Related Experiment Video
Updated: Jun 9, 2026
Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
Published on: February 26, 2013
ECG-gated dual-source CT for detection of left atrial appendage thrombus in patients undergoing catheter ablation for
Suraj Kapa1, Matthew W Martinez, Eric E Williamson
1Division of Cardiology, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Insights
ECG-gated DSCT effectively detects left atrial appendage thrombus in atrial fibrillation patients before ablation. This imaging method shows 100% sensitivity for thrombus, making it valuable for risk assessment.
Area of Science:
- Cardiology
- Medical Imaging
- Electrophysiology
Background:
- Atrial fibrillation (AF) ablation is a common treatment for symptomatic AF.
- Excluding left atrial appendage (LAA) thrombus is crucial before AF ablation.
- The role of ECG-gated dual-source CT (DSCT) in detecting LAA thrombus is not well-established.
Purpose of the Study:
- To evaluate the diagnostic utility of ECG-gated DSCT for detecting LAA thrombus in patients undergoing AF ablation.
- To determine the sensitivity and specificity of ECG-gated DSCT compared to transesophageal echocardiography (TEE).
Main Methods:
- 255 patients undergoing AF ablation were included.
- ECG-gated DSCT and TEE were performed prior to ablation.
- Two blinded cardiac imagers reviewed DSCT for LAA opacification, comparing findings with TEE results.
Main Results:
- 12.9% of patients had an under-filled LAA on DSCT.
- Four patients had confirmed LAA thrombus by TEE, all identified as abnormal by DSCT.
- ECG-gated DSCT demonstrated 100% sensitivity and 88% specificity for LAA thrombus detection.
Conclusions:
- LAA thrombus is infrequent in AF patients without additional risk factors.
- ECG-gated DSCT is a highly sensitive imaging modality for detecting LAA thrombus.
- In low-risk AF patients (CHADS2=0), ECG-gated DSCT may serve as a standalone diagnostic tool.
Purpose:
Left atrial ablation is increasingly used to treat patients with symptomatic atrial fibrillation (AF). Prior to ablation, exclusion of left atrial appendage (LAA) thrombus is important. Whether ECG-gated dual-source computed tomography (DSCT) provides a sensitive means of detecting LAA thrombus in patients undergoing percutaneous AF ablation is unknown. Thus, we sought to determine the utility of ECG-gated DSCT in detecting LAA thrombus in patients with AF.
Methods:
A total of 255 patients (age 58 ± 11 years, 78% male, ejection fraction 58 ± 9%) who underwent ECG-gated DSCT and transesophageal echocardiography (TEE) prior to AF ablation between February 2006 and October 2007 were included. CHADS2 score and demographic data were obtained prospectively. Gated DSCT images were independently reviewed by two cardiac imagers blinded to TEE findings. The LAA was either defined as normal (fully opacified) or abnormal (under-filled) by DSCT.
Results:
An under-filled LAA was identified in 33 patients (12.9%), of whom four had thrombus confirmed by TEE. All patients diagnosed with LAA thrombus using TEE also had an abnormal LAA by gated DSCT. Thus, sensitivity and specificity for gated DSCT were 100% and 88%, respectively. No cases of LAA filling defects were observed in patients <51 years old with a CHADS2 of 0.
Conclusion:
In patients referred for AF ablation, thrombus is uncommon in the absence of additional risk factors. Gated DSCT provides excellent sensitivity for the detection of thrombus. Thus, in AF patients with a CHADS2 of 0, gated DSCT may provide a useful stand-alone imaging modality.
Related Concept Videos
01:28Imaging Studies for Cardiovascular System V: CT
01:24Cardiac Catheterization III: Left Heart Catheterization
01:30Acute Coronary Syndrome III: Diagnostic Studies
01:25ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
01:21Cardiac Catheterization II: Right Heart Catheterization
01:22Aortic Regurgitation II: Clinical Features and Diagnostic Tests