Assessment of proximal isovelocity surface area (PISA) shape using three-dimensional echocardiography in a paediatric population with mitral regurgitation or ventricular shunt.
BACKGROUND
The proximal isovelocity surface area (PISA) method is validated to quantify mitral regurgitation (MR) and ventricular shunt (VS). However, the two-dimensional echocardiography (2DE) PISA method assumes a hemispherical distribution of velocity factors proximal to the MR or VS orifice.


OBJECTIVE
To assess the PISA shape by three-dimensional echocardiography (3DE) in a paediatric population with MR or VS. According to the true PISA shape, we suggest different models to calculate the MR or VS volume by the 3DE PISA method.


METHODS
Thirty-one paediatric patients (aged 1month to 20years, median 69months) were included: 17 had MR and 14 had VS. The orifice area and volume of MR and VS were evaluated by 2DE. 3DE acquired the entire PISA volume at orifice level. The PISA shape was estimated according to three diameters as being hemispherical, prolate hemispheroid, oblate hemispheroid and hemiellipsoid.


RESULTS
Data from 28patients were analysed. The PISA shape was variable: hemispherical, 11%; prolate hemispheroid, 43%; oblate hemispheroid, 32%; hemiellipsoid, 14%. Oblate hemispheroids occurred more frequently in the MR group (47%), whereas prolate hemispheroids occurred more frequently in the VS group (62%); hemispheres were scarce in both groups (10%). The mean MR or VS orifices and volumes measured by 2DE and 3DE were significantly different (0.123cm(2) versus 0.094cm(2) and 13.2mL versus 10.1mL, respectively; p=0.019).


CONCLUSIONS
3DE describes the true surface of the PISA shape. In a paediatric population with MR or VS, the PISA is rarely hemispherical but is more often prolate or oblate hemispheroid.
Cardiologie pédiatrique, hôpital des Enfants, 330, avenue de Grande-Bretagne, 31000 Toulouse, France.
Abdelkader Boutaleb
AB
Ziani
Decebal Gabriel
DG
Latcu
Sylvia
S
Abadir
Soizic
S
Paranon
Yves
Y
Dulac
Felipe
F
Guerrero
Philippe
P
Acar
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018618:Echocardiography, Doppler, Color; D019560:Echocardiography, Three-Dimensional; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008955:Models, Cardiovascular; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D016276:Ventricular Function; D055815:Young Adult