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Term Description

The effective regurgitant orifice area (EROA) is the size of the defect where the valve leaflets are not aligning normally (coaptation defect). The severity of regurgitation is related to the EROA. Proximal isovelocity surface area (PISA) is a method for calculating the EROA using color flow Doppler and is based on flow dynamics and the continuity principle, which states that in the absence of a leak or additional flow into a conduit, the flow rate will be constant along the length of the conduit, whether the conduit is the heart or the regurgitant jet. The EROA is calculated from the flow and peak velocity at the regurgitant orifice, where the flow is based on the radius at the orifice and the Nyquist limit (aliasing velocity), which is the velocity at which the color flow switches from red to blue or blue to red, and the peak velocity is measured using continuous wave Doppler of the jet. PMID: 17898369

The Proximal Isovelocity Surface Area (PISA) method is based on convergent flow dynamics and the Continuity Principle. Proximal to the orifice, flow converges in hemispheric layers of equal velocity. The flow rate across any of these hemispherical isovelocity surfaces is equal to the area of the surface (which can be calculated from its radius) multiplied by the flow velocity at the surface. Choosing a PISA velocity equal to the aliasing velocity of the system is an easy way to visualize an isovelocity surface (which will appear as the surface where the Doppler color switches between red and blue) and measure the corresponding PISA radius from the center of the orifice to the surface. The Continuity Principle states that in the absence of a leak or additional flow into a conduit, the flow rate will be constant along the length of the conduit, whether the conduit is the heart or the regurgitant jet. So the flow rate through the regurgitant orifice is the same as the flow rate across the PISA surface. Dividing the flow rate by the peak velocity through the orifice (measured using continuous wave Doppler of the regurgitant jet) provides the effective regurgitant orifice area (EROA).
Source: DICOM

Part Description

LP72534-8   Effective regurgitant orifice area
Cardiac valve area can be measured (orifice area) or indirectly calculated (effective orifice area). Direct measurement can be done on echo, and calculations are based on other measurements such as blood flow volume and velocity. [DICOM] The effective orifice area is calculated based on the equation F=A×V, where F is flow, A is area and V is velocity. The velocity is measured directly with Doppler echo and indirectly during cardiac catheterization based on the Torricelli law from the transvalvular pressure gradient: V=√2gh, where g is the velocity of acceleration resulting from gravity and h is the pressure gradient. Therefore, for area as measured by cardiac catheterization, the formula is A=F/√2gh. PMID: 22547754 Source: Regenstrief LOINC, PMID: 22547754

LOINC Names Get Info

Fully-Specified Name
Effective regurgitant orifice area:Area:Pt:Aortic valve:Qn:US.doppler+Calculated by PISA method
Long Common Name
Aortic valve Effective regurgitant orifice area by US.doppler+Calculated by PISA method
Short Name
AV EROA PISA

Part Model Get Info

  • Component
    Effective regurgitant orifice area
    LP72534-8
    • Analyte
      Effective regurgitant orifice area
      LP72534-8
      • Component Numerator
        Effective regurgitant orifice area
        LP72534-8
        • Component Numerator Core
          Effective regurgitant orifice area
          LP72534-8
        • Component Numerator Core Suffix
          NULL
           
      • Component Denominator
        NULL
         
        • Component Denominator Core
          NULL
           
        • Component Denominator Core Suffix
          NULL
           
    • Challenge
      NULL
       
    • Adjustment
      NULL
       
    • Count
      NULL
       
  • Property
    Area
    LP6782-9
  • Time
    Pt
    LP6960-1
  • System
    Aortic valve
    LP7026-0
    • System Core
      Aortic valve
      LP7026-0
    • Super System
      NULL
       
  • Scale
    Qn
    LP7753-9
  • Method
    US.doppler+Calculated by PISA method
    LP191891-3

Basic Attributes

Class
CARD.US
Type
Clinical
First Released
Version 2.52
Last Updated
Version 2.56 (NAM)
Change Reason
Added "area" to the Component to align with the other effective orifice terms
Order vs. Observation
Observation

Formula (Readable)

Effective regurgitant orifice area (EROA) = [(2 x Pi x r^2) x Nyquist limit]/Vmax

Language Variants Get Info

TagLanguageTranslation
el-GRGreek (Greece)Επιφάνεια αποτελεσματικού στομίου παλινδρόμησης:Επιφάνεια:Pt:Αορτική βαλβίδα:Qn:Υπερηχογράφημα.doppler+Υπολογιζόμενο με τη μέθοδο PISA
Synonyms: CARD.US Pt Qn Αορτική βαλβίδα Επιφάνεια Επιφάνεια αποτελεσματικού στομίου παλινδρόμησης Επιφάνεια στομίου παλινδρόμησης ΗΠΑ Περιοχή στομίου Υπερηχογράφημα.doppler Υπερηχογράφημα.doppler.υπολογιζόμενο Υπερηχογράφημα.doppler+Υπολογιζόμενο με τη μέθοδο PISA Υπολογιζόμενο
es-MXSpanish (Mexico)Área de orificio regurgitante eficaz:Zona:Punto temporal:Valvula aortica:Cuantitativo:US.doppler+Calculated by PISA method
it-ITItalian (Italy)Area orifizio rigurgitante effettivo:Area:Pt:Valvola aortica:Qn:Eco.doppler+Calcolato da metodo PISA
Synonyms: Eco Ecografia cardiaca Ecografia.doppler Ecografia.doppler.calcolata Punto nel tempo (episodio)
zh-CNChinese (China)有效反流口:面积:时间点:主动脉瓣:定量型:超声.多普勒+近端等速表面积计算法
Synonyms: 反流（回流、返流、回流性、反流性、逆流、反逆）口（孔、孔口、出口、瓣口）面积（大小） 口（孔、孔口、出口、瓣口）面积 可用数量表示的;定量性;数值型;数量型;连续数值型标尺 孔;孔口;出口;瓣口 心脏病学 心脏病学.超声;心脏超声 心脏超声.多普勒 心脏超声.多普勒.计算法 时刻;随机;随意;瞬间 有效反流（回流、返流、回流性、反流性、逆流、反逆）口（孔、孔口、出口、瓣口） 计算;计算型方法 超声.多普勒+近端等速表面积（Proximal Isovelocity Surface Area、PISA）计算法 超声检查方法;超声检查法;超声波;超声波检查方法;超声波检查法 近端等速表面积 近端等速表面积（Proximal Isovelocity Surface Area，PISA）

Example Units

UnitSource
cm2Example UCUM Units

LOINC Terminology Service (API) using HL7® FHIR® Get Info

CodeSystem lookup
https://fhir.loinc.org/CodeSystem/$lookup?system=http://loinc.org&code=77909-0