Mitral regurgitation is defined as an abnormal reversal of blood flow from the LV to the left atrium. It is caused by disruption in any part of the mitral valve apparatus. Mitral regurgitation is independently associated with female sex, low body mass index, advanced age, renal dysfunction, prior myocardial infarction, prior mitral stenosis, and prior mitral valve prolapse.
Symptoms of mitral regurgitation may be subtle because its progression may be insidious and patients may self-limit their physical activity. When associated with coronary artery disease and acute myocardial infarction, significant acute mitral regurgitation is accompanied by symptoms of impaired LV function, such as dyspnea, fatigue, and orthopnea. In these cases, pulmonary edema is often the initial manifestation.
Chronic mitral regurgitation often results from a primary defect of the mitral valve apparatus, with subsequent progressive enlargement of the left atrium and ventricle. In this state, patients may remain asymptomatic for years. Patients may have normal exercise tolerance until systolic dysfunction of the LV develops, at which point they may experience symptoms of a reduced forward cardiac output. With time, patients may feel chest palpitations if atrial fibrillation develops as a result of chronic atrial dilatation.
Key considerations regarding diagnostic studies from the 2017 ACC expert consensus decision pathway on the management of mitral regurgitation include the following:
Exercise testing can be useful for assessment of functional status and symptomatic elicitation; exercise echocardiography may reveal elevated pulmonary artery pressures, mitral regurgitation worsening, or blunted LV or right ventricular contractile reserve.
Determine the mechanism and etiology of mitral regurgitation, usually with TTE, or, if the image quality is poor, with transesophageal echocardiography TEE. Assess the mitral apparatus, and obtain careful measurement of left atrial volume and LV diameter and volume.
Distinguish between primary mitral regurgitation and secondary mitral regurgitation.
After characterization of leaflet morphology, describe the leaflet motion using the Carpentier classification system.
Initial assessment of the mitral regurgitation severity should be done with color-flow Doppler ultrasonography. Additional testing, including TEE and cardiac MRI, should be used when the assessment of mitral regurgitation on TTE is not definitive.
According to the ACC guidelines, the principal intervention for primary mitral regurgitation is surgery; however, transcatheter mitral valve repair using an edge-to-edge clip plays a very limited role. Whenever feasible, mitral valve repair is strongly preferred over mitral valve replacement for primary mitral regurgitation.
Read more about mitral regurgitation.
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Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Yasmine S. Ali. Fast Five Quiz: Heart Valve Disease - Medscape - Apr 22, 2020.
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