Audience: cardiology trainees, sonographers and clinicians interpreting adult echocardiography.
Evidence reviewed: 19 September 2026.
Key message: echocardiography estimates the probability and consequences of pulmonary hypertension (PH). It does not establish PH from a single pulmonary artery systolic pressure cut-off. Right-heart catheterisation (RHC) remains the reference method when haemodynamic confirmation will affect management.
Learning objectives
- Acquire and interpret peak tricuspid-regurgitation velocity correctly.
- Combine TR velocity with supporting signs from the ventricles, pulmonary artery and IVC/right atrium.
- Estimate RV systolic pressure while recognising major sources of error.
- Report RV adaptation and likely aetiology, not pressure alone.
Start with the invasive definition
The 2022 ESC/ERS definition of PH is a resting mean pulmonary artery pressure above 20 mmHg measured at RHC. Classification additionally requires pulmonary arterial wedge pressure and pulmonary vascular resistance. An echo-derived PASP cannot replace these measurements.
1. Measure peak TR velocity
Use continuous-wave Doppler from multiple windows, including the RV-focused apical four-chamber, parasternal RV inflow, parasternal short-axis and subcostal views where useful. Record the highest complete, well-aligned envelope. Do not trace artefact, excessive spectral broadening, an incomplete envelope or a post-ectopic beat.
In sinus rhythm, use representative beats. In atrial fibrillation or marked beat-to-beat variation, average five to seven suitable beats acquired under comparable loading conditions. A weak or absent TR signal does not exclude PH.
2. Determine echocardiographic probability
The BSE probability algorithm uses peak TR velocity as its first branch. A peak velocity above 3.4 m/s supports high probability. A velocity at or below 2.8 m/s supports low probability only when additional PH signs are absent. Intermediate values require supporting evidence. The 2025 ASE guideline similarly emphasises an integrated approach rather than fixed PASP severity bands.
| Domain | Supporting findings |
|---|---|
| Ventricles | RV greater than LV at the basal level; septal flattening or LV eccentricity index above 1.1; RV hypertrophy, dilatation or systolic dysfunction |
| Pulmonary artery/RVOT | RVOT acceleration time at or below 105 ms; mid-systolic notching; early-diastolic PR velocity above 2.2 m/s; dilated pulmonary artery |
| IVC/right atrium | Right-atrial enlargement; IVC above 21 mm with reduced inspiratory collapse |
Use findings from more than one domain. No single adjunctive sign is diagnostic in isolation.
3. Estimate RV systolic pressure carefully
When there is no RVOT or pulmonary-valve obstruction:
RVSP = 4 × (peak TR velocity)² + estimated right-atrial pressure
If peak TR velocity is 3.0 m/s and estimated RAP is 15 mmHg, RVSP is 4 × 9 + 15 = 51 mmHg. Report this as an estimate. Do not label PH mild, moderate or severe from fixed PASP bands.
| IVC pattern | Suggested RAP |
|---|---|
| ≤21 mm and >50% inspiratory collapse | 3 mmHg |
| Discordant size and collapse | 8 mmHg |
| >21 mm and <50% inspiratory collapse | 15 mmHg |
RAP estimation is less reliable with positive-pressure ventilation, raised intra-abdominal pressure, pregnancy, athletic remodelling, severe TR and poor subcostal imaging.
Important pitfalls
- Underestimation: poor alignment, incomplete envelope, weak TR, advanced RV failure, severe free-flowing TR or early RV–RA pressure equalisation.
- Overestimation: tracing noise, excessive gain, spectral broadening, a post-ectopic beat or an incorrect RAP estimate.
- RVSP approximates PASP only when there is no obstruction between the RV and pulmonary artery.
- An ultrasound-enhancing agent may improve a weak envelope, but overgaining creates a falsely traceable signal.
Assess the RV and seek the cause
Report RV geometry, basal diameter, wall thickness where relevant, TAPSE, lateral S′, FAC, RV free-wall strain when available, RA size, TR mechanism/severity and pericardial effusion. Consider left-heart disease, valve disease, congenital shunt, lung disease/hypoxia, chronic thromboembolic disease, pulmonary arterial hypertension and mixed causes.
Suggested report
Peak TR velocity is 3.2 m/s. RV dilatation, systolic septal flattening and a dilated IVC with reduced inspiratory collapse indicate a high echocardiographic probability of pulmonary hypertension. RV systolic function is reduced by FAC and RV free-wall strain. Clinical correlation and specialist assessment are advised. Consider RHC if confirmation and haemodynamic classification will alter management.
References
- Mukherjee M, et al. ASE right-heart and PH guideline. JASE. 2025;38:141–186.
- Humbert M, et al. 2022 ESC/ERS PH guideline. Eur Heart J. 2022;43:3618–3731.
- Augustine DX, et al. BSE PH protocol. Echo Res Pract. 2018;5:G11–G24.
- Zaidi A, et al. BSE right-heart guideline. Echo Res Pract. 2020;7:G19–G41.
Educational content for clinicians. It does not replace patient-specific assessment, local protocols or specialist advice.
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