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Updated: Feb 7, 2026
Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
Published on: February 26, 2013
Exclusion of left atrial thrombus by dual-source cardiac computed tomography prior to catheter ablation for atrial
Marc Kottmaier1, Clemens Jilek2, Sophie Berglar2
1Department of Electrophysiology, German Heart Center Munich, Technische Universitaet Munich, Lazarettstr. 36, 80636, Munich, Germany. mkottmaier@web.de.
Insights
Dual-source cardiac-computed tomography (DS-CT) effectively detects left atrial thrombus before atrial fibrillation ablation, offering high sensitivity and specificity. Non-ECG-synchronized DS-CT provides comparable accuracy with lower radiation exposure, suggesting its potential as a primary screening tool.
Area of Science:
- Cardiology
- Radiology
- Medical Imaging
Background:
- Thromboembolic complications following atrial fibrillation (AF) ablation are a significant risk, often caused by left atrial (LA) thrombus formation (TF).
- Transesophageal echocardiography (TEE) is the current standard for excluding LA TF, but alternative imaging modalities are being explored.
Purpose of the Study:
- To compare the sensitivity and specificity of dual-source cardiac-computed tomography (DS-CT) against TEE for detecting LA TF prior to AF ablation.
- To evaluate the impact of ECG-synchronized versus non-ECG-synchronized CT protocols on diagnostic accuracy and radiation exposure.
Main Methods:
- A study involving 622 patients undergoing AF ablation, where both DS-CT and TEE were performed within 48 hours to exclude LA TF.
- Patients' demographics included a mean age of 60 ± 10 years, with 69% males and 61% diagnosed with paroxysmal AF.
- DS-CT protocols were compared: ECG-synchronized in 332 patients and non-ECG-synchronized in 290 patients.
Main Results:
- DS-CT demonstrated 100% sensitivity and 89.2% specificity for LA TF detection, with a 100% negative predictive value.
- In patients with no suspected TF on DS-CT (88.7%), TEE confirmed the absence of thrombus.
- Non-ECG-synchronized DS-CT had significantly lower radiation exposure (136 ± 55 mGy·cm) compared to synchronized (282 ± 287 mGy·cm) with comparable diagnostic accuracy.
Conclusions:
- DS-CT is a highly sensitive imaging technique for detecting LA thrombus in patients undergoing AF ablation, providing valuable anatomical detail.
- Non-ECG-synchronized DS-CT offers a reduced radiation dose with equivalent diagnostic performance to TEE for TF exclusion.
- DS-CT may be considered a primary method for excluding LA TF before AF ablation, potentially improving patient management and safety.
Objectives:
Thromboembolic complications during atrial fibrillation (AF) ablation due to mobilisation of a pre-existing thrombus formation (TF) in the left atrium (LA) are devastating. The gold standard to exclude LA TF is transesophageal echocardiography (TEE). The present study compares sensitivity and specificity of a dual-source cardiac-computed tomography (DS-CT) with TEE for TF exclusion prior to AF ablation. In addition, CT protocols with and without ECG synchronized were evaluated.
Methods:
In 622 patients, DS-CT as well as TEE to exclude TF was performed less than 48 h prior to AF ablation. Mean age of patients was 60 ± 10 years (69% males, 61% paroxysmal AF). During DS-CT, 280 patients (45%) were in AF. An ECG-synchronized DS-CT was performed in 332 patients, whereas 290 patients underwent DS-CT without ECG synchronization.
Results:
In all patients without suspected TF on DS-CT (n = 552; 88.7%), no thrombus was found on TEE. A TF was suspected on DS-CT in 70 patients, of whom only three patients showed TF on TEE. No TF was detected in the other 67 patients (Fig. 1). Overall, sensitivity for TF detection in DS-CT was 100% and specificity was 89.2% (positive predictive value 4.3%, negative predictive value 100%). The CT protocol (ECG-synchronized versus non-ECG-synchronized) had no significant influence on diagnostic accuracy. Mean dose length product during DS CT was 282 ± 287 mGy cm (synchronized) versus 136 ± 55 mGy cm (non-synchronized) with p < 0.0001.
Conclusions:
DS-CT is a highly sensitive method for LA thrombus detection in patients undergoing AF ablation. It delivers additional anatomic details of pulmonary veins and LA anatomy with an acceptable radiation exposure. Non-ECG-synchronized DS-CT showed a significantly lower radiation exposure, whereas diagnostic accuracy was comparable. Therefore, DS-CT might serve as primary method to exclude LA TF in patients undergoing AF ablation.
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