Atrial fibrillation is the most common cardiac arrhythmia and it causes substantial morbidity, especially in elderly people. In June 2006, the UK National Institute for Health and Clinical Excellence (NICE) published new guidelines for control of heart rate in people with chronic atrial fibrillation.1 The guidelines depart from historical practice by recommending that instead of digoxin, β adrenoceptor blockers or rate limiting calcium antagonists should be the preferred initial monotherapy, except in predominantly sedentary people. Similarly, the revised 2006 joint American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) guidelines recommend the use of β blockers or calcium antagonists alone to control heart rate.2 We have reviewed the evidence to support this fundamental change in practice and challenge its safety.

No single definition of ideal control of heart rate in chronic atrial fibrillation exists.3 Rate control drugs aim to reduce heart rate at rest and during exercise, without causing excessive nocturnal bradycardia. The ultimate aim of treatment is to improve symptoms and exercise tolerance, and to prevent cardiomyopathy induced by tachycardia. To reduce morbidity, the benefits of treatment need to be weighed against the harms. A substudy of the atrial fibrillation follow-up investigation of rhythm management (AFFIRM) study found no association between achieved ventricular rate and overall survival or quality of life.4

Epidemiological studies in the United Kingdom and the United States have reported an overall decline in the use of …