Étude de la fonction ventriculaire droite par 2D speckle imaging et échographie tridimensionnelle. Comparaison à l’IRM myocardique

Purpose

The echocardiographic assessment of right ventricular (RV) function requires many different parameters. We studied and compared with magnetic resonance imaging (MRI) two markers of RV function derived from new imaging tools: 2D speckle imaging (2DSI) and three dimensional echography.

Methods and results

Thirty-two patients (19 with RV ejection fraction RVEF] ≤ 45%) underwent both complete echocardiography - including standard parameters of RV function (fractional area change FAC], Tei index, systolic velocity of tricuspid annulus by DTI), 3D full-volume acquisition on RV - and MRI for the evaluation of RV volumes and RVEF. 2DSI was applied to high frame rate cine loops centred on the RV free wall with measurement of peak systolic strain (%) in the basal, median and apical segments of this wall. Strain, especially in RV median and apical segments, is reduced in patients with RVEF less or equal to 45% (median strain: −16,39 ± 5,27 vs. −24,74 ± 8,00 p = 0,002]; apical strain −13,01 ± 6,84 vs. 22,53 ± 11,32 p = 0,03]) with a very good correlation with RVEF (r = −0,717, p = 0,0001) but also with the usual echographic parameters of RV function, (FAC: r = 0,019; Tei: r = 0,01; peak systolic velocity: r = 0,002). The 3D RVEF is also but poorly correlated with MRI RVEF, (r = 0,447, p = 0,017). Furthermore, 3D significantly underestimated RV volumes. By multivariate analysis, apical strain (p = 0,004) and FAC (p = 0,029) were predictive of a decreased RVEF.

Conclusion

Apical strain as measured from 2DSI seems a promising parameter in the estimation of RV function. 3D estimation of RVEF is more disappointing because of an important underestimation of RV volumes.