ABSTRACT
In mitral stenosis (MS), the inherent pathology is obstruction to inflow of blood into the Left ventricle (LV) from the left atrium (LA). As such, it has been believed that the LV systolic function should be normal as the pathology is upstream to LV. A number of studies have documented the presence of LV systolic dysfunction (usually defined as a LV ejection fraction of <50%). The importance of these findings relates primarily to the outcomes of relief of the mechanical obstruction (either by surgery or percutaneously). If the LV systolic dysfunction is indeed related to an inherent myocardial pathology, then the mere relief of valve obstruction may not lead to complete relief of symptoms. On the other hand, if the LV systolic dysfunction is related primarily to hemodynamic abnormalities, then the relief of MS should reverse the LV dysfunction. Thus, the debate, regarding the presence and causality of LV systolic dysfunction is more than a matter of semantics. The prevalence of LV systolic dysfunction in MS has varied with some studies performed a few decades quoting figures as high as 31%. These studies relied primarily on angiography and two-dimensional echocardiography. With the advent of strain echocardiography, subclinical LV systolic dysfunction has been reported in most patients (85%) despite normal LV ejection fraction (LVEF).
