Discussion The results of this systematic review have the potential to benefit thous and s of patients worldwide as well as healthcare systems and healthcare economy .
Background Atrial fibrillation is the most common arrhythmia of the heart with a prevalence of approximately 2 % in the western world .
Atrial flutter , another arrhythmia , occurs less often with an incidence of approximately 200,000 new patients per year in the USA .
Patients with atrial fibrillation and atrial flutter have an increased risk of death and morbidities .
The management of atrial fibrillation and atrial flutter is often based on interventions aim ing at either a rhythm control strategy or a rate control strategy .
The evidence on the comparable effects of these strategies is unclear .
This protocol for a systematic review aims at identifying the best overall treatment strategy for atrial fibrillation and atrial flutter .
Transthoracic cardioversion of atrial fibrillation: comparison of rectilinear biphasic versus damped sine wave monophasic shocks.
BACKGROUND Clinical studies have shown that biphasic shocks are more effective than monophasic shocks for ventricular defibrillation . The purpose of this study was to compare the efficacy of a rectilinear biphasic waveform with a st and ard damped sine wave monophasic waveform for the transthoracic cardioversion of atrial fibrillation . METHODS AND RESULTS In this prospect i ve , r and omized , multicenter trial , patients undergoing transthoracic cardioversion of atrial fibrillation were r and omized to receive either damped sine wave monophasic or rectilinear biphasic shocks .  Patients r and omized to the monophasic protocol ( n=77 ) received sequential shocks of 100 , 200 , 300 , and 360 J. Patients r and omized to the biphasic protocol ( n=88 ) received sequential shocks of 70 , 120 , 150 , and 170 J. First-shock efficacy with the 70-J biphasic waveform ( 60 of 88 patients , 68 % ) was significantly greater than that with the 100-J monophasic waveform ( 16 of 77 patients , 21 % , P<0.0001 ) , and it was achieved with 50 % less delivered current ( 11+/-1 versus 22+/-4 A , P<0.0001 ) . Similarly , the cumulative efficacy with the biphasic waveform ( 83 of 88 patients , 94 % ) was significantly greater than that with the monophasic waveform ( 61 of 77 patients , 79 % ; P=0.005 ) . The following 3 variables were independently associated with successful cardioversion : use of a biphasic waveform ( relative risk , 4.2 ; 95 % confidence intervals , 1.3 to 13.9 ; P=0.02 ) , transthoracic impedance ( relative risk , 0.64 per 10-Omega increase in impedance ; 95 % confidence intervals , 0.46 to 0.90 ; P=0.005 ) , and duration of atrial fibrillation ( relative risk , 0.97 per 30 days of atrial fibrillation ; 95 % confidence intervals , 0.96 to 0.99 ; P=0.02 ) . CONCLUSIONS For transthoracic cardioversion of atrial fibrillation , rectilinear biphasic shocks have greater efficacy ( and require less energy ) than damped sine wave monophasic shocks
Discussion The results of this systematic review have the potential to benefit thous and s of patients worldwide as well as healthcare systems and healthcare economy .
Background Atrial fibrillation is the most common arrhythmia of the heart with a prevalence of approximately 2 % in the western world .
Atrial flutter , another arrhythmia , occurs less often with an incidence of approximately 200,000 new patients per year in the USA .
Patients with atrial fibrillation and atrial flutter have an increased risk of death and morbidities .
The management of atrial fibrillation and atrial flutter is often based on interventions aim ing at either a rhythm control strategy or a rate control strategy .
The evidence on the comparable effects of these strategies is unclear .
This protocol for a systematic review aims at identifying the best overall treatment strategy for atrial fibrillation and atrial flutter .