Pulmonary artery signs of PH

AcT, notching, PR velocity, PA diameter · PW in the RVOT (PSAX); CW of PR; PA diameter at the bifurcation

Normal range & thresholds

ESC/ERS 2022 category-B signs ^[8]:

• RVOT acceleration time <105 ms and/or mid-systolic notching
• Early-diastolic PR velocity >2.2 m/s
• PA diameter >25 mm (or larger than the aortic root)

Pathophysiology

A stiff, high-resistance pulmonary circulation reflects the pressure wave back early, shortening acceleration and notching the envelope; PR velocity encodes the PA–RV diastolic gradient (≈ mean PAP); chronic pressure dilates the trunk ^[47,8].

Raised by

• PA dilatation: PH, PS post-stenotic, high-flow shunts, connective-tissue disease

Lowered by

• AcT shortens with tachycardia and low output (confounders)

Technique & pitfalls

• Sample volume at the pulmonary valve annulus in the RVOT; sweep 100 mm/s; heart rate 60–100.

Pseudo-change & artefact

• Tachycardia shortens AcT; poor PR envelopes; oblique PA measurement.

Treatment thresholds

• Two categories of signs upgrade the PH probability and prompt right-heart catheterisation when appropriate ^[8].

Next step

• PVR estimate (card 66); V/Q scan for CTEPH in unexplained PH ^[8].

Drugs

Pulmonary vasodilators in responders lengthen AcT.

Reversibility

Partly reversible with treatment.