June Cheng-Baron1, Jessica M. Scott2,
Ben T. Esch2, Mark J. Haykowsky2, John V. Tyberg3,
Richard B. Thompson1
1Biomedical Engineering, University of
Alberta, Edmonton, AB, Canada; 2Physical Therapy, University of
Alberta, Edmonton, AB, Canada; 3Cardiac Sciences, University of
Calgary, Calgary, AB, Canada
It
has been shown that blood velocity waveforms measured at the conventional
mitral leaflet tips location do not match mitral flow waveforms. In this
study we quantify the relationship between velocity profiles at several
points along the inflow path and volumetric flow, illustrating the dependence
of commonly derived diastolic parameters (E/A ratio, deceleration time) on
the measurement approach. Velocity profiles and derived parameters vary significantly
over small (1 cm) intervals and are distinct from flow profiles.
Velocity-time curves above the conventional leaflet tip location (in the
atrium) are less susceptible to measurement error and are most similar to
flow curves.