Rare diseases · Sign or symptom
Bradycardia
Slow heartbeats
HP:0001662
What it means
A slower than normal heart rate (in adults, slower than 60 beats per minute).
Rare diseases that can present with this33
Common30–79%
9- Acitretin/etretinate embryopathy
- Apnea of prematurity
- Bohring-Opitz syndrome
- Combined oxidative phosphorylation defect type 39
- Congenitally corrected transposition of the great arteries
- GNB5-related intellectual disability-cardiac arrhythmia syndrome
- Hypothyroidism due to deficient transcription factors involved in pituitary development or function
- X-linked intellectual disability-plagiocephaly syndrome
- Yellow fever
Sometimes5–29%
19- Congenital heart block
- Congenital hypothyroidism due to maternal intake of antithyroid drugs
- Crimean-Congo hemorrhagic fever
- Encephalitis lethargica
- Familial thyroid dyshormonogenesis
- Glossopharyngeal neuralgia
- Hypothyroidism due to TSH receptor mutations
- Idiopathic congenital hypothyroidism
and 11 more in this range
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Brachycardia
Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.
Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.