Transition of a positive sharp wave to a fibrillation potential

In (A) and (B) the sweep is free running. The traces in (B) represent a continuation of the EMG signal after the last trace in (A). In (C), the waveforms from (A) and (B) are superimposed using amplitude trigger and delay line. Calibration is 200 microV/division and 10 ms/division in (A) and (B), and 100 microV/division and 1 ms/division in (C).