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Three Part Question

In [a patient with new onset AF who needs urgent electrical cardioversion] is [antero-posterior better than antero-lateral paddle position] at [reverting the patient to sinus rhythm]?

Clinical Scenario

A 60 year old man presents to the emergency department with a history of sudden onset palpitations. This is associated with some mild chest discomfort and breathlessness. On examination he is in atrial fibrillation at a rate of 180, and has a BP of 95/60. He looks pale and sweaty. You feel he needs urgent electrical cardioversion and wonder whether the paddle position used will affect your success rate.

Search Strategy

Medline 1966-09/04 using the OVID interface and The Cochrane Library, Issue 3, 2004 via the NeLH.
Medline: ([exp atrial fibrillation OR AF.mp] AND [exp electric countershock OR electrode position.mp OR electrical cardioversion.mp OR DC cardioversion.mp]) LIMIT to human, English language AND adults.
Cochrane: [paddle] next [position]

Search Outcome

Altogether 954 papers were found of which 5 were relevant to the question. No additional papers were found in the Cochrane Library.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Mathew TP et al, 1999, UK	90 patients Elective Antero-Lateral (AL) vs. Antero-Posterior (AP) 100J then 200J, 300J, 360J	Prospective, randomised	Cardioversion success rate	38/45 success for AL vs. 33/45 for AP p=0.42	No power Randomisation method not explicit Elective patients
			Mean (SD) energy used	223 (96.1) J for AL vs. 232 (110) J for AP
			Mean (SD) thoracic impedance on 1st shock	77.5 (18.4) Ohms AL vs. 73.7 (18.7) Ohms AP p=0.34
Alp NJ et al, 2000, UK	59 patients with persistent AF AP vs. AL (360 J)	RCT cross-over	Cardioversion success rate on 1st 360J DC shock	With first 360J AL more successful 18/30 vs.10/29 for AP (p=0.048)	Small numbers Elective Patients with persistent AF
			Cardioversion 2nd 360J shock	4/19 for AL vs. 5/12 for AP p=0.22
Botto GL et al, 1999, Italy	301 patients with stable AF AL vs. AP 3J/kg then 4J/kg then 4J/kg in alternative position	Prospective randomised controlled trial	Success rate at initial 3J/Kg shock	87/151 success for AL vs. 100/150 for AP	No power calculation Randomisation method not explicit All elective with chronic AF
			Cumulative success rate after 1st 4J/Kg shock	114/151 for AL vs. 131/150 for AP (p=0.013)
			Cumulative success after 2nd 4J/Kg shock	140/150 for AL vs. 140/150 for AP p=NS
Kirchhof P et al, 2002, Germany	108 patients with persistent AF Elective cardioversion (50-360J) AP vs. AL	RCT cross-over (if no response in initial paddle position at 360J)	Cardioversion success rate in initial paddle positions	50/52 for AP vs. 44/56 for AL p=0.009	Elective patients with persistent AF
			Cardioversion if initial position failed	8/12 cardioverted when crossed from AL to AP. No success in those AP to AL (2 patients)
Chen CJ & Guo GB, 2003, Japan	70 patients with persistent AF (>1month). AL (31 patients) vs. AP (39 patients) Step up protocol 100, 150, 200, 300, 360 joules	Randomised controlled trial	Cardioversion success at 100J	AP vs. AL 23% vs.19.4% p=NS	Small, low powered study Only looks at those with persistent AF in an elective setting (excluded those with new onset AF, 1 month) No randomisation details
			Cumulative Cardioversion success at 150J	AP vs. AL 41% vs. 45.2% p=NS
			Cumulative Cardioversion success at 200J	AP vs. AL 66.7% vs. 74.2% p=NS

Comment(s)

AF is a common problem encountered in the emergency department. These papers shows that some good quality research has been done on cardioversion but not in the emergency setting. The 5 best papers show conflicting results regarding the positioning of paddles in elective cardioversion, the most recent showing no difference between the 2 positions. In our clinical scenario the AP position may be difficult to achieve in such an unwell, shocked patient.

Clinical Bottom Line

There is little evidence to suggest that paddle position significantly influences the success of cardioversion emergency department patients with AF.

References

1. Mathew TP, Moore A, McIntyre M, et al. Randomised comparison of electrode positions for cardioversion of atrial fibrillation. Heart 1999;81(6):576-579.
2. Alp NJ, Rahman S, Bell JA, et al. Randomised comparison of antero-lateral versus antero-posterior paddle positions for DC cardioversion of persistent atrial fibrillation. Int J Cardiol 2000;75(2-3):211-216.
3. Botto GL, Politi A, Bonini W, et al. External cardioversion of atrial fibrillation: Role of paddle position on technical efficacy and energy requirements. Heart 1999;82(6):726-730.
4. Kirchhof P, Eckardt L, Loh P, et al. Anterior-posterior versus anterior-lateral electrode positions for external cardioversion of atrial fibrillation: A randomised trial. Lancet 2002;360(9342):1275-1279.
5. Chen CJ, Guo GB. External cardioversion in patients with persistent atrial fibrillation: a reappraisal of the effects of electrode pad position and transthoracic impedance on cardioversion success. Jpn Heart J 2003;44(6):921-32.