The right ventricle is geometrically complex, load sensitive, and difficult to summarize with a single measurement. A high-quality RV assessment combines focused acquisition, chamber dimensions, longitudinal function, area-based function, regional motion, haemodynamics, and clinical context.
Begin with the RV-focused apical view
The standard apical four-chamber view is optimized for the LV and may not display the maximal RV dimension. For an RV-focused view, reposition or rotate the transducer to maximize the RV basal diameter while keeping the LV apex and tricuspid annulus visible.
- Avoid shortening the RV long axis.
- Do not overrotate until the RV appears artificially large.
- Document the window so serial studies can reproduce it.
- Acquire the image at end-expiration when feasible and appropriate.
RV size measurements
Basal diameter
Measure the maximal transverse RV dimension in the basal one-third at end-diastole, approximately parallel to the tricuspid annulus.
Mid-cavity diameter
Measure the transverse dimension at the level of the LV papillary muscles, perpendicular to the RV long axis.
Longitudinal dimension
Measure from the plane of the tricuspid annulus to the RV apex. Confirm that the apex is not foreshortened.
Linear dimensions are useful but do not capture the full crescent-shaped chamber. Integrate them with RV area, regional shape, and other views.
TAPSE
Tricuspid annular plane systolic excursion measures longitudinal displacement of the lateral tricuspid annulus from end-diastole to peak systole.
Acquisition
- Obtain an RV-focused apical view.
- Place the M-mode cursor through the lateral tricuspid annulus.
- Align the cursor with the direction of annular motion.
- Measure total systolic excursion.
A value below approximately 1.7 cm is commonly considered abnormal, but the current laboratory guideline should be used.
Limitations
- Angle dependence can underestimate excursion.
- It reflects one basal longitudinal segment.
- It is load dependent.
- Postoperative pericardial constraint can reduce annular motion despite preserved overall RV output.
- Severe TR may produce large annular excursion despite impaired myocardial function.
Tricuspid annular S′
S′ is the peak systolic tissue-Doppler velocity at the lateral tricuspid annulus. A focused view and correct sample placement are essential.
Technique
- Use pulsed-wave tissue Doppler.
- Place the sample volume at the lateral annulus.
- Align the Doppler beam with longitudinal motion.
- Use an appropriate velocity scale and sweep speed.
- Avoid sampling the RV free wall too apically.
A value below approximately 9.5 cm/s is commonly considered abnormal. Like TAPSE, S′ represents basal longitudinal motion and is angle and load dependent.
Fractional area change
Trace the RV endocardial border in an RV-focused apical view at end-diastole and end-systole. Include trabeculations within the cavity area by tracing the compacted myocardium.
A value below approximately 35% is commonly considered abnormal.
Strengths
- Includes longitudinal and radial area change.
- Assesses more of the chamber than one annular measurement.
- Can identify discordance with TAPSE or S′.
Limitations
- Dependent on complete endocardial visualization.
- Does not include the RV outflow tract in the apical area.
- Foreshortening and border uncertainty affect both ED and ES areas.
- Irregular rhythm complicates frame selection.
Visual assessment still matters
Assess free-wall thickening, regional akinesis or dyskinesis, septal motion, RV shape, and the relationship between RV and LV size. Visual assessment should support—not replace—quantitative measurements.
When the parameters disagree
| Pattern | Possible explanation |
|---|---|
| Low TAPSE, preserved FAC | Postoperative state, angle error, reduced longitudinal motion with preserved radial function |
| Preserved TAPSE, low FAC | Regional dysfunction, severe TR, basal hypermobility, poor FAC tracing |
| Low S′ with normal TAPSE | Doppler misalignment, sample-position error, beat variation |
| All reduced | Global RV systolic dysfunction is more likely, but loading and image quality still matter |
Additional parameters
Depending on indication and laboratory protocol, integrate RV free-wall strain, 3D RVEF, RIMP, pulmonary artery acceleration time, TR velocity, estimated right-atrial pressure, pulmonary pressures, and RV–PA coupling indices.
The 2025 ASE right-heart guidance emphasizes comprehensive assessment and special considerations in pulmonary hypertension. Use the most current laboratory implementation rather than relying on an isolated historical cutoff.
Right atrium and IVC
RV function is interpreted with right-atrial size and pressure context. Measure RA area or volume at maximal atrial size. Assess IVC diameter and inspiratory response in the appropriate subcostal view, recognizing limitations in mechanically ventilated patients, athletes, and altered respiratory effort.
Quality-control checklist
- RV-focused view saved.
- Basal, mid, and longitudinal dimensions measured at end-diastole.
- TAPSE cursor aligned with annular motion.
- S′ sample positioned at the lateral annulus.
- FAC borders traced at true ED and ES.
- Regional motion, septal shape, and TR severity assessed.
- Discordant parameters explained rather than ignored.
Knowledge check
1. Why should RV dimensions not be measured from any apical four-chamber view?
Answer: RV size is highly view dependent; an RV-focused view is required to maximize and standardize the chamber.
2. Why can TAPSE be reduced after cardiac surgery without severe global RV failure?
Answer: Pericardial disruption and altered longitudinal mechanics can reduce annular excursion while other components of RV function are preserved.
3. What does FAC add to TAPSE?
Answer: FAC incorporates area change across more of the RV and includes radial as well as longitudinal contribution.