Left Ventricular Function in Patients with Rheumatic Mitral Stenosis

The most common pathophysiologic cause of Mitral Stenosis (MS) is rheumatic disease [1]. Generally Left Ventricular (LV) systolic function is well preserved in isolated MS. LV chamber typically is normal or small. However, coexisting Mitral Regurgitation (MR), aortic valve disease, ischaemic heart disease, systemic hypertension, cardiomyopathy all may be responsible for elevation of Left Ventricular End Diastolic Pressure (LVEDP) [2]. Left Ventricular (LV) dysfunction has been described in pure Mitral Stenosis (MS), which may be a due to change in interaction between right and left ventricles, myocardial fibrosis or a chronic decrease in preload [3]. Even with normal ejection fraction (indicating preserved global left ventricular function), there can be impairment in long-axis function (measured by tissue Doppler echocardiography) [4]. Altered LV long-axis movement has been shown to be a sensitive indicator of early myocardial dysfunction. Atrial fibrillation has shown to cause impairment of LV function. Pulsed-wave Doppler tissue velocities have been proven to be a good tool for assessment of long-axis ventricular shortening and lengthening. In the echocardiographical assessment of LV function, the Ejection Fraction (EF), Tissue Doppler Imaging (TDI), Doppler strain, and 2D strain have been widely used [5]. EF is the most widely used index of contractile function, but due to the visual component, assessment of endocardial excursion is subjective and has high inter-observer variability [6]. TDI and Doppler strain are characterized by limitations of angle dependence, limited spatial resolution and deformation analysis in one dimension [7]. 2D strain is a novel technique which evaluates LV systolic functions more objectively and quantitatively, and does not have the limitations seen in EF, TDI, and Doppler strain; thus, it has become more commonly used in recent years [8]. In the diagnosis of LV dysfunction due to MS, some studies have shown EF, TDI, and Doppler strain to be useful however there is paucity of data. There are also very few studies combining both conventional and 2D strain echo for evaluation of LV systolic function after successful Percutaneous Balloon Mitral Valvotomy (PBMV). There are also lack of evidences comparing LV systolic function before and after the above-mentioned procedure in patients with severe rheumatic MS.