Cardiac imaging for assessment of left atrial appendage stasis and thrombosis

Area of Science:

• Cardiology
• Medical Imaging

Background:

• Atrial fibrillation (AF) is the most common arrhythmia in individuals over 65.
• The left atrial appendage (LAA) is a primary site for thrombus formation in nonvalvular AF.
• Left atrial appendage stasis (SEC) and thrombus are significant concerns in AF management.

Purpose of the Study:

• To review the pathophysiology, assessment, and clinical implications of LAA stasis and thrombus.
• To evaluate current and emerging cardiac imaging modalities for LAA thrombus detection.

Main Methods:

• Review of existing literature on LAA thrombus and imaging techniques.
• Focus on echocardiography (especially TEE), Cardiac CT (CCT), and Cardiac MRI (CMR).

Main Results:

• Transoesophageal echocardiography (TEE) is the gold standard for LAA SEC and thrombus assessment.
• Cardiac CT (CCT) with delayed imaging is an accurate, noninvasive alternative to TEE.
• Cardiac MRI (CMR) requires further prospective validation but offers radiation and contrast avoidance.

Conclusions:

• CCT or CMR may rule out LAA thrombus, potentially avoiding preprocedural TEE.
• Cardiac imaging is crucial for LAA closure devices and electrophysiological studies.
• Further trials comparing imaging modalities against surgical/pathological findings are necessary.