The peak velocity of the tricuspid regurgitant jet gives the pressure difference between the RV and the right atrium. Add an estimate of right atrial pressure and you have RV systolic pressure, which equals pulmonary artery systolic pressure in most patients.
By James Napolitano. Cutoffs from the guidelines cited below.
Find the jet
Start in an RV-focused apical 4-chamber view.
Turn on color and find the TR jet in the right atrium during systole. It shows as a mosaic of colors.
Run the CW cursor through the tricuspid valve, parallel to the jet.
Check other views that line up with the jet, such as RV inflow, parasternal short axis or subcostal. Use the highest good-quality signal.
Live exampleFigure 1. Live RV-focused apical 4-chamber view with a CW cursor. The cursor starts off the jet, clips its edge, then lines up with it. CW records the fastest flow along the whole line, so missing the jet reads low. Drag the cursor yourself.
Measure the peak
Adjust the scale and baseline so the whole envelope is on screen. Measure the peak of the dense envelope, not the faint feathering beyond it. Every 10° off the jet underestimates the velocity, and squaring it in 4V² makes the pressure error larger.
Live exampleFigure 2. Live CW Doppler through the TR jet. Measure the peak of the dense envelope.
Tap a trace to freeze and measure.
Stroke volume
Apical 5-chamber
Angle to flow --
What the gate records
Move the gate and watch the trace change.
Calculate RVSP
RVSP = 4 × (peak TR velocity)² + RAP
IVC
Sniff collapse
RAP
2.1 cm or less
50% or more
3 mmHg (0 to 5)
Over 2.1 cm
Less than 50%
15 mmHg (10 to 20)
Any other combination
8 mmHg (5 to 10)
Calculator
m/s
cm
%
What is abnormal
Peak TR velocity of 2.8 m/s or more is abnormal and raises the probability of pulmonary hypertension.1 RVSP equals pulmonary artery systolic pressure when there is no pulmonic stenosis or RV outflow obstruction.1,2
Pitfalls
IVC-based RAP estimates do not apply during positive pressure ventilation.2
With severe, wide-open TR the jet can be laminar and triangular, and 4V² underestimates the gradient.
A faint or incomplete envelope reads low. Find a better window before trusting it.
Average the peak over the respiratory cycle.
Practice this on live Doppler.Critical Care Echo Trainer has all five measurements: stroke volume, RVSP, diastolic function, tamponade and TAPSE. Random cases with an answer key, and the full Acquire view with probe position and technique for each. $59, one-time.
Mukherjee M, Rudski LG, Addetia K, et al. Guidelines for the echocardiographic assessment of the right heart in adults and special considerations in pulmonary hypertension: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2025;38(3):141-186.
Rudski LG, et al. Guidelines for the echocardiographic assessment of the right heart in adults. J Am Soc Echocardiogr. 2010;23(7):685-713.