Doppler echocardiography adds a dynamic dimension to imaging the heart. The various forms of Doppler (PW, CW, and color) provide information on the velocity of flow in a selected area or along a beam path. Correlating the timing of the ECG and physiologic events allows for determination of flow direction (relative to the transducer) and the determination of flow normalcy. Transducer positions and sampling locations determine the display direction on the zero baseline. This results in a change in the display determined by the data collection method for the same flow.
The most important component of imaging the flow within the heart structures is the angle of incidence between the beam and transducer. Parallel flow creates the best Doppler signal resulting in an accurate depiction of normal or abnormal flow patterns. This underscores the importance of understanding the relationship of the sampled flow to the transducer position.
The technologist that understands the complexity of obtaining a quality Doppler signal has the basic skills needed to obtain a quality echocardiographic examination.
