Rate control in atrial fibrillation: looking beyond the average heart rate.
OBJECTIVE
The aim of this article is to provide a perspective on rate control in atrial fibrillation which emphasizes patient wellbeing (exercise tolerance, symptoms, quality of life) over attempts to reduce resting or exercise heart rate to an arbitrary range.


RESULTS
Recent trials of rhythm versus rate control strategies of treatment in patients with atrial fibrillation suggest that rate control is a viable first line strategy in many patients. The adverse consequences of atrial fibrillation with rapid ventricular response are partly due to factors other than rate itself, such as irregularity of ventricular response, and variable changes in autonomic nervous system output. Digoxin, calcium channel blockers, and beta-blockers cause a similar reduction in resting heart rate. Beta blockers are the most potent at reducing exercise heart rate, followed by calcium channel blockers and digoxin. Exercise tolerance is occasionally improved by digoxin, sometimes improved by calcium channel blockers and not improved by (and sometimes decreased by) beta-blockers. Information about quality of life with different rate control regimens is sparse.


CONCLUSIONS
Rate control in atrial fibrillation provides important benefits to patients in terms of symptoms, quality of life and prevention of late consequences of uncontrolled rate (such as tachycardia induced cardiomyopathy). Restricting treatment objectives to achievement of a specific heart rate range on resting or exercise electrocardiogram may result in lack of patient benefit or worsened symptoms. Understanding the nuances of rate control when treating individual patients and interpreting existing evidence allows patients to experience the most benefit from this treatment strategy.
Division of Cardiology, St Michael's Hospital and University of Toronto, Toronto, Ontario, Canada.
Kamran
K
Ahmad
Paul
P
Dorian
D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology; D004562:Electrocardiography / Q000187:drug effects*; D015444:Exercise / Q000502:physiology / Q000523:psychology; D006333:Heart Failure / Q000188:drug therapy / Q000503:physiopathology / Q000523:psychology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012146:Rest / Q000502:physiology / Q000523:psychology
D000889:Anti-Arrhythmia Agents