PO-02-145 SPATIAL TRANSCRIPTOMICS IN THE HUMAN PULMONARY VEIN SLEEVE

AF is often treated by ablation to isolate the pulmonary veins where ectopic pacemaker activity or reentry may initiate AF. The relationship of gene expression and histology in vein unknown. To identify sections regions be indicative pathogenesis. Human (PV) sleeve tissues form ostia left atrium were obtained from 8 unused lung heart transplant donors a protocol approved Cleveland Clinic IRB. After tissue sectioning staining, spatial RNAseq was performed using 10x Genomics Visium platform. mRNAs from∼1000 2500 genes sequenced each area. Seurat clustering yielded 15 different clusters. These split into two segregating populations, with one connecting population. Multiple cells cell types reside 55 μm diameter A clear asymmetry clusters observed PV sections. Cell-type marker derived published human single nuclei used determine dominant One group enriched cardiomyocytes, while other for including fibroblasts, vascular smooth muscle cells, endothelial adipocytes. Spatial transcriptomics clearly resolved venous, cardiomyocyte, epicardial (Figure, showing UMAP specimens), as well fibrotic regions. AF-associated PITX2, SHOX2, HCN4 also mapped, confirming higher cardiac master transcription factor SHOX2 vs. atrial appendage (LAA) tissues. Expression hyperpolarization-activated ion channel sporadic both LAA specimens. identified profiles easily identifying venous muscle, layers. predominant type region leveraging data. help discover associated PV.