Interobserver and intraobserver variation of cross sectional early mitral flow velocity profiles from color Doppler

Cross sectional velocity profiles from early mitral blood flow were constructed from the velocity data obtained from sequentially delayed two-dimensional digital Doppler ultrasound maps in ten normal subjects. The data suggested that the early mitral flow studied from an apical four chamber view was variably skewed between subjects. The maximum flow velocity overestimated the cross sectional mean velocity at the same time by a factor of 1.2 to 1.7. The maximum time velocity integral from early mitral inflow was 1.3 to 1.9 times higher than the cross sectional mean time velocity integral. Based on three sets of recordings made by two observers the inter- and intraobserver variation of both the analyzing and the recording procedures of the method were studied. The limits of agreement were within 27% defined as percent of the sample mean for the intraobserver comparisons and within 35% for the interobserver comparisons respectively. The obtained results indicate that the method is reliable. The presence of a variably skewed cross sectional flow velocity distribution of the early mitral flow should be kept in mind when flow velocity measurements are made from only a part of the flow area for the purpose of volume flow calculations.