Related Experiment Video
Updated: Oct 1, 2025

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
Published on: February 26, 2013
Incidence and predictors of left atrial appendage thrombus on transesophageal echocardiography before elective
Felix K Wegner1, Robert Radke2, Christian Ellermann3
1Department of Cardiology II - Electrophysiology, University Hospital Muenster, Albert-Schweitzer-Campus 1, 48149, Muenster, Germany. felix.wegner@ukmuenster.de.
Insights
Transesophageal echocardiography (TEE) before cardioversion is recommended when anticoagulation is less than 3 weeks. Left atrial appendage (LAA) thrombi are rare (3.7%) with direct oral anticoagulants (DOACs), but QRS width may predict reduced LAA flow.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Imaging
Background:
- Guidelines suggest transesophageal echocardiography (TEE) before cardioversion for thrombogenic arrhythmias if anticoagulation is <3 weeks.
- Limited data exist supporting this, especially with direct oral anticoagulants (DOACs).
- Left atrial appendage (LAA) thrombi and flow are critical factors in cardioversion success and safety.
Purpose of the Study:
- To evaluate the incidence of LAA thrombi or reduced LAA flow velocity in patients undergoing pre-cardioversion TEE.
- To identify predictors of LAA thrombi or reduced LAA flow in patients with suboptimal anticoagulation.
- To assess the utility of TEE in the context of modern anticoagulation strategies.
Main Methods:
- Analysis of consecutive elective pre-cardioversion TEE procedures in 512 patients.
- Patients had anticoagulation <3 weeks or uncertain adherence.
- Multivariate logistic regression was used to identify predictors of LAA thrombi or reduced flow.
Main Results:
- LAA thrombi were found in 3.7% of patients.
- Reduced LAA flow velocity, sludge, or both occurred in 8.0% of patients.
- Wider QRS width on ECG predicted LAA thrombi and reduced flow (p=0.008); CHA2DS2-VASc score did not.
Conclusions:
- LAA thrombus is uncommon before elective cardioversion with DOACs.
- Thrombi can occur even in low-risk patients (CHA2DS2-VASc score 0-1).
- ECG QRS width may help identify patients at risk for reduced LAA flow.
Abstract:
Guidelines recommend transesophageal echocardiography (TEE) before cardioversion in thrombogenic arrhythmias when the requirement of ≥ 3 weeks of anticoagulation is not met. Current data to support this approach, especially with direct oral anticoagulants (DOAC), are scarce. We analyzed consecutive elective pre-cardioversion TEE in a high-volume electrophysiology center for the occurrence of left atrial appendage (LAA) thrombi or reduced LAA flow velocity. Possible predictors were recorded and compared in a multivariate logistic regression analysis. Consecutive pre-cardioversion TEE in 512 patients (148 female, median age 69 years) were included. In all patients, indication for TEE was either intake of anticoagulation < 3 weeks before cardioversion or uncertain adherence to the prescribed anticoagulation regimen. Of the 512 TEE, 19 (3.7%) depicted a LAA thrombus. An additional 41 patients (8.0%) showed either a reduced LAA flow velocity (≤ 20 cm/s), LAA sludge, or both. In a multivariate logistic regression analysis, QRS width on admission 12-lead ECG emerged as a possible predictor of LAA thrombus and reduced LAA flow (p = 0.008). Noteworthy, a high CHA2DS2-VASc score was not associated with an increased risk of reduced LAA emptying velocity and LAA thrombi were even found in patients with a CHA2DS2-VASc score of 0 (n = 1) and 1 (n = 1). The presence of LAA thrombus before an elective cardioversion is a rare event in the age of direct oral anticoagulants. However, LAA thrombi occurred even in supposed low-risk individuals according to the CHA2DS2-VASc score. QRS width may aid in identifying patients at risk of reduced LAA flow velocity.
Related Concept Videos
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Cardiac Catheterization III: Left Heart Catheterization
Mitral Valve Prolapse II: Assessment and Management
Aortic Regurgitation II: Clinical Features and Diagnostic Tests
Rheumatic Heart Disease II: Clinical Manifestations and Diagnostic Studies

