Sinoatrial node function and the role of sinoatrial conduction in the typical atrial flutter substrate.

Background: Sinoatrial node (SAN) activation and sinoatrial conduction pathways (SACPs) have been assessed in animals but not in humans.

Objectives: We used ultrahigh-density mapping and simulated models to characterize the SAN and to investigate whether slowed SAN conduction may contribute to the atrial flutter (AFL) substrate.

Methods: Twenty-seven patients undergoing electrophysiologic procedures had right atrial mapping.

Proteomics couples electrical remodelling to inflammation in a murine model of heart failure with sinus node dysfunction.

Aims: In patients with heart failure (HF), concomitant sinus node dysfunction (SND) is an important predictor of mortality, yet its molecular underpinnings are poorly understood. Using proteomics, this study aimed to dissect the protein and phosphorylation remodelling within the sinus node in an animal model of HF with concurrent SND.

Methods And Results: We acquired deep sinus node proteomes and phosphoproteomes in mice with heart failure and SND and report extensive remodelling.

Cardiac GR Mediates the Diurnal Rhythm in Ventricular Arrhythmia Susceptibility.

Background: Ventricular arrhythmias (VAs) demonstrate a prominent day-night rhythm, commonly presenting in the morning. Transcriptional rhythms in cardiac ion channels accompany this phenomenon, but their role in the morning vulnerability to VAs and the underlying mechanisms are not understood. We investigated the recruitment of transcription factors that underpins transcriptional rhythms in ion channels and assessed whether this mechanism was pertinent to the heart's intrinsic diurnal susceptibility to VA.

Symptomatic bradyarrhythmias in the athlete-Underlying mechanisms and treatments.

Bradyarrhythmias including sinus bradycardia and atrioventricular (AV) block are frequently encountered in endurance athletes especially at night. While these are well tolerated by the young athlete, there is evidence that generally from the fifth decade of life onward, such arrhythmias can degenerate into pathological symptomatic bradycardia requiring pacemaker therapy. For many years, athletic bradycardia and AV block have been attributed to high vagal tone, but work from our group has questioned this widely held assumption and demonstrated a role for intrinsic electrophysiological remodeling of the sinus node and the AV node.

How mutual aid proliferation developed solidarity and sense of collective responsibility in the early months of COVID-19.

Although mutual aid organizing is a social movement practice long sustained by queer/trans people, immigrants, people of color, and disability communities, among other communities pushed to the margins of society, with the emergence of the COVID-19 pandemic, and subsequent government failures in addressing unmet needs, mutual aid proliferated into new (and more socially privileged) communities in the United States and across the world. Amidst this landscape of extraordinary and unique crises, our study sought to understand the benefits experienced by those engaged in mutual aid in the early months of the COVID-19 pandemic in the state of Colorado, United States. Our team conducted semistructured individual interviews with 25 individuals participating in mutual aid through groups organized on social media or through intentional communities.