LOINCActiveObservation

LOINC Code 10121-2: ST wave mid displacement in lead I

10121-2 is a LOINC code used to identify ST wave mid displacement in lead I in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component ST wave displacement.mid.lead I. It is commonly used with the system or sample type Heart.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component ST wave displacement.mid.lead I. It is commonly used with the system or sample type Heart.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Observation
  • Method: EKG

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

  • ST wave mid displacement in lead I
  • ST wave displacement.mid.lead I
  • Cardiac; Cardio; Cardiology; ECG; EKG.MEASUREMENTS; Eklund; Electrical potential; Electrocardiogram; Electrocardiograph; Heart Disease; Hrt; Painter's colic; PB; Plumbism; Point in time; QNT; Quan; Quant; Quantitative; Random; ST wave MD L-I; Voltage

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

ST wave mid displacement in lead IST wave MD L-IST wave displacement.mid.lead IEKG.MEASElpotPtHeart

Frequently asked questions

Code details

Code10121-2
SystemLOINC
Display nameST wave mid displacement in lead I
DescriptionST wave displacement.mid.lead I
Short nameST wave MD L-I
ComponentST wave displacement.mid.lead I
PropertyElpot
TimingPt
System (specimen)Heart
ScaleQn
MethodEKG
ClassEKG.MEAS
Example unitsmV
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0i
Last changed2.48

Part names

ST wave displacement.mid.lead IElpotPtHeartQnEKGElectrical Potential (Voltage)Point in time (spot)Electrocardiogram (EKG)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

LOINC Code 10121-2 | HealthAssure