Figure 1.

Time course of onset of ventricular fibrillation in conscious rats (•) (n=18) and isolated Langendorff perfused rat hearts (○) (n=12) subjected to left coronary artery occlusion at the same site. The distinct phases of VF are termed phase 1 (occurring <2 h after coronary occlusion) and phase 2 (occurring >2 h after coronary occlusion). Reentry and the flow of ‘injury current' are the likely mechanisms responsible for initiation of phase 1 VF, while re-entry and abnormal automaticity are the likely corresponding mechanisms for phase 2 VF. Figure modified and adapted from Curtis (1993).