventricular ejection fraction <50%, atrial fibrillation, stroke, ventricular arrhythmias, septal reduction therapy, ventricular assist device or transplantation, or death.

FICD deficiency protects mice from hypertrophy-induced heart failure via BiP-mediated activation of the UPR and ER-phagy.

Cardiomyocytes require the HSP70 chaperone BiP to maintain proteostasis in the endoplasmic reticulum (ER) following cardiac stress. The adenylyl transferase (AMPylase) FICD is increasingly recognized to regulate BiP activity through the post-translational addition of an adenosine monophosphate moiety to BiP surface residues. However, the physiological impact of FICD-mediated BiP regulation in the context of cardiovascular health is unknown.

In Vitro Assessment of Cardiac Fibroblast Activation at Physiologic Stiffness.

Cardiac fibroblasts (CF) are an essential cell type in cardiac physiology, playing diverse roles in maintaining structural integrity, extracellular matrix (ECM) synthesis, and tissue repair. Under normal conditions, these cells reside in the interstitium in a quiescent state poised to sense and respond to injury by synthesizing and secreting collagen, vimentin, hyaluronan, and other ECM components. In response to mechanical and chemical stimuli, these "resident" fibroblasts can undergo a transformation through a continuum of activation states into what is commonly known as a "myofibroblast," in a process critical for injury response.

A Case of Reverse McConnell's Sign Associated With Acute Respiratory Distress Syndrome and Septic Shock.

We present a case of reverse McConnell's sign, a rare echocardiographic finding of right ventricular apical hypokinesis and basal hyperkinesis, in a patient with acute respiratory distress syndrome and septic shock. Although multiple etiologies were hypothesized, providers attributed this cardiomyopathy to increased right heart afterload from hypoxic pulmonary vasoconstriction. Cardiac function normalized as the patient's respiratory failure and sepsis resolved.

Integrating mechanical cues with engineered platforms to explore cardiopulmonary development and disease.

Mechanical forces provide critical biological signals to cells during healthy and aberrant organ development as well as during disease processes in adults. Within the cardiopulmonary system, mechanical forces, such as shear, compressive, and tensile forces, act across various length scales, and dysregulated forces are often a leading cause of disease initiation and progression such as in bronchopulmonary dysplasia and cardiomyopathies. Engineered models have supported studies of mechanical forces in a number of tissue and disease-specific contexts, thus enabling new mechanistic insights into cardiopulmonary development and disease.

Matrix architecture and mechanics regulate myofibril organization, costamere assembly, and contractility of engineered myocardial microtissues.

The mechanical function of the myocardium is defined by cardiomyocyte contractility and the biomechanics of the extracellular matrix (ECM). Understanding this relationship remains an important unmet challenge due to limitations in existing approaches for engineering myocardial tissue. Here, we established arrays of cardiac microtissues with tunable mechanics and architecture by integrating ECM-mimetic synthetic, fiber matrices and induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), enabling real-time contractility readouts, in-depth structural assessment, and tissue-specific computational modeling.

Spatial Single Cell Analysis of Proteins in 2D Human Gastruloids Using Iterative Immunofluorescence.

During development, cell signaling instructs tissue patterning, the process by which initially identical cells give rise to spatially organized structures consisting of different cell types. How multiple signals combinatorially instruct fate in space and time remains poorly understood. Simultaneous measurement of signaling activity through multiple signaling pathways and of the cell fates they control is critical to addressing this problem.

An Unbiased Screen Identified the Hsp70-BAG3 Complex as a Regulator of Myosin-Binding Protein C3.

Variants in the gene myosin-binding protein C3 () account for approximately 50% of familial hypertrophic cardiomyopathy (HCM), leading to reduced levels of myosin-binding protein C3 (MyBP-C), the protein product made by gene . Elucidation of the pathways that regulate MyBP-C protein homeostasis could uncover new therapeutic strategies. Toward this goal, we screened a library of 2,426 bioactive compounds and identified JG98, an allosteric modulator of heat shock protein 70 that inhibits interaction with Bcl-2-associated athanogene (BAG) domain co-chaperones.

Value of genotyping and scar-phenotyping for VT ablation procedures in patients with nonischemic left ventricular cardiomyopathies.

Introduction: Variants of cardiomyopathy genes in patients with nonischemic cardiomyopathy (NICM) generate various phenotypes of cardiac scar and delayed enhancement cardiac magnetic resonance (DE-CMR) imaging which may impact ventricular tachycardia (VT) management.

Methods: The objective was to compare the findings of cardiomyopathy genetic testing on DE-CMR imaging and long-term outcomes among patients with NICM undergoing VT ablation procedures. Image phenotyping and genotyping were performed in a consecutive series of patients referred for VT ablation and correlated to survival free of VT.

Left Ventricular Systolic Dysfunction in Patients Diagnosed With Hypertrophic Cardiomyopathy During Childhood: Insights From the SHaRe Registry.

Background: The development of left ventricular systolic dysfunction (LVSD) in hypertrophic cardiomyopathy (HCM) is rare but serious and associated with poor outcomes in adults. Little is known about the prevalence, predictors, and prognosis of LVSD in patients diagnosed with HCM as children.

Methods: Data from patients with HCM in the international, multicenter SHaRe (Sarcomeric Human Cardiomyopathy Registry) were analyzed.

Left and Right PVC-Induced Ventricular Dysfunction.

Background: Frequent premature ventricular complexes (PVCs) can result in a reversible form of cardiomyopathy that usually affects the left ventricle (LV).

Objectives: The objective of this study was to assess whether frequent PVCs have an impact on right ventricular (RV) function.

Methods: Serial cardiac magnetic resonance (CMR) studies were performed in a series of 47 patients before and after ablation of frequent PVCs.

Probabilistic integration of transcriptome-wide association studies and colocalization analysis identifies key molecular pathways of complex traits.

Integrative genetic association methods have shown great promise in post-GWAS (genome-wide association study) analyses, in which one of the most challenging tasks is identifying putative causal genes and uncovering molecular mechanisms of complex traits. Recent studies suggest that prevailing computational approaches, including transcriptome-wide association studies (TWASs) and colocalization analysis, are individually imperfect, but their joint usage can yield robust and powerful inference results. This paper presents INTACT, a computational framework to integrate probabilistic evidence from these distinct types of analyses and implicate putative causal genes.

Impact of SARS-Cov-2 infection in patients with hypertrophic cardiomyopathy: results of an international multicentre registry.

Aims: To describe the natural history of SARS-CoV-2 infection in patients with hypertrophic cardiomyopathy (HCM) compared with a control group and to identify predictors of adverse events.

Methods And Results: Three hundred and five patients [age 56.6 ± 16.

Translation of New and Emerging Therapies for Genetic Cardiomyopathies.

The primary etiology of a diverse range of cardiomyopathies is now understood to be genetic, creating a new paradigm for targeting treatments on the basis of the underlying molecular cause. This review provides a genetic and etiologic context for the traditional clinical classifications of cardiomyopathy, including molecular subtypes that may exhibit differential responses to existing or emerging treatments. The authors describe several emerging cardiomyopathy treatments, including gene therapy, direct targeting of myofilament function, protein quality control, metabolism, and others.

External validation of the HCM Risk-Kids model for predicting sudden cardiac death in childhood hypertrophic cardiomyopathy.

Aims: Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM). The newly developed HCM Risk-Kids model provides clinicians with individualized estimates of risk. The aim of this study was to externally validate the model in a large independent, multi-centre patient cohort.

Physiologic biomechanics enhance reproducible contractile development in a stem cell derived cardiac muscle platform.

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) allow investigations in a human cardiac model system, but disorganized mechanics and immaturity of hPSC-CMs on standard two-dimensional surfaces have been hurdles. Here, we developed a platform of micron-scale cardiac muscle bundles to control biomechanics in arrays of thousands of purified, independently contracting cardiac muscle strips on two-dimensional elastomer substrates with far greater throughput than single cell methods. By defining geometry and workload in this reductionist platform, we show that myofibrillar alignment and auxotonic contractions at physiologic workload drive maturation of contractile function, calcium handling, and electrophysiology.