Ischemic mitral regurgitation: Mechanisms and echocardiographic classification

Abstract

Chronic ischemic mitral regurgitation (IMR) is a common complication of myocardial infarction and severely affects cardiovascular mortality and morbidity. Multiple pathophysiologic mechanisms, such as left ventricular (LV) remodeling and dysfunction, annular dilation/dysfunction, and mechanical dyssynchrony, are involved in generating IMR, each of them having different weight. However, the prerequisite to initially creating regurgitation is the presence of local or global LV remodeling that alters the geometrical relationship between the ventricle and valve apparatus. In the wide spectrum of patients with chronic IMR, the assessment of some echocardiographic parameters, such as tethering pattern, leaflet motion, origin and direction of the regurgitant jets, allows one to identify different specific subgroups of patients subjected to different therapeutic approaches. The aim of medical and/or surgical therapy is to ameliorate heart failure symptoms, and improve LV remodeling and function and the intermediate/long-term outcome. The targets of surgical MV repair involve annulus, leaflets, chordae and ventricles. The restricted annuloplasty is the most commonly adopted surgical procedure that improves heart failure symptoms but not survival when compared to medical therapy and is also subject to a high incidence of late failure (approximately 30%). There are some preoperative echocardiographic predictors of failure that include valve (degree of valve remodeling, jet characteristics), ventricular (degree of remodeling, diastolic dysfunction) and surgical factors.

Assessment of mitral apparatus in patients with acute inferoposterior myocardial infarction and ischaemic mitral regurgitation with two-dimensional echocardiography from anatomically correct imaging planes

“…The results of many studies demonstrate higher incidence of IMR in inferior compared with anterior MI. Inferior basal LV remodelling causes more severe geometric alterations in the mitral valve apparatus with greater displacement of PMPM [15][16][17][18][19]. Based on these findings, in this study mitral valve geometry was assessed in patients with inferoposterior MI.…”

Ischemic mitral insufficiency correction and its progression after coronary artery bypass grafting

“…-дилатация и/или дисфункция фиброзного кольца (ФК) МК; -дисфункция миокарда ЛЖ; -механическая диссинхрония ЛЖ [3]. Нарушение геометрии ЛЖ, развитие его дилатации и снижение сократительной функции миокарда ЛЖ являют-ся ведущими механизмами в патогенезе ИМР.…”

“…кардиология и сердечно-сосудистая хирургия, 3,2016 Ишемическую митральную регургитацию (ИМР) определяют как недостаточность митрального клапана (МК), которая сочетается с нарушением сократимости 1 сегмента и более левого желудочка (ЛЖ), наличием зна-чимого поражения коронарных артерий (КА), со струк-турно нормальными створками и хордальным аппаратом МК («патофизиологическая триада» по A. Carpentier) [12,13].…”

Significance of papillary muscle function of the mitral valve and adjacent left ventricular segments in the progression of ischemic mitral regurgitation in patients with coronary heart disease after surgical treatment

“…Дополнительными факторами, играющими роль в формировании степени ИМР, являются: дилатация и/или дисфункция фиброзного кольца МК; дисфункция мио-карда ЛЖ; механическая диссинхрония ЛЖ [1,2].…”