Positioning of the transducer at the point of maximum impulse helps obtain an apical four-chamber view. A somewhat superior angulation of the transducer visualizes the aortic root in addition to both atria and ventricles. In this view, referred to as an apical five-chamber view, orient the ultrasound beam parallel to flow in the following areas: left atrium (LA), left ventricular inflow tract (LVIT), left ventricular outflow tract (LVOT), aorta (Ao), right atrium (RA), and right ventricular inflow tract (RVIT). Recording of diastolic flow, beginning after the T wave of the electrocardiogram, takes place in conjunction with sampling of the LA, LVIT, RA and RVIT. This flow occurs toward the apically positioned transducer and displays above the zero line.
When sampling the LVOT and Ao from this approach, blood flow begins after the R-wave of the electrocardiogram and displays below the zero line (away from the transducer). Flow both toward and away from the transducer may be recorded when sampling from an intermediate position in the left heart such that flow in both the left ventricular inflow tract and left ventricular outflow tract is observed.
