Heart rate control in patients with atrial fibrillation referred for exercise testing.

Clinical practice guidelines for patients with atrial fibrillation (AF) recommended a heart rate (HR) of 60 to 80 beats/min at rest and 90 to 115 at moderate exercise. The degree to which HR control at rest and with exercise in patients with AF complies with these recommendations is unknown. HR at rest and at peak exercise was retrospectively examined in 1,097 consecutive patients with AF referred for exercise myocardial perfusion imaging. In a subgroup of 195 patients, HR was also measured at an intermediate "moderate" level. Median HR at rest was 80 beats/min, at the upper end of the recommended range of 60 to 80. Only patients administered a beta blocker (BB; 31%) had lower (p <0.001) median HRs at rest. Median HR at moderate exercise was 128 beats/min, higher than the range of 90 to 115 recommended by the guidelines. Only patients administered a BB had significantly reduced HRs (p <0.003) at moderate exercise. Median peak exercise HR was 147 beats/min. Forty-five percent of patients exceeded their age-predicted maximal HR. Patients administered BBs were significantly less likely (p <0.01) to exceed their age-predicted maximal HR. In conclusion, in patients with AF, HR control at rest and during exercise often did not comply with guideline recommendations. Regimens including a BB were more effective in achieving HR control.