Atrial fibrillation (AF), a common and serious cardiac rhythm disturbance, is responsible for substantial morbidity and mortality in the population. Currently about 2.3 million people in the US are diagnosed with AF and, based of the US census, this number is expected to rise to 5.6 million by 2050. It doubles in prevalence with each decade of age, reaching almost 9% at age 80–89 years. It has increased in prevalence over the calendar decades, reaching ‘epidemic’ proportions. This alarming increase in prevalence is incompletely explained by an increase in the population prevalence of elderly individuals, valve disease, heart failure or myocardial infarction. New onset AF also doubles with each decade of age, independent of the prevalence of known predisposing conditions.
Based Framingham Study data, men have a 1.5-fold greater risk of developing AF than women after adjustment for age and predisposing conditions. Of the standard cardiovascular risk factors, hypertension, diabetes and obesity are significant independent predictors of AF. Because of its high prevalence hypertension is responsible for more AF in the population (14%) than any other risk factor.
Adjusting for cardiovascular risk factors, heart failure, valvular heart disease and myocardial infarction substantially increase the likelihood of AF. Echocardiographic predictors of AF include left atrial enlargement, left ventricular fractional shortening, left ventricular wall thickness, and mitral annular calcification, offering prognostic information for AF beyond traditional clinical risk factors. Novel risk factors for AF include reduced vascular compliance, atherosclerosis, insulin resistance, environmental factors, inflammation and natriuretic peptides. There is emerging evidence that genetic variation also contributes to risk of atrial fibrillation.
The chief hazard of AF is a 4–5-fold increase in embolic stroke, assuming great importance in advanced age when it becomes a dominant factor. The attributable risk for stroke associated with AF increases steeply with age to 23.5% at age 80–89 years. AF is associated with a doubling of mortality in both sexes.
Atrial fibrillation (AF), an increasingly common dysrithmia, is responsible for substantial morbidity and mortality. Currently in the US about 2.3 million people are diagnosed with AF and, based on the US census, this number may rise to 5.6 million by 2050. Risk factors for AF include advancing age, cardiovascular disease and its risk factors. The chief hazard of AF is embolic stroke which is increased 4–5-fold, assuming great importance in advanced age when it becomes a dominant factor. AF is associated with about a doubling of mortality.