Layer-specific deformation analysis in severe aortic valve stenosis, primary mitral valve regurgitation, and healthy individuals validated against invasive hemodynamic measurements of heart function.

Abstract

Speckle tracking echocardiography is considered valuable in assessing left ventricular (LV) function. The method has been refined to assess deformation in different myocardial layers, but the effect of volume vs pressure overload on this pattern is unknown. The aim was to test whether layer-specific myocardial strain (LSS) obtained by speckle tracking echocardiography exhibits different patterns in conditions with different loading conditions. Forty patients with asymptomatic severe aortic stenosis (AS) (AVA 0.81±0.15cm2 , LV ejection fraction [LVEF] 66%±7%), 43 patients with asymptomatic or mildly symptomatic significant primary mitral regurgitation (MR) (effective regurgitant orifice (ERO) 0.51 (IQR 0.37-0.67)cm2 , LVEF 70%±7%), and 23 healthy individuals (LVEF 65%±6%) were enrolled. Echocardiography and right heart catheterization were performed in all patients. In MR, strain values in each myocardial layer (endocardial/global longitudinal strain (GLS)/epicardial) were higher (25.0%±3.4%/21.6%±2.9%/18.8%±2.6%) compared to healthy individuals (22.6%±3.2%/19.6%±2.9%/17.1%±2.6%) and AS (20.5%±2.8%/17.7%±2.5%/14.0%±5.6%), P<.001. All 3 groups exhibited a similar LSS pattern with highest values in the endocardial and lowest values in the epicardial layer. The epicardial-endocardial strain ratio was lower in AS (0.72±0.04) than in MR (0.75±0.04, P=.04). Global longitudinal strain (GLS) correlated significantly with LV wall stress (r=.39, P=.0003) but not with LV stroke work or contractility. Layer-specific myocardial strain (LSS) patterns differed in patients with severe AS, significant MR, and healthy individuals with highest values in MR. Strain irrespective of layer assessed was associated with LV wall stress but seemed less related to contractility and unrelated to stroke work in the setting of normal LVEF.