Although the prevalence of rheumatic fever is decreasing in developed countries, it still affects numerous areas in the non- industrialized world. Untreated mitral stenosis (MS) contributes significantly to global morbidity and mortality. Echocardiography is the main diagnostic imaging modality for evaluation of mitral valve (MV) obstruction and assessment of severity and hemodynamic consequences of MS as well as valve morphology. According to current guidelines and recommendations for clinical practice, the severity of MS should not be defined by a single value but assessed by valve areas, mean Doppler gradients, and pulmonary pressures. Transthoracic echocardiography is usually sufficient to grade MS severity and to define the morphology of the valve. Transesophageal echocardiography is used when the valve cannot be adequately assessed with transthoracic echocardiography and to exclude intracardiac thrombi before a percutaneous or surgical intervention. Three-dimensional transthoracic and transesophageal echocardiographic assessment provide more detailed physiological and morphological information. Current definitive treatment for severe MS involves percutaneous balloon mitral valvuloplasty (PMBV) or surgery. The effectiveness of PMBV is related to the etiology of MS, and certain anatomic characteristics tend to predict a more successful outcome for PMBV, whereas other MV structural findings might suggest balloon valvuloplasty to be less likely successful or even contraindicated. Does 3D echo can add more useful information over 2 D echo that could change treatment decision?

Inclusion Criteria:

1. Patient age range from 18 years to 60 years.
2. Patient with isolated mitral stenosis (except those with mild mitral regurgitation and are candidate for PTMC by 2D Echo evaluation).
3. Patient with normal left ventricular EF
4. patient both in sinus rhythm or atrial fibrillation

Exclusion Criteria:

1. Age below 18 years or above 60 years.
2. Patient with another valve lesion or more than mild mitral regurgitation.
3. Patient with impaired cardiac function.
4. Mitral stenosis of other etiology than rheumatic origin

will be taken as a total coverage over a period of 1 year from patients attending Assiut University Heart Hospital outpatient clinic.