Small Heart Size and Premature Death in 366,484 Individuals With Normal Ejection Fraction.

Background: In patients with preserved left ventricular ejection fraction (LVEF), small ventricular size has been associated with reduced functional capacity, but its impact on clinical outcomes is unclear.

Objectives: The goal of this study was to determine the relationship between small heart size and premature mortality within a large multicenter adult patient cohort with transthoracic echocardiographic examinations.

Methods: We divided 366,484 individuals with LVEF ≥50% (including a subset of 279,442 individuals with high-normal LVEF ≥60%) by sex and increasing quartiles for LV end-diastolic volume (LVEDV), LVEDV indexed to body surface area (LVEDVi), and LV end-diastolic diameter to assess associations with 5-year mortality through linkage with the National Death Index.

Sex-Specific HLA Alleles Contribute to the Modulation of COVID-19 Severity.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, responsible for Coronavirus Disease 2019 (COVID-19), exhibits a spectrum of clinical manifestations, ranging from asymptomatic to severe pulmonary dysfunction or death. The variability in COVID-19 severity has largely been attributed to the host's genetic characteristics, suggesting a polygenic genetic architecture, without significant strong evidence of sex-related genetic differences. In this Italian retrospective case-control study, we investigated the association between COVID-19 severity (severe vs.

Genetics, Fitness, and Left Ventricular Remodelling: The Current State of Play.

Cardiorespiratory fitness (CRF) exists on a spectrum and is driven by a constellation of factors, including genetic and environmental differences. This results in wide interindividual variation in baseline CRF and the ability to improve CRF with regular endurance exercise training. As opposed to monogenic conditions, CRF is described as a complex genetic trait as it is believed to be influenced by multiple common genetic variants in addition to exogenous factors.

Ventricular arrhythmias in association with athletic cardiac remodelling.

Athletes are predisposed to atrial arrhythmias but the association between intense endurance exercise training, ventricular arrhythmias (VAs), and sudden cardiac death is less well established. Thus, it is unclear whether the 'athlete's heart' promotes specific arrhythmias or whether it represents a more general pro-arrhythmogenic phenotype. Whilst direct causality has not been established, it appears possible that repeated exposure to high-intensity endurance exercise in some athletes contributes to formation of pro-arrhythmic cardiac phenotypes that underlie VAs.