Medically reviewed by Dr Nabila Laskar, Consultant Cardiologist (GMC 7040901). Bradycardia means a resting heart rate below 60 beats per minute. In athletes it is often entirely normal; in others it can reflect disease of the heart's electrical system.
Well-trained athletes and many healthy people have resting rates in the 40s or 50s, and rates fall further during sleep. A slow rate that rises appropriately with exercise and causes no symptoms is generally not a concern.
Fatigue, breathlessness on exertion, dizziness, near-fainting or fainting (see /conditions/syncope-fainting), or a heart rate that fails to increase with activity all warrant investigation.
Sinus node dysfunction, heart block, medication such as beta blockers and rate-limiting drugs, an underactive thyroid, electrolyte disturbance, sleep apnoea and previous cardiac surgery. Never stop or change prescribed medication yourself.
A 12-lead ECG plus 24-hour to 7-day Holter monitoring (see /conditions/holter-monitor) establishes the rhythm and correlates it with symptoms, alongside an echocardiogram and blood tests. Treatment addresses reversible causes first; a permanent pacemaker is considered for symptomatic conduction disease.
Not necessarily. In a fit person with no symptoms and a normal rise in rate on exertion, it can be entirely normal. The same rate accompanied by dizziness, fatigue or blackouts needs prompt assessment with an ECG and Holter monitor.
Yes. Pauses or heart block can reduce blood flow to the brain and cause light-headedness or blackouts. Fainting without warning, or fainting during exertion, should be assessed urgently.
No. Pacemakers are reserved for symptomatic bradycardia or specific types of heart block. Many people need no treatment beyond monitoring, and some improve once a contributing medication or thyroid problem is addressed.
Yes — beta blockers, certain calcium channel blockers, some antiarrhythmics and a number of eye drops can all slow the heart. Any adjustment must be made by your prescribing doctor, not independently.