Mitral regurgitation

Case history

A 52-year-old woman presents with dyspnea on exertion, fatigue, and occasional palpitations. She has no prior cardiac history. She denies chest pain, orthopnea, paroxysmal nocturnal dyspnea, or lower extremity edema. On physical exam her jugular venous distension is around 12 cm and her lungs are clear to auscultation. Cardiac exam reveals a slightly displaced apical impulse with a palpable P2. Cardiac auscultation reveals III/VI holosystolic murmur at the apex that radiates to the axilla with diminished S1 and P2 greater than A2.

Other presentations

Acute MR is serious and rare. It may occur in the setting of acute myocardial infarction and leads to high left atrial pressure and pulmonary edema secondary to reduced left atrial compliance. It usually presents as a sudden and marked increase in congestive heart failure symptoms, with weakness, fatigue, dyspnea, and sometimes respiratory failure and shock. It is usually associated with peripheral vasoconstriction, pallor, and diaphoresis. Occasionally no murmur is heard, because the lack of left atrial compliance leads to equalization of pressures between the left atrium and ventricle midway through systole.

Chronic MR is associated with a laterally displaced apical impulse (with left ventricular dilation), diminished S1, with or without S3, with or without right ventricular heave, and palpable P2 (if pulmonary hypertension has developed).