Pulse wave Doppler echocardiography of the left ventricular outflow tract

The PW Doppler signal is obtained from the anteriorly angulated apical five chamber echocardiographic view (panel A). The arrow indicates the position of the sample volume in the LVOT. The PW Doppler signal from the LVOT is shown in panel B. By tracing the Doppler profile (blue dotted line), the VTI of the LV outflow can be obtained. The VTI reflects the distance that the column of blood travels through the LVOT during systole (also called stroke distance), and can be used to compute LV stroke volume by multiplying the LVOT VTI by the cross sectional area of the LVOT. Normal value for LVOT VTI is typically >18 cm.