Maximal blood flow velocities--haemodynamic data obtained noninvasively with CW Doppler.

With continuous wave (CW) Doppler the maximal velocity in intracardiac jets can be recorded and simultaneous imaging makes the localization of these jets easier and unambiguous. The image may indicate the angle to the velocity, but the Doppler signal should be used to obtain the smallest angle and the highest velocity. Corrections for an assumed angle should be avoided since this may cause overestimation. With the maximal velocity a pressure drop can be calculated across obstructions and between chambers in regurgitations and shunts. The combined anatomic and haemodynamic information obtained with simultaneous two-dimensional echo and CW Doppler provides a good noninvasive assessment of most congenital and valvular lesions, including prosthetic valves.