{"doi":"10.1016/j.jacep.2025.06.007","title":"Microvascular Rarefaction in the Sinoatrial Node","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: ), whereas vessels in the inferior SA node remained unchanged. Despite preserved myocyte density, these changes were accompanied by up-regulation of oxidative stress and the hypoxia-inducible factor 1α and vascular endothelial growth factor signaling pathways. CONCLUSIONS: These findings highlight microvascular rarefaction in the superior SA node as a key early event in HFpEF pathology. The loss of redundant vascular loops compromises metabolic support for pacemaking, illustrating a broader principle: rarefaction can impair excitability in metabolically demanding excitable tissues.","journal":"JACC. Clinical electrophysiology","year":2025,"id":521698,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":5,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9669,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1217934,"name":"Ernesto J Rivera","orcid":null,"position":1,"is_corresponding":false},{"id":1046972,"name":"Paula Rhana","orcid":null,"position":2,"is_corresponding":false},{"id":458956,"name":"Collin Matsumoto","orcid":"0000-0002-5370-1156","position":3,"is_corresponding":false},{"id":1077924,"name":"Zhihui Fong","orcid":"0000-0002-0521-0088","position":4,"is_corresponding":false},{"id":310949,"name":"Phung N. Thai","orcid":"0000-0001-7344-150X","position":5,"is_corresponding":false},{"id":990177,"name":"Manuel F. Muñoz","orcid":"0000-0001-7024-9600","position":6,"is_corresponding":false},{"id":298619,"name":"Jorge E. Contreras","orcid":"0000-0001-9203-1602","position":7,"is_corresponding":false},{"id":1392590,"name":"Sei Kim","orcid":"0009-0009-6757-7422","position":8,"is_corresponding":false},{"id":433645,"name":"Nathan Grainger","orcid":"0000-0002-3954-7041","position":9,"is_corresponding":false},{"id":310948,"name":"Nipavan Chiamvimonvat","orcid":"0000-0001-9499-8817","position":10,"is_corresponding":false},{"id":1158149,"name":"Geoanna Bautista","orcid":"0000-0003-0245-9272","position":11,"is_corresponding":false},{"id":355960,"name":"Luis F. Santana","orcid":"0000-0002-4297-8029","position":12,"is_corresponding":false},{"id":953056,"name":"Declan Manning","orcid":"0009-0001-4107-4829","position":0,"is_corresponding":true}],"reference_count":67,"raw_metadata":null,"created_at":"2026-07-19T02:49:49.198144Z","pmid":"40704959","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}