Initial energy setting, outcome and efficiency in direct current cardioversion of atrial fibrillation and flutter
Mark M. Gallagher, MD*,a,
Xiao-Hua Guo, MDa,
Jan D. Poloniecki, PhDa,
Yee Guan Yap, MBa,
David Ward, MDa and
A. John Camm, MDa
a Department of Cardiological Sciences, St. George’s Hospital Medical School, London, United Kingdom
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Figure 1 Characteristics of all 6,390 shocks analyzed. After each unsuccessful shock, the operator could abandon the procedure or progress to the next energy level. The procedure was frequently abandoned before reaching 360 J or after one or two shocks at this power.
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Figure 2 Starting energy used in 2,519 attempts at direct current cardioversion according to the rhythm converted and the duration of that arrhythmia. AF = atrial fibrillation.
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Figure 3 Model of cumulative success using a series of shocks of increasing intensity. AF = atrial fibrillation.
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Figure 4 Analysis of the final shock in each of the 447 failed attempts at cardioversion. The procedure was commonly abandoned prematurely.
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Figure 5 Number of shocks administered per cardioversion attempt. The number was greater in cases where the attempt started at low power, particularly in atrial fibrillation (AF) of longer duration.
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Figure 6 Relationship between initial energy setting and total energy delivered. In recent-onset atrial fibrillation (AF), starting at low energy reduces the total power administered. In AF of long duration, the initial use of 360 J is associated with the lowest total energy use and with a higher success rate.
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