Cardiovascular Imaging

Flail mitral leaflet

rupture of the supporting apparatus of the mitral valve allowing the tip of the leaflet to project into the left atrium in systole. It results from rupture of multiple chordae or rupture of a papillary muscle. The most frequent aetiologies are chordal rupture complicating mitral valve prolapse syndrome or due to infective endocarditis, and papillary rupture caused by acute myocardial infarction. Primary degeneration of the chordae is a cause of spontaneous rupture. Typically, sudden onset of severe mitral regurgitation causes pulmonary oedema.

Plain radiography demonstrates pulmonary oedema with little or no cardiac or left atrial enlargement. Partial chordal rupture may result in more moderate chronic mitral regurgitation resulting in cardiomegaly with left atrial and left ventricular enlargement. Left ventriculography displays the tip of one of the leaflets flailing into the left atrium in systole and severe mitral regurgitation. Echocardiography, especially transoesophageal, is optimal for demonstrating the erratic motion of the flail leaflet and may disclose aetiological features such as infective vegetations.

CBH