Limitations
The major limitation of our study is that we included only isolated
severe MS patients and hence our results are not applicable to patients
with multi-valvular disease or other valve disease. This was done so as
to have a uniform study population as including subjects with
regurgitant lesions would have resulted in volume overload of the left
atrium thereby affecting the results. Secondly our results are not
applicable to patients in AF as they were excluded. This was because the
speckle tracking echocardiography is ideally for patients with regular
heart rhythms as strain values are directly influenced by the length of
diastole. Thirdly, image quality and different vendor machines as well
different versions of software of the same vendor may affect the
results. However, the same equipment and software were used to assess
all study subjects thereby avoiding any inconsistency in measurements.
Fourthly invasive cardiac catheterization was not done in our study.
This was because two-dimensional echocardiography is standard technique
to evaluate patients with rheumatic MS. Lastly we did not study the
effect of BMV on LA strain parameters which requires further
investigation.