Recent data suggest that a large proportion of ischemic strokes are due to embolic phenomena from the heart. Atrial fibrillation appears to be one of the principal causes of embolization. If electrophysiologic parameters are considered as determining factors, the existence of atrial hypervulnerability in patients with embolic strokes is significant, when arrhythmia has been excluded as an etiology. This study suggests that an aggressive approach to early diagnosis and management through electrophysiologic studies might aid in preventing future neurologic attacks.