Mitral valve contour in short axis: a useful view in the diagnosis of mitral valve prolapse

The diagnosis of mitral valve prolapse still remains a challenging proposition in some patients, particularly when the superior and posterior displacement of the mitral valve leaflets across the plane of the mitral valve annulus into the left atrium during systole is questionable. Therefore, additional reliable and reproducible echocardiographic criteria to improve the accuracy of mitral valve prolapse diagnosis would be ideal. In this small study, we proposed to assess the relationship between the systolic and diastolic contour of the mitral valve, as seen from the short axis views of the left ventricle, and compared to the currently used standard parasternal long axis view criteria. The apical views and the M-mode of the mitral valve were also assessed. From a total of 70 transthoracic echocardiograms that were prospectively examined, 50 echocardiograms were included for analysis. Nine patients met criteria for mitral valve prolapse using the parasternal long axis views standard definition. However, in these patients the concordance using M-mode and apical view criteria was 56% and 33%, respectively. None of the patients met M-mode criteria for mitral valve prolapse if the parasternal long axis criteria was not present, however 5 patients showed apical view mitral valve prolapse without meeting parasternal long axis views criteria. Conversely, a 100% concordance was noted between the parasternal long axis criteria for mitral valve prolapse and the contour of the mitral valve as seen from the short axis views. In all 9 patients with mitral valve prolapse, using the parasternal long axis criteria, a prominent buckling of the mitral valve was noted from the short axis views. Moreover, none of the 41 patients without mitral valve prolapse showed buckling in the short axis views. Therefore, buckling of the mitral valve, as seen from the short axis views, appears to provide a confirmatory role in diagnosing mitral valve prolapse, particularly in questionable cases; improving the overall accuracy. These findings should be validated in a double blind prospective study.