[Possibilities of stress-echocardiography in diagnostics of pathology of mitral valve. Part II].

The paper deals with different aspects of application of stress-echocardiography for assessment of mitral valve disease (acquired stenosis or insufficiency, mitral regurgitation due to ischemic heart disease and mitral valve prolapse). Continuity equation is preferable to pressure half-time and resistance for estimation of hemodynamic significance of mitral stenosis. In some patients studies at rest reveal only slight mitral regurgitation while during stress it becomes hemodynamically significant and associated with pronounced elevation of pulmonary artery pressure. Deterioration of left ventricular function in this pathology often occurs before appearance of symptoms and even before increase of left ventricular dimensions and lowering of ejection fraction can be registered by echocardiography at rest. In patients with mitral valve prolapse stress induced mitral regurgitation has high predictive power for unfavorable clinical course. It is necessary to remember that in this group of patients abnormalities of left ventricular function during stress can be found in the absence of ischemic heart disease or pronounced regurgitation.