Background Occult atrial fibrillation (AF) may, in part, explain cryptogenic stroke. A 22% prevalence of subdiaphragmatic visceral infarction (SDVI) among patients with ischemic stroke (IS) due to AF has been reported, using abdominal MRI. We sought to assess the reproducibility of this method and to confirm that SDVI is more prevalent in cases of AF-caused IS than in IS of other etiologies. Methods In consecutive patients admitted to our hospital, we compared SDVI prevalence in three groups: patients with IS due to AF (IS+/AF+ group), patients with stroke of another determined cause (IS+/AF- group) and patients with AF without stroke (IS-/AF+ group). Results A total of 111 patients were included. The median time between inclusion and abdominal MRI was six days. SDVI was more frequent in the IS+/AF+ group ( n = 10; 21.3%), than in IS+/AF- ( n = 1; 3.3%) and IS-/AF+ ( n = 0) groups, p = 0.002. The most frequent localization was the kidney. Conclusions The prevalence of SDVI was higher among patients with AF-caused IS. In cases of cryptogenic stroke, a positive abdominal MRI may suggest occult AF as the cause and identify a high risk of AF in this subgroup of patients.
Keywords: MRI; Stroke; atrial fibrillation; ischemic stroke; stroke subtypes; subdiaphragmatic visceral infarction.