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Figure 1 Examples of transesophageal Doppler coronary flow recording in two different patients with stenosis of the proximal part of the LAD. A, Example of a patient with a moderate stenosis of the proximal part of the LAD. Left panel, Color Doppler flow mapping; note the changes in the color flow map, with blue indicating low velocities in front of the stenosis and a typical localized color aliasing at the site of the stenosis. Right upper panel, Pulsed Doppler recording upstream from the zone of color aliasing (prestenotic area); the peak diastolic velocity is 49 cm/s and the diastolic TVI is 25 cm. Right lower panel, High pulse repetition frequency Doppler recording of velocities at the site of color aliasing (stenotic area); velocities are significantly increased, with a peak diastolic velocity of 182 cm/s and a TVI of 64 cm. B, Example of a patient with a critical stenosis of the proximal part of the LAD. In this patient, only the diastolic velocity wave tracing can be well delineated. Upper panel, Pulsed Doppler recording in the prestenotic area; the peak diastolic velocity is 26 cm/s and the diastolic TVI is 12 cm. Lower panel, High pulse repetition frequency Doppler echocardiography allows the recording of velocities at the site of the stenotic area as high as 4 m/s, with a TVI of 198 cm. S = systolic wave; D = diastolic wave.
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