This ECG shows ventricular fibrillation. Disorganized wide QRS complexes of relatively low amiplitude are present at a rate of greater than 300 beats per minute. Note the sharp spikes intermittently thoughout the ECG. This is artifact from a biventricular assist device (similar to an artificial heart). This patient has chronic ventricular fibrillation. In this case due to the underlying severe cardiomyopathy, the voltage amplitude is lower than usual.
The rhythm ventricular fibrillation is usally fatal unless rapid defibrillation is performed. This is the rhythm resulting in pre-hospital death in a large majority of acute myocardial infarction patients.