Abstract
Cardiac arrhythmias are a major cause of death and disability. Despite the clinical need and the importance of studying arrhythmia mechanisms in humans, a noninvasive imaging modality for cardiac electrophysiology is not yet available for routine application. Here we describe such a noninvasive imaging modality, electrocardiographic imaging (ECGI), and provide examples of its application in various (normal and abnormal) cardiac rhythms.