Why is continuous-wave Doppler preferred for assessing regurgitant jets?

Continuous-wave Doppler is preferred for assessing regurgitant jets primarily because it can measure high-velocity flow. In cases of regurgitation, such as mitral or aortic regurgitation, the blood flow can reach very high velocities during diastole when the heart is filling or in the presence of significant backflow.

Continuous-wave Doppler uses two transducer crystals that allow for the measurement of velocity without being limited by the Nyquist limit, which applies to pulsed-wave Doppler. This means that while pulsed-wave Doppler can accurately measure flow velocities only up to a certain limit (typically around 2 m/s), continuous-wave Doppler can provide accurate measurements for much higher velocities, which is critical for evaluating the severity of regurgitant jets.

The ability to assess high-velocity flow enhances the clinician’s understanding of the hemodynamics involved in regurgitation, which is essential for diagnosing and managing conditions like valvular heart disease. Thus, the capacity to measure these high velocities accurately is the key reason why continuous-wave Doppler is utilized in these scenarios.