Answer: This is a terrific question. Part of the confusion surrounding ECG acquisition is that in the previous set of directives, there was a specific 12 lead Acquisition Protocol which specified when an ECG should be considered.
The indications were:
1. An alert patient experiencing chest pain or other symptoms consistent with that caused by cardiac ischemia OR experiencing his or her typical angina/MI pain.
2. A patient whose 3 or 5 lead ECG shows a rhythm which is difficult to interpret
In the most recent set of directives, there is no longer a dedicated 12-lead ECG protocol, however consideration for 12-lead acquisition (if available) is mentioned in a number of areas including the cardiac ischemia directive.
To be absolutely clear, a 12-lead ECG should be performed where indicated in the new Advanced Patient Care Standards. This would be considered the minimum, and for those searching for a concrete answer as to when to acquire a 12-lead ECG, you can stop reading now because that is as clear as we can get on this topic.
With that said the SWORBHP Medical Council would suggest that the 12-lead ECG provides valuable information to receiving ED physicians and ultimately provides benefit to the patient in a variety of other clinical situations. While we would not advocate acquiring a 12-lead ECG on anyone and everything, we do believe that a more liberal use of the 12-lead ECG is reasonable as long as it can be acquired in a reasonable time frame (not prolonging scene time) and the patient is hemodynamically stable.
We cannot create an exhaustive list of these clinical situations, nor would the SWORBHP Professional Standards cite a paramedic for acquiring or not acquiring a 12-lead as long as the above criteria are met (short scene time and stable patient).
Clinical situations we would consider a 12-lead ECG reasonable in an otherwise stable patient would include (again not an exhaustive list, paramedics should use judgment): suspected OD, tachycardia, bradycardia, suspected block or arrhythmia, syncope (not just pregnant patients), suspected electrolyte disorders (example dialysis patient).
Remember, the 12-lead ECG is a tool, and another “piece of the puzzle”. It should not change a paramedic’s management in isolation if normal or abnormal outside of areas where a STEMI bypass protocol is in place. For example, if a patient does not have chest pain but for some reason a 12-lead is acquired and it is abnormal, this does not mean the patient is having ischemia and requires ASA or NTG. Alternatively, if the patient is having chest pain and the 12-lead is normal, this does not eliminate the possibility that the chest pain is ischemic and if the conditions are met by the Cardiac Ischemia Directive, then ASA and NTG should be considered.
For more information about 12-lead ECG, please see the WEBINAR on 12-Lead ECG which was presented by Dr. Davis and Dr. Lewell in November 2011 here:
http://www.lhsc.on.ca/About_Us/Base_Hospital_Program/Education/Paramedic_Rounds.htm