Panoramic optical mapping shows wavebreak at a consistent anatomical site at the onset of ventricular fibrillation.

Aims: The first seconds of ventricular fibrillation (VF) are well organized and can consist of just one to two rotating waves (rotors). New rotors are spawned when local propagation block causes wave fragmentation. We hypothesized that this process, which leads to fully developed VF, begins at a consistent anatomic site.