Two-dimensional echocardiography estimation of right ventricular ejection fraction by wall motion score index

Radionuclide angiography (RNA) and echocardiography (biplane Simpson method) are the most accepted methods for right ventricular ejection fraction (RVEF) evaluation. The authors tried to determine a new method to measure RVEF based on wall motion score index (WMSI).

One hundred forty-one patients with RV dysfunction had transthoracic echocardiography (TTE) evaluation of the right ventricle. In a first group of 54 patients, a correlation between RVEF using the biplane Simpson method (four chamber and two chamber [4C+2C]) and RV-WMSI was established from a polar map using an eight-segment model to find a regression equation. With the second group of 51 subsequent patients, this equation (RVEF=73.07-20.7 x WMSI), comparing the RVEF-WMSI with the biplane Simpson RVEF (4C+2C), was validated. In a third group of 36 consecutive patients with abnormal RV contractility, the RVEF was calculated by RNA and this RVEF was correlated to the RV-WMSI.

The first group of 54 patients had a correlation coefficient of 0.84 between WMSI and RVEF (biplane Simpson method). The results from the second group of 51 patients with RVEF derived from the estimated regression equation correlated well with the biplane Simpson RVEF (r=0.84). The correlation coefficient for these two groups taken together (105 patients), that is, between WMSI and RVEF (biplane Simpson method), was 0.92. The third group of 36 patients with RNA-EF displayed a correlation coefficient of 0.83 with RV-WMSI.

This new semiquantitative method for estimating RVEF from RV-WMSI is easy to use in routine TTE and shows an excellent correlation with the biplane Simpson method and RNA.