Introduction
Mitral stenosis (MS) is a cardiac disorder generally caused by Rheumatic
Fever (RF) and characterized by morphological changes in the mitral
valve such as commissural fusion, retraction, thickening and narrowing
of the mitral valve apparatus and leaflets 1. Right
Ventricular (RV) failure has a critical role in the onset and
progression of clinical symptoms and the prognosis of MS patients, but
the exact role, effect, and pathophysiology of RV dysfunction in MS is
still controversial 2.. Some theories suggest that the
pathophysiological and structural changes that are caused by MS lead to
pulmonary hypertension (PH) and increased pulmonary artery pressure
(PAP), which eventually result in RV dysfunction 3. It
is still not known whether the degree of MS severity has a correlation
with RV dysfunction independent of PH and high PAP.
Furthermore, echocardiographic markers are able to predict
rehospitalization rates in MS patients4. Since a
delayed diagnosis can result in high rates of morbidity and mortality,
while early interventions have immensely improved clinical outcomes,
early detection of RV dysfunction is critical for the patients5. Various imaging methods have been employed to
evaluate RV function such as radionuclide angiography, contrast right
ventriculography, and novel modalities like magnetic resonance imaging;
however, most are confined by restrictions 6. Although
cardiac imaging has remarkably improved in recent years, measuring the
size and function of RV has remained a complex process due to the
special crescent structure of the RV and morphological differences
between the Left Ventricle (LV) and RV 7-9. Tissue
Doppler imaging (TDI) is a simple, safe, cost-effective, and accurate
modality for detecting both RV and LV dysfunction 10.
Even though TDI enhanced the diagnostic yield of echocardiography, the
reliability of its data is controversial due to its angle dependency11. Velocity Vector Imaging (VVI) is among the more
novel and more reliable means of investigating LV and RV function using
strain imaging, due to being angle-independent 12-16.
In order to assess the correlation of the degree of MS severity with RV
dysfunction and to discover the echocardiographic markers that can be
used as early diagnostic features of subclinical RV dysfunction, we
aimed to investigate the echocardiographic signs of systolic RV
dysfunction using TDI and VVI in patients with severe and very severe
mitral stenosis.