Other underlying risk factors or indirect, non‐hERG mechanisms could have contributed to the QT prolongation cases in LEV‐treated patients, although with limited evidence, such as hypertension, bradycardia, concomitant use of long QT prolonging drugs, congenital heart disease, myocardial infarction, hypokalemia, renal failure and hypothyroidism. This evidence concerns the gene KCNH2 and congenital heart disease.