Endocrine Abstracts

Background: Obesity is associated with cardiac structural changes, repolarization abnormalities and rhythm disorders. The aim of this systematic review is to provide an overview of the literature on obesity, cardiac arrhythmias, obesity associated ECG abnormalities and the effects of bariatric and metabolic surgery.

Methods: A systematic search on the effects of obesity and bariatric surgery on cardiac arrhythmias and associated ECG abnormalities was conducted. The methodological quality of the included studies was rated using the Newcastle-Ottawa scale (NOS) for non-randomized trials. The agreement between the reviewers was assessed with Cohen’s kappa.

Results: Fourteen studies were included with a methodological quality ranging from poor to good. The agreement between the reviewers, assessed with the Cohen’s kappa, was 0.75. Majority of the studies showed a significant decrease of QT interval and related measures after bariatric surgery. Regarding atrial fibrillation the results were conflicting. Seven studies were included in the meta-analysis on effects of bariatric surgery on QTc interval and a significant decrease in QTc interval of –33.62 ms (95% CI : –49.767 to –17.446) was seen. Similar effects were seen after bariatric surgery regarding P-wave dispersion and showed a significant decrease after bariatric surgery (–12.87 ms (95% CI : –17.739 to –8.004)).

Conclusion: Obesity is associated with prolongation of QTc interval, lengthening of P-wave and QTc dispersion and also with rhythm disorders like atrial fibrillation. Significant weight loss by bariatric and metabolic surgery results in a significant decrease in QTc interval and P-wave dispersion. The effects on atrial fibrillation are conflicting and not yet fully understood.