36793
document
A pilot study of a low-tilt biphasic waveform for transvenous cardioversion of atrial fibrillation : improved efficacy compared with conventional capacitor-based waveforms in patients . BACKGROUND The optimal waveform tilt for defibrillation is not known . Most modern defibrillators used for the cardioversion of atrial fibrillation ( AF ) employ high-tilt , capacitor-based biphasic waveforms . METHODS We have developed a low-tilt biphasic waveform for defibrillation . This low-tilt waveform was compared with a conventional waveform of equivalent duration and voltage in patients with AF . Patients with persistent AF or AF induced during a routine electrophysiology study ( EPS ) were randomized to receive either the low-tilt waveform or a conventional waveform . Defibrillation electrodes were positioned in the right atrial appendage and distal coronary sinus . Phase 1 peak voltage was increased in a stepwise progression from 50 V to 300V . Shock success was defined as return of sinus rhythm for > /=30 seconds . RESULTS The low-tilt waveform produced successful termination of persistent AF at a mean voltage of 223 V ( 8.2 J ) versus 270 V ( 6.7 J ) with the conventional waveform ( P = 0.002 for voltage , P = ns for energy ) . In patients with induced AF the mean voltage for the low-tilt waveform was 91V ( 1.6 J ) and for the conventional waveform was 158 V ( 2.0 J ) ( P = 0.005 for voltage , P = ns for energy ) . The waveform was much more successful at very low voltages ( less than or equal to 100 V ) compared with the conventional waveform ( Novel : 82 % vs Conventional 22 % , P = 0.008 ) . CONCLUSION The low-tilt biphasic waveform was more successful for the internal cardioversion of both persistent and induced AF in patients ( in terms of leading edge voltage ) .
36794
Intervention_Physical
low-tilt biphasic waveform
36795
Intervention_Pharmacological
low-tilt waveform
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Intervention_Pharmacological
conventional waveform
36797
Intervention_Physical
low-tilt waveform
36798
Intervention_Physical
conventional waveform
36799
Intervention_Physical
low-tilt waveform
36800
Intervention_Pharmacological
conventional waveform
36801
Intervention_Pharmacological
low-tilt biphasic waveform
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Outcome_Other
efficacy
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Outcome_Physical
return of sinus rhythm
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Outcome_Physical
termination of persistent AF
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Outcome_Other
mean voltage
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Participant_Condition
atrial fibrillation
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Participant_Condition
Patients with persistent AF or AF induced during a routine electrophysiology study