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LOINC Code 77900-9: Left ventricular Myocardial mass/Body surface area [Mass/Area] by US.2D+Calculated by area-length method

77900-9 is a LOINC code used to identify Left ventricular Myocardial mass/Body surface area [Mass/Area] by US.2D+Calculated by area-length method 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 Myocardial mass/Body surface area. It is commonly used with the system or sample type Heart.ventricle.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 Myocardial mass/Body surface area. It is commonly used with the system or sample type Heart.ventricle.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.2D+Calculated by area-length method

What it does not mean

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

Key facts

Left ventricular Myocardial mass/Body surface area [Mass/Area] by US.2D+Calculated by area-length method
Myocardial mass/Body surface area
The myocardial index is the left ventricular (LV) mass normalized for body size, which can be approximated by different measures including body surface area (BSA) and height. This term represents a BSA-based index. BSA can be calculated by a number of methods including the Mostellar and Du Bois formulas, or in some cases the average adult BSA, 1.73 m2, is used by default. The area-length formula used to calculate LV mass based on measurements taken with 2D echocardiography is as followsLV mass = 1.055 x 5/6(outer short-axis area x length + 1 cm - inner short-axis area x length). [PMID: 2936235]
2D US; Bdy surface; bod; Bodies; BSA; Calc; Calculation; CARD.US; Cardiac; Cardio; Cardiology; Echography; Heart Disease; Hrt; Hrt ventr; L; LT; LV; MAric; Myo mass; Point in time; QNT; Quan; Quant; Quantitative; Random; Sonogram; Sonograph; Sonography; Surf; ULS; Ultrasound; Ultrasound - 2-dimensional; US.2D+A-L; Ventricular

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 ventricular Myocardial mass/Body surface area [Mass/Area] by US.2D+Calculated by area-length methodLV Myo mass/BSA US.2D+A-LMyocardial mass/Body surface areaCARD.USArMassPtHeart.ventricle.left

Frequently asked questions

Code details

Code77900-9
SystemLOINC
Display nameLeft ventricular Myocardial mass/Body surface area [Mass/Area] by US.2D+Calculated by area-length method
DescriptionMyocardial mass/Body surface area
Short nameLV Myo mass/BSA US.2D+A-L
ComponentMyocardial mass/Body surface area
PropertyArMass
TimingPt
System (specimen)Heart.ventricle.left
ScaleQn
MethodUS.2D+Calculated by area-length method
ClassCARD.US
Example unitsg/m2
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.52
Last changed2.54

Part names

Myocardial mass/Body surface areaArMassPtHeart.ventricle.leftQnUS.2D+Calculated by area-length methodMass/AreaPoint in time (spot)Heart ventricle - left

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.