Atrial fibrillation following MCA infarct

초록

Background : Cardiac arrhythmias and EKG changes have been reported following stroke involving insular cortex. Atrial fibrillation (AF), commonly considered as cardiac embolic source, can be induced by stroke itself. We sought AF which is suspected to develop after middle cerebral artery (MCA) infarct, and tried to find relationship with insular cortex involvement and lateralization. Methods : From Inha University Stroke Registry of recent 2 years, 143 MCA territorial infarct patients who admitted within 48 hours after onset were recruited. EKG on admission and follow-up during hospitalization was analyzed. Also MCA infarct was subdivided according to the insular involvement. Patients with recent AF and after-admission AF were compared for AF evolution, risk factors, lesion type and distribution with patients with previous history of AF. Results : Among 143 MCA territorial infarcts, 38 patients had AF on admission (Rt:21; Lt:17). Of those, insular involvement of MCA infarct was noted in 32 patients. All the patients were taken follow-up EKG and AF disappeared in 3 patients (Rt:2; Lt:1) during follow-up. In the remaining 105 MCA infarcts patients, 10 patients subsequently developed new AF within 1 week after hospitalization. All that 10 patients had right-sided MCA infarcts and insular involvement was present in all but one patient. So among 48 MCA infarct with associated AF, 13 AF (Rt:12; Lt:1) were presumed to be the consequence, not the cause of the stroke. Conclusions : As human insular stimulation and inactivation studies have suggested sympathetic influence of right insular cortex, and parasympathetic of the left, it was postulated that AF would be more common in left insular destructive lesion, but it was not always supported in the clinical series. From our study, presumed ‘stroke-induced’ AF was highly associated with right insular lesion. The mechanism of arrhythmogenesis by ischemic stroke might be more complicated than expected, not merely simple inacti