Introduction: We conducted an instrumental variable analysis to test whether acute alcohol consumption leads to increased emergency department (ED) visits for AF at the level of the general population. Methods: We analyzed blood alcohol concentration measurements obtained from individuals using commercially available Bluetooth-enabled breathalyzer devices (BACtrack, San Francisco, CA) collected between January 1, 2014 and December 31, 2016 to identify dates associated with heightened alcohol consumption that corresponded to recurrent, nationally-recognized events. Outcomes included ED visits with AF (main analysis) or supraventricular tachycardia (SVT; as a negative control) in California between January 1, 2005 to December 30, 2015 using Office of Statewide Health Planning and Development data. A secondary analysis examining rates of new-onset AF was conducted. We utilized population denominators for age, sex, and race/ ethnicity in California from the US Census. Multivariable adjusted Poisson regression models were utilized to compare rates of AF during and 6 days following instrumental events compared to all other days of the year. Results: Using 1,269,054 breath alcohol measurements obtained from 36,158 individuals, we identified 8 recurring events associated with heightened alcohol consumption. After multivariable adjustment, excess alcohol consumption inferred from our instrumental variables was associated with 719 additional AF visits per 100,000 person-years (95% CI 189-1249, p = 0.008; Table ). The association between these events and new-onset AF exhibited a stronger effect (1,757 additional visits, 95% CI 945-2,569, p < 0.001). A negative control analysis failed to exhibit significantly heightened rates of SVT during those same dates. Conclusion: These data suggest that acute alcohol consumption is associated with a higher risk for discrete AF episodes, as well as for new-onset (incident) AF, in the general population.