When mitral regurgitation is acute, the history may be quite different than when it presents in a chronic form. It is usually caused by a ruptured chordae tendineae, and the history may include infective endocarditis or trauma. In the setting of acute myocardial infarction, it is usually due to severe papillary muscle dysfunction or rupture. The sudden onset of left ventricular failure is typical.

In addition to the history, there are many bedside findings that differentiate acute from chronic mitral regurgitation. These findings may be observed in the arterial pulse, the jugular venous pulse, precordial movement, and on auscultation.

Most are related to the large volume overload entering a small, non-compliant left atrium, leading to pulmonary venous and pulmonary arterial hypertension.

Acute and chronic mitral regurgitation have been addressed as two distinct syndromes. In practice, there is a broad spectrum in the clinical presentation and many variations may be seen in an individual patient.