Clinical study to investigate the predictive parameters for the onset of atrial fibrillation in patients with essential hypertension

Background The risk factors involved in the onset of atrial fibrillation (A F) are well known, but the predictive clinical and paraclinical parameters for the onset of AF in hypertensive patients have not been investigated spe cifically. Methods and Results We retrospectively analyzed 97 consecutive patients wit h hypertension and no known history of AF or cardiovascular events who atte nded the cardiology outpatient clinic. The analysis was based on clinical d ata, the noninvasive ambulatory 24-hour measurement of blood pressure (AMBP ), a standard 12-lead electrocardiogram, and a Doppler echocardiogram. Afte r a mean follow-up of 25 +/- 3 months, 19 (19.5%) patients had AF, 3 (15.8% ) of whom had a cerebrovascular accident. The patients with AF were older t han the others and their AMBP showed higher mean systolic diurnal and noctu rnal blood pressures, though no differences in the clinical blood pressure readings were present. On the electrocardiogram, the maximum duration of th e P wave and its dispersion were more prolonged in the patients with AF. On the Doppler echocardiogram, left ventricular mass and left atrial dimensio n were higher in the patients with AF, and the A-wave velocity of diastolic mitral flow was reduced in these patients. In the multivariate analysis, a ge (odds ratio 3.28, P < .001), diurnal systolic blood pressure (odds ratio 1.35, P < .01) and nocturnal systolic blood pressure (odds ratio 1.16, P < .01), maximum duration of the P wave (odds ratio 2.09, P < .01), dispersio n of the P wave (odds ratio 2.52, P < .001), echocardiographic left ventric ular mass (odds ratio 1.43, P < .01), left atrial dimension (odds ratio 2.8 1, P < .001), and velocity of the A wave (odds ratio 2.24, P < .01) were in dependent predictors for the onset of AF. After correction for age, maximum duration of the P wove (odds ratio 1.34, P < .01), dispersion of the P wov e (odds ratio 1.63, P < .001), and the velocity of the A wave (odds ratio 1 .42, P < .01) remained independent predictors for the onset of AF. Conclusions In patients with hypertension, age and the level of diurnal and nocturnal systolic blood pressures measured by 24-hour AMBP are important independent predictors for the onset of AF. Independent of age, increases i n left atrial dimension and left ventricular mass, prolongation of the maxi mum duration and dispersion of the P wave and reduced A-wave velocity are a lso predictors for the onset of AF.