gradient between the LA and LV, rather than actual flow. Furthermore, this parameter is highly dependent on loading conditions, heart rate and rhythm, atrial contractile function, and age, thereby limiting its ability to accurately describe diastolic function. Despite these limitations, because transmitral Doppler flow is easy to acquire and well described, characterization of these waveforms remains the basis for categorizing patterns of diastolic function.
transmitral doppler profiles
Figure 4 shows a normal transmitral flow pattern. There are two major components of normal transmitral flow: the rapid early filling phase, designated the E-wave, and filling associated with atrial contraction, designated the A-wave. Normal transmitral flow is characterized by an E:A ratio slightly greater than one and relatively brisk (150-220 ms) E-wave deceleration, defined as the time from the peak of the E-wave to the end of early mitral flow. The atrial contribution to ventricular filling typically does not exceed 20%.
annulus, between the body of the leaflets or apical to the leaflet tips have lower peak E-velocities. E-wave deceleration time is lengthened when the sample volume is too apically placed and shortened when the sample volume is too close to the mitral annulus.
2. Orient the image such that the transducer beam is parallel to flow (color flow Doppler may be used to optimize beam placement).
3. Sample volume size should be 1-2 mm; pulse wave Doppler should be used.
4. The velocity scale should be adjusted according to the peak velocity recorded (normal range of 60-130 cm/s); velocity filters should be minimized to record middiastolic flow and eliminate wall motion artifacts, sweep speed 50-100 mm/s.
5. Record several cardiac cycles during breath holding at the end of expiration.
General classification of diastolic function is based predominantly on the pattern of mitral inflow as determined by the relative heights of the E- and A-waves (E:A ratio), their peak velocities, and the rate of deceleration of the E-wave. Acceleration of flow across the MV (reflected predominantly in peak E-wave velocity) is influenced primarily by the transmitral pressure gradient. This pressure gradient is directly related to LA pressure and inversely related to ventricular relaxation (as LA pressure rises, or LV relaxation declines, peak
Normal flow is directed toward the mid- to distal posterolateral wall (approx 20° lateral to the apex); this lateral direction becomes more exaggerated with LV dilation (see Fig. 5).
1. Position the sample volume at the tips of the leaflets. Recordings obtained from the mitral
Was this article helpful?