Most Common Causes of Tricuspid Regurgitation
More than 90% of severe tricuspid regurgitation cases are functional (secondary) in nature, caused by heart failure, left-sided heart valve disease, device-related complications, or chronic atrial fibrillation 1.
Primary Classification: Functional vs. Primary TR
Tricuspid regurgitation fundamentally divides into two categories based on whether the valve leaflets themselves are structurally damaged:
Functional (Secondary) TR - The Dominant Form
Functional TR is by far the most common type and occurs when the tricuspid valve leaflets are structurally normal but fail to coapt properly due to right ventricular dysfunction, annular dilatation, or geometric distortion 2. The mechanism involves:
- RV dysfunction following pressure and/or volume overload with structurally intact leaflets 2
- Annular dilatation and flattening - the normal saddle-shaped annulus becomes larger, flatter, and more circular 3
- Papillary muscle displacement and leaflet tethering from RV dilation, preventing complete coaptation 3
The specific underlying causes of functional TR include:
- Left-sided heart valve disease (particularly mitral valve disease, most commonly rheumatic) 2, 4
- Heart failure with reduced ejection fraction - associated with only 34% five-year survival when severe TR coexists 5
- Pulmonary hypertension and chronic lung disease (cor pulmonale) 2, 3
- Chronic atrial fibrillation with chamber enlargement 1, 6
- Ischemic heart disease (24% of cases in one series) 7
- Cardiomyopathy 2, 7
Primary (Organic) TR - Less Common
Primary TR results from structural damage to the tricuspid valve apparatus itself 2. The causes include:
- Infective endocarditis (especially in intravenous drug users) 2
- Device-related damage from pacemaker/ICD leads and right heart biopsies 1, 6
- Rheumatic heart disease (affecting the valve directly) 2
- Carcinoid syndrome 2
- Myxomatous disease 2
- Ebstein's anomaly and congenitally dysplastic valves 2
- Drug-induced valve disease 2
- Endomyocardial fibrosis 2
- Thoracic trauma and iatrogenic valve damage 2
Clinical Context
The bidirectional relationship between TR and right heart failure is critical to understand: TR causes RV volume overload, while RV remodeling in heart failure promotes TR progression through annular dilatation and leaflet tethering 8. This creates a vicious cycle where each condition worsens the other.
Common Pitfall
TR is frequently overlooked and underdiagnosed 1. The guidelines emphasize that more than 90% of severe TR represents functional phenotypes, yet systematic screening and surveillance recommendations are lacking 1. Early detection through serial echocardiographic evaluation during routine surveillance for other cardiac conditions is essential to prevent progression to end-stage right-sided heart failure where intervention becomes futile 1.
Approximately 13% of apparently normal adults may have some degree of TR without any identifiable secondary cause 7, though this is typically mild and not clinically significant.