A 52-year-old woman with a 10-year history of atrial fibrillation presents with a new diastolic murmur at the left sternal border that increases with inspiration. She is hemodynamically stable. Transthoracic echocardiography shows a thickened tricuspid valve with reduced mobility. Which investigation is most appropriate to determine the etiology of tricuspid regurgitation and guide further management?

Explanation

## Diagnosis: Secondary Tricuspid Regurgitation (likely Rheumatic) The clinical presentation—long-standing atrial fibrillation, diastolic murmur at the left sternal border increasing with inspiration (Carvallo sign), thickened tricuspid valve with reduced mobility—suggests **rheumatic tricuspid stenosis with regurgitation**. ### Why Transesophageal Echocardiography (TEE)? **Key Point:** **Transesophageal echocardiography (TEE)** is the **most appropriate next investigation** when TTE findings are inconclusive or when detailed anatomic assessment of the tricuspid valve is needed to differentiate primary (organic) from secondary (functional) TR and to identify the underlying etiology. **High-Yield:** TEE advantages in tricuspid valve disease: - **Superior image quality** — the esophagus is posterior, providing excellent views of the right-sided valves - **Direct visualization** of valve leaflet morphology, commissural fusion, and vegetations - **Real-time assessment** of valve motion and coaptation during the cardiac cycle - **Identification of rheumatic changes** — leaflet thickening, restricted motion, commissural fusion - **Detection of associated pathology** — left atrial thrombus (relevant in AF), septal defects, endocarditis - **Measurement of regurgitant jet** and assessment of RV size/function - **Guidance for intervention** — if balloon mitral commissurotomy or surgical valve repair is planned **Clinical Pearl:** The **diastolic murmur increasing with inspiration** (Carvallo sign) indicates tricuspid stenosis; when combined with AF and a thickened valve on TTE, rheumatic etiology is highly likely, and TEE can confirm this and assess suitability for percutaneous or surgical intervention. ### Primary vs. Secondary TR | Feature | Primary (Organic) | Secondary (Functional) | |---------|-------------------|------------------------| | Valve leaflets | Thickened, restricted, fused | Normal or thin | | Etiology | Rheumatic, endocarditis, carcinoid, trauma | RV dilatation, AF, pulmonary hypertension | | TEE finding | Commissural fusion, vegetations | Annular dilatation, leaflet tethering | | Management | Valve repair/replacement | Treat underlying cause | **Tip:** In a patient with AF and a structurally abnormal tricuspid valve on TTE, TEE is superior for confirming rheumatic etiology and assessing candidacy for intervention.