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

UNLABELLED: In patients with dilated cardiomyopathy (DCM), the left ventricular (LV) inflow jet is narrow and has a high pressure gradient. A pulsed Doppler restrictive 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 in 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 at the level of the mitral valve tip and 1 cm inside the LV. Long axis images 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.

RESULTS: Early diastolic inflow velocity along the long axis, especially at the center of the LV, was well preserved in DCM. However, the inflow velocity in the antero-posterior transverse direction of the LV (i.e., in the direction of mitral valve excursion) was significantly reduced in DCM.

CONCLUSIONS: Early diastolic inflow velocity in the antero-posterior transverse direction of the LV is reduced in patients with DCM indicating that the vector component of the forces acting in the antero-posterior transverse direction of the LV may be decreased in patients with DCM during early diastolic filling.