even though VF is a complex phenomenon, it is chaotic and not random.
Because it is chaotic, there are parameters that can be lowered to take the system out of its chaotic behavior.
We found a critical parameter, the slope of the cell’s recovery function from the previous stimulus. When this slope was reduced by a drug, the fibrillation reverted to a simpler non-chaotic behavior.
This was seen first in computer simulation, and subsequently in animal experiments.