Figure 6.
Average HRV values for RMSSD, HF log, PNS index, pNN50, and Mean RR during prebypass, preclamp, clamp, postclamp, and postbypass phases, collapsed across all three perfusionists during 23 total cases. HF = high frequency power band; HRV = heart rate variability; mean RR = average interval duration between consecutive R-peaks; pNN50 = percentage of normal-to-normal peaks differing by at least 50 ms; PNS = parasympathetic nervous system; RMSSD = root mean square of the successive differences.