- BACKGROUND: Evidence of various cardiac arrhythmias in septic patients has been demonstrated by multiple clinical reports and observations. Most cardiac arrhythmias in sepsis are new-onset and may be related to sepsis-induced myocardial dysfunction. We propose to investigate and analyze data of new-onset paroxysmal atrial fibrillation (AF) in a critically ill septic population. METHODS: This is a retrospective epidemiologic study. We collected clinical data from two hundred septic patients who developed a new episode of atrial fibrillation during their hospitalization in General Intensive Care Unit (GICU) between January 2007 and June 2013. RESULTS: Of these 200 septic patients, 81 septic patients developed a new episode of AF and included in the present study. Thirty-seven patients had no past medical history of atrial fibrillation (AF) or antiarrhythmic therapy (new episode of atrial fibrillation, Group 1) and 44 had previously known episodes of atrial fibrillation and were prescribed antiarrhythmic therapy at home (Group 2). Group 2 patients had longer duration of recurrent episodes of atrial fibrillation compared to patients in Group 1 (11.07 ± 8.7 vs. 7.4 ± 6.1 days; P = 0.013). The overall ICU and in-hospital mortality rate was similar in both study groups. There was no significant difference in new stroke and pulmonary embolism (PE) between both study groups ( P > 0.05). CONCLUSION: In the present study we demonstrated no difference in morbidity and mortality rate in-ICU and after discharge between septic patients who had previous AF episodes and patients who had no previous past medical history of any cardiac arrhythmias.