Pulmonary Regurgitation: Severity Criteria on EchoCG
Position and Study Modes
For the assessment of pulmonary regurgitation in educational guidelines (Blagodir, 2024), the parasternal short-axis view at the level of the RVOT (LAX RVOT) is used. The sequence of actions:
1. Obtain an image in CFD mode — assess flow in the RVOT, PV, PA, and bifurcation of the PA. Pulmonary stenosis, pulmonary regurgitation, and patent ductus arteriosus (PDA) are excluded.
2. Obtain a PWD/CWD flow spectrogram through the pulmonary valve (PV). Normally, the velocity is 0.6–0.9 m/s. The direction and velocity of the flow are evaluated. Increased velocity may indicate pulmonary stenosis.
Signs of Pathological Flow
Pathological flow appears as turbulent (chaotic, disorganized) or eccentric and is observed in valvular stenosis, valvular insufficiency, and septal defects. Regurgitation is defined as pathological flow in the opposite direction through a presumably closed valve — in this case, the pulmonary valve (PR).
Interpretation of Severity
According to fragments (Blagodir, 2024), moderate pulmonary regurgitation is a variant of normal. Exact quantitative thresholds for grading PR as mild/moderate/severe are not provided in the fragments [clarify].
Additional Measurements
If necessary, the end-diastolic pulmonary regurgitation velocity (EDPR) is measured and the EDPR gradient is calculated.
| Parameter | Value | Clinical Application |
|---|---|---|
| Flow velocity through PV (normal) | 0.6–0.9 m/s | Assessment of PV; increased velocity — suspicion of stenosis |
| EDPR gradient (normal) | 0–5 mmHg | Helps establish pulmonary artery pressure in heart failure |
Special Groups
For operated patients with tetralogy of Fallot, additional Doppler methods for quantitative assessment of PR are proposed in the literature: the simplified method by Festa et al. (2010) and the diastolic to systolic time-velocity integral ratio (Bhat et al., 2017); detailed threshold values of these methods are not provided in the fragments [clarify].
Frequently asked questions
In which position should pulmonary regurgitation be assessed?
In the LAX RVOT position: CFD flow in the RVOT, PV, PA, and bifurcation of the PA, plus PWD/CWD spectrogram through PV (Blagodir, 2024).
Is moderate PR a pathology?
According to fragments (Blagodir, 2024), moderate pulmonary regurgitation is a variant of normal.
What is the normal flow velocity through the pulmonary valve?
Normally, the flow velocity through PV is 0.6–0.9 m/s; an increase may indicate pulmonary stenosis.
Why measure the EDPR gradient?
The EDPR gradient (normal 0–5 mmHg) helps establish pulmonary artery pressure in heart failure.
Are there quantitative thresholds for PR severity in the sources?
Specific quantitative criteria for grading PR severity are not provided in the fragments [clarify]; refer to EAE/ASE guidelines (Lancellotti et al., 2010; Zoghbi et al.).