Chapter: The RV

RV Size RV Wall Thickness RV Function RA Pressure (E/e')

The Right Ventricle

An overview of right ventricular size and functional assessment

RIGHT VENTRICULAR SIZE

It is usually harder to evaluate RV size than LV size. The RV is usually first seen in the PLAX view when part of the outflow tract is seen. The normal shape in this view is a bit triangular. Measuring the “height” of the RV in this view is possible but not overly reliable and reference values are uncertain. The RV will also vary with patient height. However, for an average sized adult, a PLAX RV that is “rounder” and greater than 3.5 cm at end diastole indicates a possible problem. Here is a PLAX image with a clearly normal RV outflow height.

Next is a PLAX clip from a patient with verified RV dilation. The RV outflow height was about 4.0 cm at end diastole.

The apical view is the standard for measuring the RV width. Both leaflets of the tricuspid valve need to be seen for a correct view of the RV. Measuring just the mid RV diameter is good enough in most clinical situations. Next is a clip of a dilated RV, although a common problem of an uncertain lateral RV wall was demonstrated.

To be sure about the RV lateral wall an RV enhanced apical4 view may be needed. Here is a slightly RV-enhanced view that enabled a good measurement of the mid-RV diameter.

The RV free wall is usually measured in the subcostal view because we need the interface with the liver to make the wall clear. Here is an image from a patient with pulmonary hypertension who had hypertrophy of the free wall. A more precise measurement would have been obtained if the wall had been centered in the screen and then magnified.

RV dimensions (cm)

Normal

Mild

Mod

Severe

Mid RV

2.7 - 3.3

3.4 - 3.7

3.8 - 4.1

≥ 4.2

RV free wall

0.1 - 0.6

 

 

 


RIGHT VENTRICULAR FUNCTION

There is a separate chapter on the tricuspid valve that will deal with measurement of RV and pulmonary pressures.  An indicator of RV volume and pressure overload is flattening (D-ing) of the PSAX interventricular septum as an overloaded RV presses into the LV. This pattern may occur just during systole (usually pressure overload), throughout systole and diastole (usually volume and pressure overload), or briefly just with inspiration (classic cardiac tamponade pattern). The next clip shows PSAX septal flattening predominantly with systole and the flattening was accentuated during inspiration.

The following clip is an apical4 view from a patient with poor LV systolic function, but the increased RV pressure/volume shifted the septum into the LV with each beat.

RV function has a much greater component of longitudinal contraction than LV function and this is most easily measured with tricuspid annular plane systolic excursion (TAPSE). Adjust the image to get the lateral tricuspid annulus excursion roughly parallel to the M-mode cursor. This may require moving the annulus toward the center of the screen with an LV enhanced view. Next is a normal TAPSE tracing. As with MAPSE, find the peak and the valley and drop the caliper straight to the bottom and subtract to get the difference. In this case TAPSE was 2.6. Good TAPSE is usually easy to eyeball after enough training.

 

 

Normal

TAPSE (cm)

1.7 - 3.1

 

DOPPLER ANALYSIS OF THE RV

RV inflow and tricuspid annulus TDI analysis can be done as on the left heart. However, much less work has been done on this and it is more difficult to get good RV views and measurements at optimal end-inspiration. Accordingly, Doppler analysis of the RV can’t be standard for IMBUS.