What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 79977-5: Left atrial Minor axis at end systole [Length] by US.M-mode

Name: LOINC Code 79977-5: Left atrial Minor axis at end systole [Length] by US.M-mode
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:01.838Z

79977-5 is a LOINC code used to identify Left atrial Minor axis at end systole [Length] by US.M-mode 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 Minor axis.end systole. It is commonly used with the system or sample type Heart.atrium.left.

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 Minor axis.end systole. It is commonly used with the system or sample type Heart.atrium.left.

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: US.M-mode

What it does not mean

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

Key facts

Left atrial Minor axis at end systole [Length] by US.M-mode
Minor axis.end systole
Atrial; CARD.US; CARD.US.DICOM; Cardiac; Cardio; Cardiology; Echography; ES; ES minor axis; Heart Disease; Hrt; L; LA; Length; LT; MM; mmode; Point in time; QNT; Quan; Quant; Quantitative; Random; SAX; short axis; Sonogram; Sonograph; Sonography; Sys; Syst; ULS; Ultrasound

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

Left atrial Minor axis at end systole [Length] by US.M-modeLA ES minor axis M-modeMinor axis.end systoleCARD.US.DICOMLenPtHeart.atrium.left

Frequently asked questions

Code details

Code79977-5

SystemLOINC

Display nameLeft atrial Minor axis at end systole [Length] by US.M-mode

DescriptionMinor axis.end systole

Short nameLA ES minor axis M-mode

ComponentMinor axis.end systole

PropertyLen

TimingPt

System (specimen)Heart.atrium.left

ScaleQn

MethodUS.M-mode

ClassCARD.US.DICOM

Example unitscm

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.54

Last changed2.54

Part names

Minor axis.end systoleLenPtHeart.atrium.leftQnUS.M-modeMinor axis at end systoleLengthPoint in time (spot)Heart.atrium LeftUltrasound.M-mode

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.