Prolonged QT dispersion is a risk factor for cardiac arrhythmias and sudden death in patients with cardiac and peripheral artery diseases, but there is no study about prolonged QT dispersion in patients with ischaemic strokes. The insular cortex may play an important role in the genesis of cardiac arrhythmias and sudden death. In our study with 40 patients suffering from unilateral hemispheric ischaemic stroke, the QT dispersion was analysed and correlated to the location of the cerebral lesion. We found that in patients with involvement of the insular cortex, the QT dispersin is significantly longer than in those without insular involvement. Copyright 1999 S. Karger AG, Basel