C0801549
R wave axis.horizontal plane:Angle:Pt:Heart:Qn:EKG
Concept
CUIC0801549
PreferredR wave axis.horizontal plane:Angle:Pt:Heart:Qn:EKG
Cross-maps
LOINC18508-2
Source vocabularies
Atoms not loaded for this concept.
# same page, as API
GET api.autoicdapi.com/v1/reference/umls/C0801549
GET api.autoicdapi.com/v1/translate?code=C0801549&from=umls&to=snomed-ct
UMLS C0801549, plainly answered
What is UMLS code C0801549?
UMLS CUI C0801549 is "R wave axis.horizontal plane:Angle:Pt:Heart:Qn:EKG".
Which terminologies does UMLS C0801549 bridge?
R wave axis.horizontal plane:Angle:Pt:Heart:Qn:EKG (CUI C0801549) groups: 1 LOINC code.
What is UMLS?
The Unified Medical Language System is the NLM's meta-terminology that unifies SNOMED CT, ICD-10, ICD-11, RxNorm, LOINC, MeSH, and around 200 other source vocabularies under a single concept identifier (CUI). One UMLS CUI can group dozens of synonymous codes from different terminologies.
What is a CUI and why does it matter?
A CUI is a stable identifier (like C0011860) that points at a single clinical idea regardless of how that idea is encoded in any specific vocabulary. CUIs are the most reliable way to bridge between terminologies when you need to compare or merge data from multiple sources.
How does UMLS help with cross-mapping?
Every UMLS concept page lists the codes it groups together. That gives you a free crosswalk: a SNOMED concept and an ICD-10 code that share a CUI describe the same clinical idea. Our cross_references API returns these groupings inline.
Is the API free to use?
Browsing the directory is free. Programmatic /v1/reference/umls/* access needs an API key. Production volume requires a paid tier.
How fresh is the UMLS data?
We track NLM's twice-yearly releases (May AB and November AB). Each release brings new concepts, retirements, and atom updates from the source vocabularies, and our index reflects them within the same week.
Do I need a UMLS license?
Yes. The UMLS Metathesaurus License Agreement is free but requires an NLM UTS account. Customers in production need their own license. Free-tier evaluation use is permitted under the standard terms.