“Adult monomorphic VT (regular form and rate) with a pulse responds well to monophasic or biphasic waveform cardioversion (synchronized) shocks at initial energies of 100 J. If there is no response to the first shock, it may be reasonable to increase the dose in a stepwise fashion. No studies were identified that addressed this issue. Thus, this recommendation represents expert opinion (Class IIb, LOE C).
What do these recommendation classifications mean?
Class IIb: The evidence documented only short-term benefits from the therapy or weakly positive or mixed results. Such recommendations should be interpreted as “can be considered” or “may be useful” or “usefulness/effectiveness is unknown or unclear or not well established.”
Level of evidence C: Expert opinion or studies not related to the specific patient population of the recommendation (including animal models.)
For more details on AHA guideline classifications, see Part 2. Evidence Evaluation. See Table 4 (p. S660).