Clinical presentation, diagnosis and management of acute mitral regurgitation following acute myocardial infarction

Acute mitral regurgitation (MR) is a frequent complication of acute myocardial infarction, with a variable presentation depending on the severity of MR and the integrity of the subvalvular apparatus. While most cases are asymptomatic or have mild dyspnea, rupture of chordae tendinea or papillary muscles are catastrophic complications that may rapidly lead to cardiogenic shock and death. Despite the presence of pulmonary edema and/or cardiogrenic shock, the murmur of acute MR is usually subtle due to rapid equalization of left atrial and left ventricular pressure gradient, and therefore misleading. Echocardiography is the definite diagnostic modality, allowing quantification of the severity of MR and the structural abnormalities within the subvalvular apparatus. Severe MR accompanied by rupture of chordae or papillary muscles should be managed with temporary stabilization with medical treatment or with mechanical circulatory support, with subsequent surgical intervention to repair or replace the valve.