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

1. Mukherjee M, et al. ASE right-heart and PH guideline. JASE. 2025;38:141–186.
2. Humbert M, et al. 2022 ESC/ERS PH guideline. Eur Heart J. 2022;43:3618–3731.
3. Augustine DX, et al. BSE PH protocol. Echo Res Pract. 2018;5:G11–G24.
4. 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.