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. Here, KCNH2 is linked to hypothyroidism.