[Influence of the equality of ventricular pressure in the echocardiographic determination of the ejection fraction of the left ventricle].
OBJECTIVE
Limited data have been reported concerning the influence of right ventricular systolic overload on the accuracy of the 2D echocardiographic (echo) determination of left ventricular (LV) ejection fraction (EF). The normal newborn at birth (high pulmonary peak systolic pressure) and just after the fall of pulmonary pressure, represent an in vivo model to study this influence. This study compares the LVEF determined by recommended 2D echocardiographic algorithms with that by 3D echo, in newborns at birth and just after the normal fall of right ventricular systolic pressure.


METHODS
100 echocardiographic studies (50 at 2 to 6 hours after birth--group I; and 50 at 7 to 14 days old--control group) were performed in 82 normal newborns, to determine LVEF by 4 geometric models (cylinder hemiellipsoid; ellipsoid biplane; single plane area length, in 4- and 2-chamber view; biplane method of discs) and visual estimation, using 3D echocardiography as the reference method.


RESULTS
In group I, the correlation between 3D echo and cylinder hemiellipsoid was r = 0.62 (SEE = 4.5%); ellipsoid biplane, r = 0.69 (SEE = 4.1%); single plane area length, 4 chambers, r = 0.66 (SEE = 5.1%) and, 2 chambers, r = 0.72 (SEE = 4.0%); biplane method of discs, r = 0.83 (SEE = 3.6%), and, visual estimation, r = 0.78 (SEE = 3.5%). In the control group, the correlation between 3D echo and cylinder hemiellipsoid was r = 0.70 (SEE = 3.4%); ellipsoid biplane, r = 0.63 (SEE = 3.4%); single plane area length, 4 chambers, r = 0.79 (SEE = 3.5%) and, 2 chambers, r = 0.76 (SEE = 4.1%); biplane method of discs, r = 0.90 (SEE = 2.3%), and, visual estimation, r = 0.64 (SEE = 3.9%).


CONCLUSIONS
These data suggest that the biplane method of discs and single plane area length using 2-chamber view allows a more accurate LVEF determination when significant right ventricular pressure overload is present.
Nascimento
R
R
Hospital Cruz de Carvalho, Funchal.
Freitas
A
A
Pereira
D
D
Pereira
E
E
Cardoso
A
A
Mendonça
I
I
Diniz
M
M
D000465:Algorithms; D004452:Echocardiography; D006801:Humans; D007231:Infant, Newborn; D011446:Prospective Studies; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology*; D017725:Ventricular Pressure / Q000502:physiology*
Repercussão da igualdade de pressões ventriculares na determinação ecocardiográfica da fracção de ejecção do ventrículo esquerdo.