Introduction
Mitral valve prolapse is a diagnosis that should be made clinically based on careful dynamic auscultation. While an echocardiogram is not necessary for the diagnosis, it is indicated to evaluate severity and associated lesions.

In our patient, an echocardiogram was performed to evaluate several issues: which leaflet(s) are prolapsing; the thickness of the leaflet(s); the degree of mitral regurgitation; the left ventricular and left atrial cavity sizes; left ventricular function and estimate of left atrial and pulmonary artery pressures. It is also helpful in detecting associated lesions such as a dilated aortic root in patients with Marfan's syndrome and prolapse of other valves. The complications of mitral valve prolapse occur predominantly in those with thickened leaflets.

Our patient's 2-D
This is a systolic still-frame of a two-dimensional echocardiogram in the parasternal long axis view in our patient. Note the structure identified by the arrow. The real-time study follows.
Choose the best description of the structure in the echocardiogram: