A critical appraisal of M-mode echocardiography in mitral stenosis

The reliability of M-mode echocardiography in confirming mitral stenosis and in assessing its severity was tested in 39 patients with mitral stenosis. None of the conventional echocardiographic signs of mitral stenosis is absolutely reliable. Unless at least 2 signs are combined, the diagnosis is not conclusive (sensitivity = 0.97, specificity = 1.00). Of a number of echocardiographic parameters and equations recommended (as tools) to determine the severity of mitral stenosis, the early diastolic velocity of anterior leaflet opening (EF) is the only one with a statistically significant relationship to the mitral valve area (MVA) calculated by Gorlin (r = 0.712, p less than 0.001), and this only in uncomplicated unoperated mitral stenoses, but not in mitral restenoses and combined mitral defects. Even the recently published Seitz's equation for calculating MVA from echocardiographic data is not reliable. M-mode echocardiography is an excellent technique for the primary diagnosis of mitral stenosis. However, it is not suitable to even an approximate assessment of its haemodynamic severity.