First, because calci- fication involves the annulus and base of the leaf- lets without commissural fusion, there is no role CLINICAL STATEMENTS AND GUIDELINES for PMBC or surgical commissurotomy. Second, the presence of severe mitral annular calcification can be quite challenging for the surgeon because of technically difficult in securely attaching the prosthetic valve and placement of the prosthetic valve may result in narrowing of the orifice.17 22 Finally, patients with calcification are often elderly and debilitated, have multiple comorbidities, and are at high surgical risk.1 3 For these reasons, intervention should be delayed until symptoms are severely limiting and cannot be managed with diuresis and heart rate control. Catheter-based therapies for these high surgical risk patients are being developed and evaluated.23 7. MITRAL REGURGITATION 7.1. Acute MR Acute MR may be caused by disruption of different parts of the mitral valve apparatus. IE may cause leaflet perfo- ration or chordal rupture. Spontaneous chordal rupture may occur in patients with myxomatous mitral valve dis- ease. Rupture of the papillary muscle occurs in patients who have an acute ST-segment elevation myocardial infarction, usually associated with an inferior infarction. The acute volume overload on the LV and LA results in pulmonary congestion and low forward cardiac out- Diagnosis of the presence and etiology of acute MR, along with urgent intervention, may be lifesaving. 7.1.1. Diagnosis of Acute MR In patients with acute MR, TTE is the initial imaging mo- dality of choice to evaluate LV function, RV function, pulmonary artery pressure, and mechanism of MR. The patient with severe acute MR, which might occur from chordal rupture, usually experiences acute hemody- namic decompensation. 