Higher energy monophasic DC cardioversion for persistent atrial fibrillation: is it time to start at 360 joules?

Ann Noninvasive Electrocardiol. 2003 Apr;8(2):121-6. doi: 10.1046/j.1542-474x.2003.08205.x.

Abstract

Background: Electrical direct-current cardioversion (DCCV) has become a routine therapy for atrial fibrillation (AF), although some uncertainty remains regarding the optimal energy settings.

Aims: This study examines whether the use of a higher initial energy monophasic shock of 360 joules (J) for external DCCV, in patients with persistent AF would prove more effective, yet as safe, as the use of a lower initial energy 200 J shock.

Methods: A cohort of 107 patients with persistent AF was prospectively randomized to an initial synchronized DCCV shock of 360 J versus 200 J (n = 50 vs 57), followed by a similar shock sequence thereafter of four further shocks of 360 J for the two groups. In all patients the levels of troponin I (cTnI) were measured precardioversion and 18-20 hours later, the following day. In a subgroup of 36 patients in each group, the levels of creatine kinase (CK) and aspartate transaminase (AST) were measured pre- and 18-20 hours postcardioversion.

Results: The success rate for DCCV was significantly higher in the 360 J group compared to the 200 J group (96.0% vs 75.4%, P = 0.003). The mean CK IU/L levels (1137.5.0 vs 2411.8, P = 0.014) and AST levels (39.83 vs 52.86, P = 0.010) were significantly lower in the 360 J group compared to the 200 J group. There was no statistical rise in cTnI (microg/L) in either group (P = 1.00). The average number of shocks delivered (1.84 vs 2.56, P = 0.006) was significantly less in the 360 J group than in the 200 J group, although total energy requirements for DCCV were similar for the two groups (662.4 J vs 762.4 J, P = 0.67).

Conclusion: For patients with persistent AF the use of a higher initial-energy monophasic shock of 360 J achieves a significantly greater success rate, with less skeletal muscle damage (and no cardiac muscle damage) as compared with the traditional starting energy of a 200 J DC shock.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Atrial Fibrillation / therapy*
  • Electric Countershock / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Single-Blind Method