DISCUSSION
Here we describe the differences in echocardiographic values together with the LV-GS, LA-GS and LA-RS profiles in different ventricular geometric variants. Furthermore, we assessed the factors associated with left ventricular and atrial dysfunction and found that they were previous myocardial infarction and eccentric hypertrophy. We found that those subjects with eccentric hypertrophy had up to 3.4-fold higher probability of LV-dysfunction and a 2.3-fold higher probability of having LA-dysfunction after adjusting for the previously mentioned associated risk factors. Further examination of the left atrium showed that the group with eccentric hypertrophy had the highest LA-volume and the lowest contraction phase.
The utility of global strain assessed by speckle tracking by echocardiography has been previously explored in several conditions including atrial fibrillation, cardiac myopathy, arrhythmia, heart failure, and overall cardiovascular outcomes in subjects with left bundle branch block (9,11,14,15). Overall, its clinical utility in cardiology has been attributed to its high reproducibility and its capacity for detecting structural and functional abnormalities compared with other imaging methods and without requiring extensive echocardiographic training (16). Furthermore, including subjects with previous myocardial infarction does not introduce bias into the use of global strain in functional analysis. This could be a noteworthy advantage since the evidence suggests that global strain is a reliable predictor of myocardial function and has good correlation in subjects with previously diagnosed myocardial infarction (16). Our results support the idea that strain is an excellent automatized method for evaluating structural myocardial changes in subjects with LVH.
The link between ventricular geometry, especially LVH and strain has been previously reported. Soufi Taleb Bendiab, et al. evaluated the association of ventricular geometry with LV-GS in 200 subjects with high blood pressure and found that reduced LV-GS was correlated with long-lasting, uncontrolled blood pressure and metabolic changes which were more pronounced in those with eccentric and concentric hypertrophy (17). Another study by Hare, et al. evaluated global longitudinal strain (GLS) in subjects with left ventricular hypertrophy for hypertensive heart disease and found that GLS values were decreased in subjects with concentric remodeling and concentric hypertrophy (18). Mizuguchi Y, et al. assessed the deterioration of systolic left ventricular myocardial deformation by two-dimensional strain echocardiography as early evidence of isolated diastolic heart failure in patients with hypertension and LVH in 98 patients and 22 age-matched normal controls, and they found that concentric LVH caused impairment of longitudinal, circumferential and radial myocardial deformation in patients with hypertension. Circumferential shortening was the major compensatory mechanism for maintaining LV pump function (19).
Our results suggest that the GLS measurements could be a complementary tool in the assessment of left ventricular function, independent of the ventricular geometry. Furthermore, its automated methodology could be performed by any medical personnel.
Our study also found that cardiovascular risk factors could be explored to identify subjects at risk for decreased myocardial function. This was previously reported by our group, in which T2D, arterial hypertension and dyslipidemia were frequent conditions among subjects who were referred to the NCD. The fact that these conditions were associated with myocardial dysfunction may suggest that our population has increased risk factors for cardiovascular events that predispose to develop structural changes which lead to a higher incidence of adverse outcomes and other cardiac complications (20).