Reduced early diastolic inflow velocities in the antero-posterior transverse direction in the left ventricle of patients with dilated cardiomyopathy

In patients with dilated cardiomyopathy (DCM), the left ventricular (LV) in flow jet is narrow and has a high pressure gradient. A pulsed Doppler restr ictive transmitral flow pattern is a characteristic feature of severe left ventricular disease. However, Doppler flow analysis is limited by the angle between the blood flow jet and the ultrasonic beam. In this study we used gated magnetic resonance imaging (MRI) to investigate the inflow velocity i n the LV transverse directions during early diastole in patients with DCM. Methods: We studied 10 patients with DCM (mean age: 47 y). Ten age-matched healthy volunteers were also examined. Gradient echo images of the LV were obtained. Left ventricular short axis phase contrast images were obtained a t the level of the mitral valve tip and 1 cm inside the LV. Long axis image s were also obtained. Through-plane peak velocities at peak early diastolic filling were measured along the LV long axis, antero-posterior short axis, and right-left short axis. Blood velocity was measured in 50 ms blocks. Re sults: Early diastolic inflow velocity along the long axis, especially at t he center of the LV, was well preserved in DCM. However, the inflow velocit y in the antero-posterior transverse direction of the LV (i.e., in the dire ction of mitral valve excursion) was significantly reduced in DCM. Conclusi ons: Early diastolic inflow velocity in the antero-posterior transverse dir ection of the LV is reduced in patients with DCM indicating that the vector component of the forces acting in the antero-posterior transverse directio n of the LV may be decreased in patients with DCM during early diastolic fi lling.