Evaluation of Midwall Systolic Function in Left Ventricular Hypertrophy: A Comparison of 3-Dimensional Versus 2-Dimensional Echocardiographic Indices

This study investigated the sensitivity of 3-dimensional (3D) midwall ejection fraction (EF) (3DEF mw) to the presence of left ventricular (LV) hypertrophy (LVH) in comparison with conventional echocardiographic indices for systolic function. EF and fractional shortening (FS) do not reflect the prognosis of patients with LVH. Midwall mechanics better represent the true function in LVH. However, midwall FS (FS mw) interrogates a limited region of LV. We developed a method for determining 3DEF mw. This study compared 3DEF mw with 2-dimensional (endocardial EF [EF endo], endocardial FS, FS mw, and systolic tissue velocity) and 3D (3D EF endo and mitral annular motion [MAM]) echocardiographic indices in 28 patients with essential hypertension and LV mass index by M-mode greater than 125 g/m 2 versus 21 healthy individuals. Systolic function assessed by EF endo, endocardial FS, 3D EF endo, and systolic tissue velocity did not differ between the two groups, but MAM (11.6 vs 14.0 mm), FS mw (14.7 vs 18.2%), and 3DEF mw (36.6 vs 44.1%) were significantly decreased in LVH compared with normal. Only 3 parameters correlated significantly with both the M-mode and 3D measurements of LV mass index: FS mw ( r = −0.74 [M-mode]; r = −0.48 [3D]), 3DEF mw ( r = −0.63 [M-mode]; r = −0.68 [3D]), and MAM ( r = −0.43 [M-mode]; r = −0.36 [3D]). Midwall indices FS mw (F = 40.4) and 3DEF mw (F = 26.5) better discriminated LVH and normal groups than MAM or endocardial indices. The 3DEF mw method discriminates the systolic function of LVH and normal groups, and correlates with the degree of hypertrophy. By avoiding the limitations of FS mw or MAM, 3DEF mw provides a more comprehensive metric of systolic function in patients with LVH.