Detection and localization of early diastolic forces within the left ventricle from inflow jet dynamics. A comparison between normal subjects and patients with dilated cardiomyopathy.

We studied the properties of the jet of blood entering the left ventricle from the left atrium during early diastole in 32 patients with dilated cardiomyopathy, and 24 normal subjects of similar age. The diameter of the jet was measured from the cross-sectional color Doppler image and its cross-sectional area (JA) was derived. Pulsed Doppler records of flow velocity were made at 1-cm intervals into the ventricle from the mitral ring. Peak (Vp) and mean (Vm) E wave velocity and time velocity integral (TVI) were determined. At any level in the ventricle, therefore, the early diastolic volume of blood remaining in the jet, i.e., the flow time integral, is given by JA.TVI; the local flow rate, Q, by JA.Vm; and jet momentum along the long axis of the ventricle by Q.Vp. In normals, the jet cross-sectional area fell from 5.9 (1.3) cm2 at the mitral ring to 4.9 (0.7) cm2 at 4 cm (P < 0.05), but the flow time integral fell proportionately more, from 46.0 (15.2) ml at the ring level to 15.9 (3.4) ml at 4 cm (P < 0.01). Axial momentum flux was 44 (13) x 10(2) cm4s-2 at the ring level, falling to 28 (10) x 10(2) cm4s-2 at 4 cm (P < 0.01). In dilated cardiomyopathy, the jet cross-sectional area was much smaller than normal, 1.9 (0.8) cm2 at the ring level, and it remained effectively constant, being 2.0 (0.9) cm2 at 6 cm (P < 0.01 vs normals).(ABSTRACT TRUNCATED AT 250 WORDS)