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 17985-3: Left atrial AP dimension.left atrium/AP dimension.aorta root by US

Name: LOINC Code 17985-3: Left atrial AP dimension.left atrium/AP dimension.aorta root by US
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:27.584Z

17985-3 is a LOINC code used to identify Left atrial AP dimension.left atrium/AP dimension.aorta root by US 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 AP dimension.left atrium/AP dimension.aorta root. 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 AP dimension.left atrium/AP dimension.aorta root. 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

What it does not mean

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

Key facts

Left atrial AP dimension.left atrium/AP dimension.aorta root by US
AP dimension.left atrium/AP dimension.aorta root
MC 817; this is an estimate of LA enlargement
Anterio-Posterior; Anteroposterior; AP dim.aorta root; AP dim.LA; Atrial; CARD.US; Cardiac; Cardio; Cardiology; Echography; Heart Disease; Hrt; L; LA; Length Ratio; LT; Point in time; QNT; Quan; Quant; Quantitative; Random; Sonogram; Sonograph; Sonography; 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 AP dimension.left atrium/AP dimension.aorta root by USLA AP dim.LA/AP dim.aorta root USAP dimension.left atrium/AP dimension.aorta rootCARD.USLenRtoPtHeart.atrium.left

Frequently asked questions

Code details

Code17985-3

SystemLOINC

Display nameLeft atrial AP dimension.left atrium/AP dimension.aorta root by US

DescriptionAP dimension.left atrium/AP dimension.aorta root

Short nameLA AP dim.LA/AP dim.aorta root US

ComponentAP dimension.left atrium/AP dimension.aorta root

PropertyLenRto

TimingPt

System (specimen)Heart.atrium.left

ScaleQn

MethodUS

ClassCARD.US

Example unitsratio

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0l

Last changed2.48

Part names

AP dimension.left atrium/AP dimension.aorta rootLenRtoPtHeart.atrium.leftQnUSLength RatioPoint in time (spot)Heart.atrium LeftUltrasound

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.