May I ask for your advice/comments please? The sponsor provided us (investigator site) a ECG machine of which ECG data is transferred electronically to the assigned company. At the same time, the machine prints the tracings to site for investigator to review.

- Do you consider if the transmissions are considered as the original source or the thermal paper tracings are.

- Because thermal paper is known to fade away over time, the sponsor requested site to make certified copies of ECG tracings. Could you advise if this is a standard procedure for ECG tracings?

Your advice would be very helpful. Thank you very much.