A 35-year-old man with known rheumatic heart disease on warfarin presents with acute dyspnea and hemoptysis. On examination, he has signs of acute pulmonary edema and a new pulsatile hepatomegaly. Chest X-ray shows pulmonary edema with a normal cardiac silhouette. Transthoracic echocardiography shows severe tricuspid regurgitation with right ventricular dilatation and a mobile echo density in the right atrium. Which investigation is most appropriate to confirm the diagnosis and guide immediate management?

Explanation

## Investigation of Choice in Suspected Right Atrial Thrombus ### Clinical Context The patient has: - Rheumatic heart disease with severe tricuspid regurgitation (TR) - Anticoagulation on warfarin (suggesting prior thromboembolic risk) - Acute hemoptysis and pulmonary edema - Mobile echo density in right atrium on TTE - Right ventricular dilatation (consequence of severe TR) This constellation suggests **right atrial thrombus**, a known complication of rheumatic heart disease, particularly with severe TR and atrial dilatation. ### Why Transesophageal Echocardiography (TEE)? **Key Point:** TEE is the gold standard for detecting and characterizing right atrial thrombus, especially when TTE images are suboptimal or when the diagnosis requires higher resolution. **High-Yield:** TEE advantages in this scenario: - Superior spatial resolution for right atrial structures (closer proximity to esophagus) - Better delineation of thrombus morphology (size, mobility, attachment) - Detection of thrombus in the setting of poor transthoracic windows - Real-time assessment of thrombus mobility and risk of embolization - Guides decision for urgent thrombectomy vs. anticoagulation intensification ### Pathophysiology of RA Thrombus in RHD 1. Severe TR → right atrial dilatation 2. Blood stasis in dilated RA → thrombosis 3. Mobile thrombus → risk of pulmonary embolism (explains hemoptysis) 4. Acute pulmonary edema from PE and RV failure **Clinical Pearl:** Hemoptysis in a patient with RHD and RA thrombus suggests pulmonary infarction from PE — a medical emergency requiring urgent imaging confirmation and intervention. ### Comparison of Imaging Modalities | Modality | RA Thrombus Detection | Resolution | Invasiveness | Real-time Guidance | |----------|----------------------|------------|--------------|-------------------| | TTE | Moderate | Moderate | Non-invasive | Yes | | TEE | Excellent | Excellent | Semi-invasive | Yes | | CT angiography | Good | Excellent | Non-invasive | No | | Cardiac cath | Poor | Moderate | Invasive | Yes | ### Management Implications **High-Yield:** TEE findings guide urgent intervention: - **Mobile, large thrombus** → consider urgent surgical thrombectomy - **Small, immobile thrombus** → intensify anticoagulation (heparin, consider thrombolysis) - **Risk stratification** for embolization based on morphology [cite:Harrison 21e Ch 297; Robbins 10e Ch 12]