Date Published

February 13, 2017

Updated For

ALS PCS Version ALS PCS Version 5.2


Question: In Elgin county we have been having trouble with our defibs spitting out 'noisy data' warnings on our 12 lead ECG's lately which has prompted conversation with crews about the STEMI protocol. Though the protocol clearly states that LP15 ECG software interpretation meets ***MEETS ST ELEVATION... some crews are saying that due to this issue with noisy data, we are able to interpret the ECG on our own and determine if it meets our criteria based on the >1 mm/or the >2mm ST elevation criteria. Your thoughts? Should we patch the cardiologist? Should we transport to nearest ED due to software not recognizing due to noisy data?


This is an interesting question. I direct you to the LP15 Operating Manual pages 4-17, 4-18, 4-22, and 4-23. I will quote the relevant pages 4-17 and 4-18 from the manual:

ECG Override: 

If the monitor detects signal noise while acquiring data (such as patient motion or a disconnected electrode), the screen displays the message: NOISY DATA! PRESS 12-LEAD TO ACCEPT. The message remains and 12-lead ECG acquisition is interrupted until noise is eliminated. Take appropriate action to eliminate the signal noise. This message remains as long as signal noise is detected. When signal noise is eliminated, the monitor resumes acquiring data. To override the message and acquire the 12-lead ECG in spite of the signal noise, press 12-LEAD again. The 12-lead ECG will be acquired and printed with no interpretive statements. Any 12-lead ECG report acquired in this way is annotated with the following statement: ECG OVERRIDE: DATA QUALITY PROHIBITS INTERPRETATION. If the signal noise persists for longer than 30 seconds, 12-lead ECG acquisition stops. The screen displays EXCESSIVE NOISE€“12-LEAD CANCELLED. You must then press 12-LEAD to restart 12-lead ECG acquisition.

Note: If 12-LEAD is pressed immediately after ECG electrodes are applied, the message NOISY DATA may occur. This message is due to the temporary instability between the electrode gel and the patients skin that is not viewable on the ECG monitor screen, but is detected as noisy data. In general, it is best to wait at least 30 seconds after applying the last electrode before pressing the 12-LEAD button, to allow for electrode/skin stabilization. Also, good skin preparation shortens the stabilization time.

Pages 4-22 and 4-23 gives a list of possible causes for the noisy data warning and what to do about trying to fix them.

If you are still unable to obtain a clean 12 lead ECG that does not contain the warnings as listed above, then it is reasonable to go to the closest ED and have the emergency physician sort out the diagnosis before undertaking a STEMI bypass.



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