DIAGNOSIS AND CLASSIFICATION OF THE MITRAL-VALVE PROLAPSE BY THE ULTRASOUND CARDIOTOMOGRAPHY AND THE EVALUATION OF THE M-MODE TECHNIQUE

Eighty cases with mitral valve prolpase excluding the secondary prolapse of the mitral valve caused by known underlying diseases were studied by real-time ultrasoundcardiotomography and M-mode technic. It was thought that observation of the left ventricle with long axis sector scan was useful and sensitive technic to diagnose the mitral valve prolapse. By comparative study of M-mode technic and ultrasoundcardiotomography, echo sources and the mechanism of so called prolapse patterns such as pansystolic bowing, mid-systolic buckling and multilayered echoes were explained. Pansystolic bowing and mid-systolic buckling were considered as the reliable signs for diagnosis of anterior leaflet prolapse, but were not contributory to diagnose posterior leaflet prolapse and ultrasoundcardiotomographic technic was needed to detect the posterior leaflet prolapse. According to the mode of prolapsing findings by ultrasoundcardiotomograms classification of severity of mitral valve prolapse was undertaken and its grade was expressed as AmPn in which A and P designated prolaspe of the anterior and posterior leaflet respectively and m and n indicated the grade of severity in number from zero to five. © 1979, The Japanese Circulation Society. All rights reserved.