Incidence of Atrial Fibrillation in Relation to Changing Heart Rate Over Time in Hypertensive Patients

Abstract

Background— Onset of atrial fibrillation (AF) has been linked to changes in autonomic tone, with increasing heart rate (HR) immediately before AF onset in some patients suggesting a possible role of acute increases in sympathetic activity in AF onset. Although losartan therapy and decreasing ECG left ventricular hypertrophy are associated with decreased AF incidence, the relationship of HR changes over time to development of AF has not been examined. Methods and Results— HR was evaluated in 8828 hypertensive patients without AF by history or on baseline ECG in the Losartan Intervention for End Point Reduction in Hypertension (LIFE) study. Patients were treated with losartan- or atenolol-based regimens and followed with serial ECGs annually which were used to determine HR and ECG left ventricular hypertrophy by Cornell product and Sokolow-Lyon voltage criteria. During mean follow-up of 4.7�1.1 years, new-onset AF occurred in 701 patients (7.9%). Patients with new AF had smaller decreases in HR to last in-treatment ECG or last ECG before AF (−2.7�13.5 versus −5.2�12.5 bpm), whether on losartan- (−0.4�13.5 versus −2.2�11.7 bpm) or atenolol-based treatment (−5.3�12.8 versus −8.3�12.6 bpm, all P P Conclusion— Higher in-treatment HR on serial ECGs is associated with an increased likelihood of new-onset AF, independent of treatment modality, blood pressure lowering, and regression of ECG left ventricular hypertrophy in patients with essential hypertension.