Bileaflet Mitral Valve Prolapse and Mitral Regurgitation
History: A 55 year-old male referred for evaluation of mitral regurgitation, which was thought to be moderate-to-severe on echocardiography.
Technique: The video shows ECG-gated SSFP images. The top row consists of a series of parallel slices that include a 3-chamber view. The bottom row consists of 3 parallel slices that include a 2 chamber view, and a single 4-chamber view. Short axis SSFP images (not shown) were obtained to determine the LV stroke volume. Phase contrast images through the great vessels (not shown) were obtained to assess the severity of regurgitation.
Findings: This case nicely demonstrates bileaflet mitral valve prolapse. The doming of both the anterior and the posterior leaflets during systole is readily appreciated in the 3 chamber view (red arrows). Both leaflets are thickened. Multiple dynamic jets of mitral regurgitation are clearly visible, as well (yellow arrow).
The stroke volume (100 ml) was determined from the short axis cine images as the difference between the end diastolic and end systolic volumes. The forward flow (88 ml) was determined from the phase contrast images through the aorta. The regurgitant volume is determined as the difference between the LV stroke volume and the forward flow, which in this case is: 100 ml – 88 ml = 12 ml.
Comment: Mitral valve prolapse (MVP) is the most common congenital valvular heart disease in adults with an estimated prevalence of ~5% in the United States. Its prognosis is usually benign. However, it can be associated with complications, including mitral regurgitation, subacute bacterial endocarditis, arrhythmias, and sudden death.
Mitral valve prolapse is classically described as the systolic anterior displacement of an abnormally thickened, redundant mitral valve leaflet into the left atrium during systole. On ausculation, patients with mitral valve prolapse often have mid systolic clicks and late systolic murmurs. The diagnosis should be made on both the physical examination (auscultation) and the echocardiographic findings. The key echocardiographic finding to support a specific diagnosis of MVP is superior systolic displacement of one or both of the valve leaflets >2 mm beyond the mitral valve annulus, as observed in the parasternal long axis (3 chamber) view. Other suggestive echocardiographic findings include leaflet thickening, redundancy, annular dilatation, and chordal elongation. In classic mitral valve prolapse, the maximum leaflet thickness is > 5 mm on echocardiography. The figure below shows the echocardiographic appearance of mitral valve prolapse.