Background and aims: Recent studies have evaluated the relationship associating non-alcoholic fatty liver disease (NAFLD) with several electrocardiogram (ECG) findings, but the results have been inconsistent. The aim of this systematic review is to assess the association between NAFLD with ECG modifications.
Methods: We conducted a systematic search on PubMed with predefined keywords identifying observational studies published till 22 February 2019 with NAFLD diagnosed either by biopsy, imaging, surrogate markers or ICD code and ECG findings by either a standard ECG, 24-hour Holter ECG or ICD code. Quality assessment was performed using the quality assessment tools from the National Heart, Lung, and Blood Institute.
Results: A total of 20 observational studies (1 case-control, 4 cohort, 15 cross-sectional studies, 401,745 individuals) were included. Twelve studies evaluated cardiac arrhythmias in NAFLD subjects, out of which 10 evaluated atrial fibrillation (AF). Although results were inconsistent, most studies rated as "good" demonstrated that hepatic steatosis was independently associated with an increased risk for prevalent AF in NAFLD patients. Diabetic patients with NAFLD were associated with an increased risk of ventricular arrhythmias in only one study rated as "good". Two studies rated as "good" demonstrated that hepatic steatosis was associated with a prolonged QTc interval. Four studies supported the association between cardiac conduction abnormalities and NAFLD, out of which two were rated as "good". Two studies assessed ECG modifications of ischemic heart disease (IHD), but only one having a "good" rating confirmed this independent association.
Conclusions: Studies of high quality and with low risk of bias demonstrated that NAFLD is independently associated with AF, a prolonged QTc interval, bundle branch and atrioventricular blocks. Diabetic patients with NAFLD present an increased risk for developing ventricular arrhythmias.