CRD Summary: This well-conducted review found that intravenous magnesium is not effective in converting acute onset atrial fibrillation to sinus rhythm in patients with a normal serum magnesium concentration. The addition of intravenous magnesium to digoxin reduces fast ventricular response rates, but is less effective than other calcium antagonists or amiodarone. These findings are likely to be reliable.

CRD Commentary: The review addressed a focused question and inclusion criteria were defined clearly in terms of the study design, intervention and participants.  The literature search was adequate, but did not include specific attempts to locate unpublished studies.  There is therefore a possibility of publication bias, which was assessed in the review.  Appropriate steps were taken to minimise bias and error at all stages of the review process.  Study quality was assessed using appropriate criteria and the results of this assessment were reported clearly in tables, together with other relevant study details.  The decision to pool studies stratified on comparator treatment was appropriate given the data, and heterogeneity was formally assessed.  This was a well-conducted review and the findings are likely to be reliable.