Echocardiographic criteria of the diagnosis of mitral-semilunar valve continuity.

A prospective echocardiographic study of 39 healthy adults with no history of heart disease was conducted to investigate the relationship between the anterior mitral valve leaflet (AMVL) and the posterior aortic root (PAR). The difference between the echocardiographic depth of the AMVL and the depth of the PAR with respect to the chest wall (CW) echoes was measured from both the third and fourth intercostal spaces in both the supine and left lateral positions. The results indicate that there were no statistically significant differences between the two depths in three of four measuring position postures. However, the best correlation between the depth of the AMVL had the PAR was obtained in the fourth ICS supine position. The echocardiographic difference between the CS-PAR and the CW-AMVL was less than or equal to 8 mm. in 90 per cent and less than or equal to 10 mm. in 97 per cent of our subjects in the fourth ICS. In the third intercostal space in the left lateral position, however, there was a statistically significant (P less than 0.01) difference in the two dimensions. In an individual subject, in any of the four possible positions, however, there were differences of up to 14 mm. in the two depths. The AMVL was found to be echocardiographically continuous with the PAR in all cases. An understanding of the normal AMVL-PAR relationship is becoming increasingly important, especially in regard to the application of echocardiography to the diagnosis of congenital heart disease, such as tetralogy of Fallot, double-outlet right ventricle, and transportation of the great vessels and of mitral regurgitation.