Syncope and Influenza B: A Case of an Arresting Association

Influenza is a contagious viral illness that usually presents with upper respiratory and pulmonary symptoms. While generally self-limited, pulmonary, renal, metabolic, neurologic, and cardiac complications have all been described in the literature. Here we describe a case of a 46-year-old male with multiple episodes of syncope, found to have severe bradycardia, sinus arrest, and positive influenza B, requiring permanent pacemaker placement. The viruses responsible for the flu can be differentiated into four types: A, B, C, and D. The two primary viruses responsible for the seasonal winter epidemic influenza in the United States are Human Influenza A and B viruses. It has been postulated that the influenza virus may be responsible for activating acute inflammatory cytokines, which then alter electrical conduction properties of endothelial cells. Although there have been cases of sinus arrest in association with influenza, some requiring pacemaker placement, our patient's presentation with multiple episodes of syncope with severe bradycardia and sinus arrest requiring permanent pacemaker placement, in association with influenza B, is very unusual and possibly unique. Since emergency physicians are at the forefront in the diagnosis, treatment, and disposition of these patients, awareness of influenza triggered cardiac events is essential and lifesaving, especially in unvaccinated patients.