Tricuspid Regurgitation: 5-Grade Severity Scale (mild–torrential)
Extended TR Severity Grading
In the ASE 2025 guidelines (Guidelines for the Standardization of Adult Echocardiography Reporting), the severity of tricuspid regurgitation is proposed to be described in five grades: mild, moderate, severe, massive, or torrential. This extended scale is also applied in tricuspid valve stress echocardiography, where at each stage of the protocol, the severity of TR, peak TR velocity, and corresponding systolic pulmonary artery pressure are assessed, describing the dynamics as 'no change' or 'increase'.
Exact quantitative thresholds for the massive and torrential categories are not detailed in the provided excerpts. [clarify]
Key Measurements in TR Assessment
The most important aspect is the careful measurement and documentation of the maximum tricuspid regurgitation velocity (TRVmax) and the assessment of the estimated systolic pulmonary artery pressure — this is critical for evaluating dyspnea, fatigue, diastolic function, and valvular pathology (ASE 2025).
| Parameter | Value | Source |
|---|---|---|
| TRVmax, upper limit of normal | <2.5 m/s | Blagodir, 2024 |
| Vena contracta (width) in severe TR | >0.7 cm | Manual of Echocardiography, 2024 |
| Normal transtricuspid flow velocity | 0.3–0.7 m/s | Blagodir, 2024 |
Calculation of Pulmonary Artery Pressure
In the absence of RV outflow tract obstruction, the right ventricular systolic pressure (RVSP) is assessed by TRVmax and right atrial pressure (RAP); RVSP corresponds to the systolic pulmonary artery pressure (RVSP = SPAP) (Blagodir, 2024).
Features of Functional TR
With multiple TR jets, assessing severity can be challenging. The mechanism of TR is described as incomplete leaflet coaptation, subvalvular apparatus pathology, or tricuspid annular dilation. In Ebstein's anomaly, TR is the most common functional valve abnormality and is typically low-pressure regurgitation; its severity is a significant prognostic factor (Manual of Echocardiography, 2024).
Frequently asked questions
How many TR severity grades does ASE 2025 recommend?
Five: mild, moderate, severe, massive, and torrential (ASE 2025).
What vena contracta width indicates severe TR?
A vena contracta width >0.7 cm indicates severe TR (Manual of Echocardiography, 2024).
What is the upper limit of normal for TRVmax?
TRVmax <2.5 m/s is considered the upper limit of normal (Blagodir, 2024).
How is pulmonary artery pressure calculated from TR?
In the absence of RVOT obstruction, RVSP is assessed by TRVmax and RAP; RVSP corresponds to SPAP (Blagodir, 2024).
What is assessed during tricuspid valve stress echocardiography?
At each stage of the protocol, the severity of TR, peak TR velocity, and systolic pulmonary artery pressure are assessed, describing the dynamics as no change or increase (ASE 2025).