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).