Arentz 2007.

Methods	Randomised controlled trial
Participants	Inclusion criteria: consecutive patients with highly symptomatic, drug‐refractory paroxysmal or persistent episodes of AF. 110 patients were included and assigned into two groups evenly. Age: 56+/‐10 years in small isolation area group, and 55+/‐10 years in large isolation area. % of male: 39/55 (70.9%) in small isolation area group and 44/55 (80%) in large isolation group. Follow‐up: 15+/‐4 months. Location: Herz‐Zentrum, Bad Krozingen, Germany.
Interventions	Small area of PV ablation compared with large area of PV ablation.
Outcomes	Success rate, recurrence of AF, complications
Notes	PV: Pulmonary vein.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient detail was provided.
Allocation concealment (selection bias)	Unclear risk	B‐Unclear. The authors did not depict allocation concealment method.
Blinding	High risk	Blinding was not reported.
Incomplete outcome data addressed	High risk	There were no patients withdrawn or lost to follow up.
Adequate sequence generation	Unclear risk	B‐Unclear. The authors did not depict adequate sequence generation.