PROJECT SUMMARY The purpose of this Ruth L. Kirschstein National Research Service Award (NRSA) Individual Pre-Doctoral Fellowship in Nursing Research (F31) application is to provide research training for Ms. Frazier, a third-year doctoral student at the University of Washington School of Nursing. The long-term goal of this training is for this applicant to develop into an independent nurse scientist in a research-intensive academic setting with a program of research dedicated to interventions that integrate biological and socioecological factors to reduce and ameliorate symptom burden in individuals living with atrial fibrillation (AF). As the U.S. population ages, the number of individuals with AF is rapidly increasing, with cases projected to more than double by 2030. Most individuals with AF experience bothersome and at times debilitating symptoms that significantly impair quality of life (QOL). Women with AF bear the burden of more frequent and severe AF symptoms and lower QOL. While prior studies have consistently identified gender differences in AF symptom and QOL outcomes, the multilevel factors contributing to such differences in women and men are largely understudied. The applicant proposes a cross-sectional study (N=124) that employs both quantitative (Aims 1 and 2) and qualitative (Aim 3) methods to elucidate social factors and novel biological markers that contribute to differences in AF symptoms and QOL in women and men with AF. The specific aims are to: 1) Compare epicardial adipose tissue volume, adipokines (leptin and adiponectin), AF symptoms, and QOL between women and men with AF; 2) Examine for associations linked to potential intermediating pathways between epicardial adipose tissue volume, adipokines (leptin and adiponectin), AF symptoms, and QOL for women and men with AF; and 3) Explore perceptions of social factors (social support, living situation, and social network interactions) and their influence on AF symptoms and QOL for women and men with AF. Through advanced coursework and direct research experience, qualitative and quantitative methods, focused analysis of gender and social contexts in AF, and discovery of highly relevant links among biological markers of and AF-related outcomes, this award will provide a firm foundation for the long-term goal to develop behavioral interventions and upstream solutions to improve symptom experiences and QOL in women and men with AF.