RT Book, Section A1 Groarke, John D. A1 Carabello, Blase A. A1 O’Gara, Patrick T. A2 Fuster, Valentin A2 Harrington, Robert A. A2 Narula, Jagat A2 Eapen, Zubin J. SR Print(0) ID 1161731540 T1 ISCHEMIC MITRAL REGURGITATION T2 Hurst's The Heart, 14e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9780071843249 LK accesscardiology.mhmedical.com/content.aspx?aid=1161731540 RD 2024/10/09 AB Mitral regurgitation (MR) can be classified into two major etiologic categories: primary (degenerative) and secondary (functional). Primary MR is a consequence of disease affecting the leaflets or chordae tendineae, such as in mitral valve (MV) prolapse, myxomatous degeneration, infective endocarditis, or rheumatic disease. These disease processes are discussed in Chap. 48. In secondary MR, leaflet structure is normal and the valve is more of an “innocent bystander.” Regurgitation results from a distortion of the normal spatial and functional relationships of the left ventricle (LV) and valve apparatus, usually as a consequence of adverse LV remodeling. The trigger for LV remodeling can be ischemic (following myocardial infarction [MI]) or nonischemic (as with dilated cardiomyopathy) (Fig. 49–1). This chapter will focus on chronic ischemic MR (IMR) and will not discuss acute severe MR caused by papillary muscle rupture in the acute/subacute phase of MI.