Intramyocardial Inflammation after COVID-19 Vaccination: An Endomyocardial Biopsy-Proven Case Series.

Myocarditis in response to COVID-19 vaccination has been reported since early 2021. In particular, young male individuals have been identified to exhibit an increased risk of myocardial inflammation following the administration of mRNA-based vaccines. Even though the first epidemiological analyses and numerous case reports investigated potential relationships, endomyocardial biopsy (EMB)-proven cases are limited.

Right ventricular myocardial systolic and diastolic dysfunction in heart failure with normal left ventricular ejection fraction.

Objective: We hypothesized that in patients with heart failure with normal left ventricular (LV) ejection fraction (HFNEF), the same fibrotic processes that affect the subendocardial layer of the LV could also alter the subendocardial fibers of the right ventricle (RV). Consequently, these alterations and to a lesser extent chronically elevated pulmonary arterial pressures would lead to both systolic and diastolic subendocardial dysfunction of the RV (i.e.

Left atrial systolic and diastolic dysfunction in heart failure with normal left ventricular ejection fraction.

Background: The authors hypothesized that in patients with heart failure with normal left ventricular (LV) ejection fraction (HFNEF), the same fibrotic processes that affect the subendocardial layer of the left ventricle could also alter the subendocardial fibers of the left atrium. Consequently, these fibrotic alterations, together with chronically elevated LV filling pressures, would lead to both systolic and diastolic subendocardial dysfunction of the left atrium (i.e.

Plasma HER2 levels are not associated with cardiac function or hypertrophy in control subjects and heart failure patients.

A proper interaction between the endocardial-derived ligand Neuregulin-1 and the myocardial "Human Epidermal growth factor Receptor 2" (HER2) is essential for maintaining heart function. The shed extracellular domain (ECD) of HER2 circulates in blood and serves as a surrogate marker for breast cancer. Altered cardiac loading conditions are accompanied by dysregulation of the myocardial HER2 gene expression.