Progetti Rescue Life, User Manual, Page: 65 / 76

Rescue Life User Manual vers. 3.0 Feb. 2015
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The difference between monophasic and biphasic waveform is qualitatively similar but varies
quantitatively for different parameter values. The fundamental difference is that first phase of
the biphasic pulse acts as a pre-pulse to remove inactivation from the heart cell, accelerating
its recovery, and thereby lowering the activation threshold for defibrillation prior to second
phase of biphasic pulse which is reversed current flow.
Enough Energy for restoring heart rhythm
The Biphasic Truncated Exponential waveform uses lower energy than the Monophasic
waveform. But the lower energy of biphasic shock is more efficient than high energy of the
monophasic shock for defibrillation to restore heart rhythm.
In a multicenter, randomized, controlled trial of 150J biphasic waveform compared with 200J
and 360J monophasic waveforms done in humans, Schneider et al [5] showed that “the 150-J
biphasic waveform defibrillated at higher rates, resulting in more patients who achieved a
return of spontaneous circulation. Although survival rates to hospital admission and discharge
did not differ, discharged patients who had been resuscitated with biphasic shocks were more
likely to have good cerebral performance.”
Positive evidence for safety and clinical effectiveness of biphasic truncated exponential
waveforms for internal and external use was ascertained by the AHA ECC committee. (8), (9)