Abstract
Background: Atrial flutter (AFL) and atrial fibrillation (AF) are the most common atrial tachyarrhythmias. The conditions leading to the onset of one of these arrhythmias over the other remain largely unknown.
Methods: To determine and compare the prevalence of known risk factors for cardiovascular disease among unselected individuals presenting with their first ever episode of AFL or AF, we evaluated 11 pre-selected clinical variables including age, sex, stroke, myocardial infarction, congestive heart failure (CHF), hypertension, rheumatic heart disease, smoking, chronic obstructive pulmonary disease (COPD), diabetes and thyroid abnormality. Using the resources of the Marshfield Epidemiologic Study Area, a database that captures nearly all medical care among its nearly 60,000 residents, all newly diagnosed cases of either AFL or AF in the region during a 4-year period were identified. Fischer’s exact test was performed to compare the difference between AFL patients and AF patients for each of the 11 above-mentioned clinical characteristics. Multivariate logistic regression analysis was performed to obtain odds ratio (OR) and corresponding 95% confidence interval (CI) for the status of AFL for each preexisting comorbidity, with adjustment for age and gender.
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 COPD (25% vs. 12%, P=0.006) and CHF (28% vs. 17%, P=0.05). Hypertension on the other hand, was more common among individuals with AF (63% vs. 47%, P=0.01). After adjusting for age and gender, patients with AFL as opposed to those with AF had higher odds for having a history of COPD (OR 2.34, 95% CI 1.26–4.32, P=0.007), CHF (OR 2.00, 95% CI 1.12–3.58, P=0.019), and lower odds of hypertension (OR 0.56, 95% CI 0.34–0.93, P=0.025). These statistically significant associations persisted even with COPD, CHF, and hypertension simultaneously included in a multivariate logistic regression model, in addition to age and gender.
Conclusions: This study represents the first report to evaluate potential differences in the conditions associated with the development of AFL versus AF in man. This study raises an important question regarding the role of COPD and hypertension playing a role in initiation and maintenance of AFL and AF, respectively by their selective influence on the right atrial and left atrial dynamics, respectively.
- Received September 11, 2008.
