ObjectiveTo systematically review the clinical efficacy of potassium magnesium aspartate in prevention of arrhythmia after cardiac heart surgery. MethodsSearching PubMed, MEDLINE, EMbase, The Cochrane Library (Issue 5, 2014), CNKI, VIP and WanFang Data to collect randomized controlled trials (RCTs) about the clinical efficacy of potassium magnesium aspartate in prevention of arrhythmia after cardiac heart surgery from the date of establishment of the databases to May 2014. Literature screening according to the inclusion and exclusion criteria, data extraction and methodological quality assessment of the included studies were completed by two reviewers independently. Meta-analysis was then conducted by RevMan 5.2 software. ResultsA total of nine RCTs involving 825 patients were enrolled. The results of meta-analysis indicated that: compared with the control group, timely giving supplement of potassium magnesium aspartate before and after surgery significantly reduced the incidences of arrhythmia (OR=0.25, 95%CI 0.09 to 0.69, P=0.008), premature beats (OR=0.08, 95%CI 0.03 to 0.23, P < 0.000 01), tachycardia (OR=0.29, 95%CI 0.17 to 0.49, P < 0.000 01) and 24 h low cardiac output (OR=0.27, 95%CI 0.10 to 0.72, P=0.009); and increased auto-resuscitation rates (OR=12.16, 95%CI 4.82 to 30.68, P < 0.000 01), with significant differences. However, the two groups were alike in the incidences of atrial fibrillation (OR=0.05, 95%CI-0.16 to 0.05, P=0.34) and ventricular fibrillation (OR=1.24, 95%CI 0.73 to 2.13, P=0.43). ConclusionPotassium magnesium aspartate is effective in prevention of arrhythmias after cardiac surgery, and protective to the myocardium. However, compared with conventional treatment it cannot significantly decrease the incidences of atrial fibrillation and ventricular fibrillation. Due to the limited quantity and quality of the included studies, more multi-centre high quality RCTs with large sample size are needed to verify the above conclusion.