Atrial Fibrillation in Hypertension

Incidence, determinants, and outcome of atrial fibrillation in hypertensive subjects are incompletely known. We followed for up to 16 years 2482 initially untreated subjects with essential hypertension. At entry, all subjects were in sinus rhythm. Subjects with valvular heart disease, coronary artery disease, preexcitation syndrome, thyroid disorders, or lung disease were excluded. During follow-up, a first episode of atrial fibrillation occurred in 61 subjects at a rate of 0.46 per 100 person-years. At entry, subjects with future atrial fibrillation differed (all P<0.05) from those without by age (59 versus 51 years), office, and 24-hour systolic blood pressure (165 and 144 versus 157 and 137 mm Hg, respectively), left ventricular mass (58 versus 49 g/heightm(2.7)), and left atrial diameter (3.89 versus 3.56 cm). Age and left ventricular mass (both P<0.001) were the sole independent predictors of atrial fibrillation. For every 1 standard deviation increase in left ventricular mass, the risk of atrial fibrillation was increased 1.20 times (95% CI, 1.07 to 1.34). Atrial fibrillation became chronic in 33% of subjects. Age, left ventricular mass, and left atrial diameter (all P<0.01) were independent predictors of chronic atrial fibrillation. Ischemic stroke occurred at a rate of 2.7% and 4.6% per year, respectively, among subjects with paroxysmal and chronic atrial fibrillation. These data indicate that in hypertensive subjects with sinus rhythm and no other major predisposing conditions, risk of atrial fibrillation increases with age and left ventricular mass. Increased left atrial size predisposes to chronicization of atrial fibrillation.