21 Specifications and Safety Clinical Performance Summary - Cardioversion
294
Clinical Performance Summary - Cardioversion
An international, multicenter, prospective, double-blinded, randomized, clinical trial was conducted to
assess the effectiveness of the SMART Biphasic waveform in treatment of atrial fibrillation (AF), as
compared to monophasic waveforms. The primary objective of the study was to determine the required
energy for cardioversion of AF using the SMART Biphasic waveform, as compared with a monophasic
damped sine waveform.
This section summarizes the methods and results of this study.
Methods
Patients enrolled for this study were adults scheduled for elective cardioversion of AF at one of 11
clinical sites. Clinicians used both a defibrillator delivering the SMART Biphasic waveform, and one
delivering a monophasic waveform. A sequence of up to five shocks was administered: four with the
initial defibrillator, and a fifth cross-over shock was delivered with the other defibrillator if necessary.
The sequence of energy settings was 100J, 150J, 200J through the first three shocks on either type of
defibrillator. A fourth shock, if necessary, was delivered at 200J if the initial defibrillator was biphasic,
and at 360J if the initial defibrillator was monophasic. The cross-over shock was 360J monophasic if
the initial defibrillator was biphasic, and 200J biphasic if the initial defibrillator was monophasic.
Successful cardioversion was defined as the occurrence of two P waves uninterrupted by atrial
fibrillation within 30 seconds of the shock.
Results
Randomization to the use of monophasic or SMART Biphasic defibrillators was done in 212 elective
cardioversions involving 210 patients at eleven clinical sites in the United States and Europe. Of these,
203 results met the protocol criteria for inclusion in this analysis. The biphasic and monophasic groups
were similar in terms of age, sex, weight, current medical history, cause of heart disease, and estimated
ejection fraction.
The 150J SMART Biphasic waveform successfully converted far more patients with an initial 100J
shock (60% compared with 22% for the monophasic waveform), and successfully converted patients at
least as well with a maximum energy of 200J as the monophasic did with its maximum energy of 360J
(91% compared to 85% for the monophasic waveform). Overall, the biphasic waveform required fewer
shocks (1.7, compared to 2.8 for the monophasic waveform) and lower delivered energy (217J,
compared to 548J for the monophasic waveform). Outcomes are summarized in Table 83.
To Next Page
Loading...
