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Updated: May 31, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Postablation asymptomatic cerebral lesions: long-term follow-up using magnetic resonance imaging
Thomas Deneke1, Dong-In Shin, Osman Balta
1Department of Electrophysiology, Academic Heart Center Cologne-Porz, Cologne, Germany. thomas.deneke@rub.de
Background:
Catheter ablation of atrial fibrillation (AF) is complicated by cerebral emboli resulting in acute ischemia. Recently, cerebral ischemic microlesions have been identified with diffusion-weighted magnet resonance imaging (MRI).
Objective:
The clinical course and longer-term characteristics of these lesions are not known and were investigated in this study.
Methods:
Of 86 patients, 33 (38%) had new asymptomatic cerebral lesions documented on MRI after catheter ablation for AF; 14 of these 33 (42%) underwent repeat MRI at different time intervals (2 weeks to 1 year) during follow-up, and clinical symptoms as well as size and number of residual lesions were documented.
Results:
In postablation cerebral MRI, 50 new lesions were identified (3.6 lesions/patient) in 14 patients. No patient presented any neurological symptoms. Distribution of the lesions was predominantly in the left hemisphere (60%) and the cerebellum (26%); 52% of the lesions were small (≤3 mm maximum diameter), 42% were medium (4 to 10 mm) and 3 lesions (6%) had a maximum diameter >10 mm. Follow-up MRI after a median of 3 months revealed 3 residual lesions in 3 of 14 patients corresponding to the large acute postablation lesions (>10 mm). The remaining 47 of 50 (94%) of the small or medium-sized lesions were not detectable at follow-up evaluation.
Conclusions:
Most asymptomatic cerebral lesions observed acutely after AF ablation procedures were ≤10 mm in diameter. 94% of all lesions healed without scarring at follow-up >2 weeks after ablation. The larger acute lesions produced chronic glial scars. Neither chronic nor acute lesions were associated with neurological symptoms.
Insights
Most small, asymptomatic cerebral lesions after atrial fibrillation (AF) ablation heal without scarring. Larger lesions may leave chronic glial scars, but neither acute nor chronic lesions caused neurological symptoms in this study.
Area of Science:
- Cardiology
- Neurology
- Radiology
Background:
- Catheter ablation for atrial fibrillation (AF) can lead to cerebral emboli and acute ischemia.
- Diffusion-weighted MRI has identified new cerebral ischemic microlesions post-ablation.
Purpose of the Study:
- To investigate the clinical course and longer-term characteristics of these newly identified cerebral lesions.
- To determine the resolution and potential scarring of these lesions over time.
Main Methods:
- 86 patients undergoing AF ablation were assessed with MRI.
- 33 patients (38%) showed new asymptomatic cerebral lesions.
- 14 of these patients had follow-up MRIs (2 weeks to 1 year) to assess lesion changes and symptoms.
Main Results:
- 50 new lesions were identified in 14 patients, predominantly in the left hemisphere (60%) and cerebellum (26%).
- Most lesions (94%) were small (≤3 mm) or medium (4-10 mm) and undetectable on follow-up MRI.
- Larger acute lesions (>10 mm) resulted in residual lesions and chronic glial scars in 3 patients.
Conclusions:
- The majority of asymptomatic cerebral lesions post-AF ablation are small and resolve without scarring.
- Larger lesions (>10 mm) can lead to chronic glial scars.
- No neurological symptoms were associated with acute or chronic cerebral lesions in this cohort.
