Stroke remains a major health concern and a large public health burden. In the past two decades, the age-standardized rate of stroke mortality has decreased; however, the absolute number of strokes and people who live with its consequences has been increasing every year 1.
With regard to ischemic strokes, several classification systems have been proposed. The widely and commonly used TOAST classification divides ischemic stroke into 5 groups: large artery thrombotic strokes, small penetrating artery thrombotic strokes lacunar strokes , cardiogenic embolic strokes, cryptogenic strokes of unknown cause and strokes associated with other causes 2. Small brain embolization may be asymptomatic and is termed silent ischemic stroke. However, silent ischemic stroke may not be entirely asymptomatic, as there may be evidence of cognitive, gait or other functional impairments which may not be evident on common bed-side examination 4.
Thus, a silent stroke may be a cerebral infarction that was unnoticed, overlooked or disregarded 4. It is well known atrial fibrillation AF poses a risk of ischemic stroke, and stroke contributes significantly to the increased mortality associated with AF 5 , 6.
Apart from manifest strokes, silent strokes are also found in patients that suffer from AF. The treatment of AF consists of antiarrhythmic drug therapy or ablation procedures, mainly catheter-based pulmonary venous isolation. Catheter-based pulmonary venous isolation has been shown to be superior to treatment by antiarrhythmic drugs in randomized studies 7. However, the efficacy of catheter ablation in patients with the non-paroxysmal form of AF remains limited.
Based on the efficacy of the surgical maze procedure, that consists of exactly described set of lesions in atria being performed during open chest surgery on cardiopulmonary bypass, its less invasive variation, i. As in any invasive cardiac procedure, ablation poses a potential risk for periprocedural embolization, especially to the brain 9. Complication rates including brain embolization may differ significantly between different invasive ablation procedures. A comparison of silent stroke risk between percutaneous catheter-based and thoracoscopic epicardial ablation has never been performed.
