Tricuspid regurgitation
Five grades (up to torrential), mechanism including leads, RV and PA — and who benefits from intervention.
Numbers to remember
- Severe: VC ≥7 mm, EROA ≥0.40 cm²; massive VC 14–20 mm; torrential VC ≥21 mm [81,104]
- 3D VCA: severe 75–94, massive 95–114, torrential ≥115 mm² [81]
- Hepatic vein systolic reversal supports severe TR [4]
- Moderate or greater TR is independently associated with mortality in the community [184]
Questions echo must answer
Tricuspid regurgitation was long ignored. Community data show that moderate or greater TR independently predicts death [184], and transcatheter therapy now improves quality of life [65]. Echo defines the mechanism, grade (the extended five-grade scheme) and RV–PA status, which determines who is likely to benefit [6,81,183].
- MechanismPrimary (leaflet disease, endocarditis, carcinoid, rheumatic), secondary ventricular (PH, RV cardiomyopathy), secondary atrial (AF, annular dilatation), or device-lead related [6,183,194].
- SeverityVC, PISA EROA, 3D VCA, CW density and shape, hepatic vein flow [4,81,104].
- RVSize and function, RV–PA coupling [3,77].
- PA pressurePre-capillary PH makes intervention less effective [6].
- CongestionIVC, hepatic and renal consequences.
Acquisition protocol
- RV-focused A4C, RV inflow, PSAXLeaflet morphology and coaptation gap; lead position and impingement [194].
- Colour zoomVC in two orthogonal views (A4C and RV inflow); PISA with the baseline shifted [4].
- 3DVena contracta area when available [81,104].
- CWDensity; a triangular, early-peaking envelope; peak velocity (which may be low in torrential TR) [4].
- Tricuspid inflowE >1.0 m/s supports severe TR [4].
- Hepatic vein PWSystolic blunting or reversal [4].
- RVAnnulus diameter, RVD1, TAPSE, S′, FAC, RV strain; TAPSE/PASP [3,77].
- IVCSize and collapse.
- Mechanism (primary / ventricular / atrial / lead)
- VC (two views)
- PISA EROA / 3D VCA
- CW density and shape
- Hepatic vein flow
- Tricuspid annulus and RV size
- RV function and TAPSE/PASP
- PASP (beware underestimation)
- Grade (five-grade scheme)
Diagnosis & severity
| Parameter | Mild | Moderate | Severe | Massive | Torrential |
|---|---|---|---|---|---|
| VC biplane (mm) | <3 | 3–6.9 | 7–13 | 14–20 | ≥21 |
| EROA PISA (mm²) | <20 | 20–39 | 40–59 | 60–79 | ≥80 |
| 3D VCA (mm²) | — | — | 75–94 | 95–114 | ≥115 |
Sources: Hahn & Zamorano's extension of the ASE/EACVI grading [4,81,104]. Hepatic vein systolic reversal, a dense triangular CW envelope and tricuspid E >1.0 m/s support severe TR [4].
Thresholds that change management
- Severe TR at left-sided valve surgery → concomitant tricuspid surgery. Moderate TR with a dilated annulus (≥40 mm or >21 mm/m²) → consider repair at the same operation [6,7].
- Isolated severe symptomatic TR without severe RV dysfunction or severe pre-capillary PH → surgery or transcatheter therapy at a heart valve centre [6].
- Transcatheter edge-to-edge repair reduced TR and improved quality of life in TRILUMINATE [65].
- Lead-related TR → consider lead management before or during valve intervention [6,194].
- Severe RV dysfunction or PASP disproportionate to the left heart → reconsider intervention and investigate PH [6,8].
Pitfalls & mimics
PitfallIn massive and torrential TR, the RV and RA pressures equalise. The TR velocity may be only 2 m/s, so PASP is badly underestimated. Do not call the PA pressure "normal" [3,4].
- Respiration changes TR severity. Grade over several cycles and note inspiration.
- A single-plane VC underestimates an elliptical orifice. Use two views or 3D [81].
- Leads cause shadowing that hides the jet origin. Look in multiple views, or use 3D or TOE [194].
- IVC dilatation also occurs in athletes and with positive-pressure ventilation.