Estimation of right ventricular mass by two-dimensional echocardiography.
BACKGROUND
This report describes two original echocardiographic approaches to measure right ventricular (RV) mass (RVM).


METHODS
In the bullet formula (5/24 pi D1 D2 L), where D1 and D2 are short axes and L the log axis, the RVM is obtained by subtracting the cavity volume from the RV total volume and subsequently multiplying the difference by myocardium density. The second method uses 3 endocardium segments measured at: (1) short axis plane of the aortic valve and left atrium (b1); (2) short axis plane at the midpoint between the tricuspid valve annulus and the apex (b2); and (3) 4-chamber view (h). Those segment lengths are applying in the formula A = [(b1 + b2)/2] x h. The result is multiplied by the wall thickness and by myocardium density.


RESULTS
Both formulas were primarily tested in 30 mongrel dogs and have shown good correlation with the true mass ( r = 0.869 with the segments formula and r = 0.819 with the bullet formula). The same method was used in 20 human patients before heart transplant with similar results ( r = 0.810 with the segments formula and r = 0.836 with the bullet formula).


CONCLUSIONS
The RVM can be satisfactorily estimated by 2-dimensional echocardiography. The linear regression between the calculated mass (using the smoothest and thinner myocardium thickness) and the actual mass may provide the correction factor for the RVM calculation. Two echocardiographic methods were used to measure right ventricular mass. One of them used a bullet formula variant (5/24 pi D1 D2 L). The second method used 3 endocardium segments measured in 3 2-dimensional echocardiographic planes (short axis of aortic valve and left ventricle, and 4-chamber view), and applied in the formula A = [(b1 + b2)/2] x h. Both formulas have shown good correlation with the true mass in 30 mongrel dogs ( r = 0.869 with the segments formula and r = 0.819 with the bullet formula) and in 20 human patients before heart transplant ( r = 0.810 and r = 0.836, respectively).
Pontes
Sergio C
SC
Section of Cardiovascular Diagnostic Methods, Instituto Dante Pazzanese de Cardiologia, São Paulo, Brazil. scponte@attglobal.net
Assef
Jorge E
JE
Barretto
Rodrigo B M
RB
Chaccur
Paulo
P
Moreira
Dalmo A R
DA
Da S Nina
Vinicius José
VJ
Nunes
Frederico
F
Melani
Roberto H
RH
Correia
Edileide B
EB
Dinkuisen
Jarbas
J
Sousa
Amanda M R
AM
D000818:Animals; D004285:Dogs; D004452:Echocardiography / Q000379:methods; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D016014:Linear Models