Conditions and symptoms
What Is Bradycardia? Slow Heart Rate
Bradycardia · say it: bray-dee-KAR-dee-uhAlso written: slow heart rate, slow pulse, sinus bradycardia
Short answer
Bradycardia means a slower-than-usual heart rate. It can be normal in fit people, or a side effect of some medicines.
What it means
Bradycardia means the heart is beating more slowly than usual. For some people, such as athletes or people asleep, a slow heart rate is normal and healthy. For others it can cause tiredness, dizziness, breathlessness or fainting. A very slow pulse with fainting, chest pain or confusion needs urgent medical help.
Labels list bradycardia for medicines that slow the heart, such as beta-blockers, some calcium channel blockers, digoxin and some heart rhythm medicines. The warning is telling you that the medicine can slow your pulse, and to report dizziness or fainting. Some leaflets suggest checking your pulse.
Bradycardia (slow) is the opposite of tachycardia (fast). 'Sinus bradycardia' on an ECG means the rhythm is coming from the heart's normal pacemaker, just at a slower rate.
Where you may see it
- Beta-blocker and heart medicine leaflets
- ECG reports ('sinus bradycardia')
- Hospital observation charts
📄 How it looks on a report
ECG: Sinus bradycardia, otherwise normal.
🙅 What it does not mean
- A slow pulse is not always a problem; it can be normal in fit people.
- It does not mean you should stop a heart medicine on your own.
- It is not the same as a heart block, which is a specific problem with the heart's wiring, though both can cause a slow pulse.
🎯 Check yourself
Which of these is the right meaning of “Bradycardia”?
🗒️ Questions to ask your doctor
💊 Medicines whose labels mention “Bradycardia”
Plain-English explanations of each medicine, from its official FDA label.
- Artemether and Lumefantrine
an antimalarial medicine, which is a fixed combination of two blood-stage antimalarial ingredients (artemether, an artemisinin derivative, and lumefantrine)
- Atenolol
a beta-blocker (beta-adrenergic blocker). The label describes it as a beta 1-selective, or cardioselective, blocking agent.
- Bisoprolol Fumarate
a beta-blocker, which the label describes as a synthetic, beta 1-selective (cardioselective) adrenoceptor blocking agent
- Carvedilol
A beta-blocker. The FDA lists it as both an alpha-adrenergic blocker and a beta-adrenergic blocker.
- Famotidine
A histamine-2 (H2) receptor blocker, a type of medicine that lowers stomach acid.
- Metoprolol Tartrate
A beta blocker. The label describes it as a selective beta-1 adrenergic receptor blocking agent, which means it mainly blocks beta-1 receptors, found largely in the heart.
- Phenytoin
An anti-epileptic (seizure) medicine. The label describes it as related to barbiturates in chemical structure, and it belongs to the hydantoin group of medicines.
🔗 Read more from trusted sources
- “Bradycardia” on MedlinePlus ↗
US National Library of Medicine
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