Generally the ECG check is accurate while taking medication, but the ECG check may be inaccurate if you are using drugs such as amiodarone and nifedipine. ECG is a clinical method used to monitor changes in the electrical activity of the heart, and most patients are accurate in checking ECG test while taking medications, such as Irbesartan, Benadryl, Hydrochlorothiazide, and so on. However, for some people taking drugs such as amiodarone, nifedipine, propranolol, digoxin, verapamil, atropine, etc., the ECG examination can be inaccurate due to the effect of the drug affecting the heart rate or rhythm. In addition to drugs affecting the accuracy of ECG, eating a lot before the test, strenuous exercise, prolonged sleep deprivation and mental stress can cause ECG abnormalities. ECG is a non-invasive test that will not affect the health of the body, so the examinee should adjust his/her mind and actively cooperate with the medical staff. It is recommended to consult a regular hospital to ensure the accuracy of the ECG results. If you have any special medication, you should inform your doctor before the ECG test.