Microvascular Rarefaction in the Sinoatrial Node: A Potential Mechanism for Pacemaker Dysfunction in Early HFpEF.

ABSTRACT:

Background

Microvascular rarefaction is a feature of heart failure with preserved ejection fraction (HFpEF) that may underlie associated rhythm disturbances. Angiotensin II (AngII) signaling has been implicated, but its role in sinoatrial (SA) node dysfunction remains unclear.

Objectives

The authors tested whether changes in SA node microvascular architecture contribute to pacemaker dysfunction in early HFpEF.

Methods

Mice received a 28-day subcutaneous infusion of a sub-pressor dose of AngII. Electrocardiography, echocardiography, confocal imaging, spatial RNA detection, and optical mapping were used to assess SA node structure and function.

Results

Heart rate declined progressively during AngII infusion, with males falling from 605 ± 6 beats/min to 490 ± 6 be

SUBMITTER: Manning D 

PROVIDER: S-EPMC12471107 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature