Atrial flutter versus atrial fibrillation in a general population: differences in comorbidities associated with their respective onset.

Objective: Determine and compare the prevalence of known risk factors for cardiovascular disease among unselected individuals presenting with their first ever episode of atrial flutter (AFL) and atrial fibrillation (AF).

Study Design And Setting: We evaluated 11 pre-selected clinical variables including age, sex, smoking history and other potential cardiac risk factors. Using the resources of the Marshfield Epidemiologic Study Area, a population-based database, all newly diagnosed cases of either AFL or AF in the region during a 4-year period were identified.

Results: Among the 472 incident cases, 76 (16.1%) had AFL and 396 (83.9%) had AF. Compared to those with AF, subjects with AFL were more likely to have had a history of chronic obstructive pulmonary disease (25% vs. 12%, P = 0.006), heart failure (28% vs. 17%, P = 0.05), and smoking (49% vs. 37%, P = 0.06). Hypertension, on the other hand, was more common among individuals with AF (63% vs. 47%, P = 0.01).

Conclusion: This study represents the first report to evaluate potential differences in the conditions associated with the development of AFL versus AF. Research into the mechanisms of atrial arrhythmogenesis may lead to improved preventive and therapeutic interventions.