Can this substitue the traditional ECG?

AliveCor does not guarantee that you are not experiencing an arrhythmia or other health conditions with any ECG result, including normal. You should notify your physician for possible changes in your health. Use this device to record heart rate and heart rhythm only. DO NOT use to diagnose heart-related conditions. DO NOT use to self-diagnose heart related conditions. Consult with your physician before making any medical decision, including altering your use of any drug or treatment."