Can Tricuspid Regurgitation Cause Atrial Fibrillation?
The relationship between tricuspid regurgitation (TR) and atrial fibrillation (AF) is bidirectional—AF more commonly causes TR through annular remodeling, but TR can also contribute to AF development through right atrial enlargement and dysfunction.
The Predominant Direction: AF Causes TR
The guideline evidence clearly establishes that AF-induced annular remodeling is a major determinant of secondary TR 1. This mechanism is so well-recognized that guidelines specifically address "atrial functional tricuspid regurgitation" as a distinct entity, recommending TV repair with annuloplasty (Class IIb) in AF patients with progressive RV dysfunction and/or dilation despite guideline-directed medical therapy 1.
The 2020 ACC/AHA guidelines note that severe symptomatic isolated TR is "commonly associated with device leads and atrial fibrillation" 2, reinforcing AF as a primary driver of TR rather than the reverse.
The Reverse Relationship: TR Can Contribute to AF
While less emphasized in guidelines, recent research demonstrates that TR is independently associated with AF development:
- In acute ischemic stroke patients, TR was strongly associated with AF (adjusted OR 4.87) regardless of severity (mild TR: aOR 4.57; moderate-to-severe TR: aOR 7.05) 3
- Among patients without known AF at admission, TR was associated with newly diagnosed AF during hospitalization and 1-year follow-up (aOR 2.68) 3
- Post-TAVR registry data shows AF/AFL independently predicted TR progression (sub-distribution hazard ratio 1.82), but this primarily reflects AF worsening existing TR 4
The Mechanistic Explanation
The bidirectional relationship operates through these pathways:
AF → TR pathway (dominant):
- AF causes right atrial enlargement and tricuspid annular dilation
- Loss of atrial contraction reduces valve coaptation
- Persistent AF duration directly correlates with TR severity 5, 6
TR → AF pathway (less common):
- Chronic TR causes right atrial stretch and enlargement
- Right atrial remodeling creates substrate for atrial arrhythmias
- Elevated left atrial pressure in AF patients with TR further promotes right heart remodeling 6
Clinical Implications
When evaluating patients with both TR and AF:
- Assume AF is the primary driver unless evidence suggests primary valvular pathology (trauma, congenital dysplasia, endocarditis) 7
- Persistent AF duration, female sex, age ≥65 years, and heart failure are key predictors of significant TR in AF patients 5
- Elevated left atrial systolic pressure, mitral regurgitation, and AF duration are independent predictors of significant TR 6
- Consider 3D-transesophageal echocardiography when TR severity seems disproportionate to AF burden, as structural valve abnormalities may be missed on standard TTE 7
Bottom Line
While TR can theoretically contribute to AF through right atrial remodeling, the overwhelming clinical reality is that AF causes TR through annular dilation. The guideline focus on "atrial functional TR" and the consistent research showing AF as a predictor of TR progression—rather than the reverse—confirms this directionality. When both conditions coexist, treat the AF aggressively with rhythm control and address TR surgically when indicated by symptoms, RV dysfunction, or during concomitant left-sided valve surgery 1, 2.