Date Published

March 21, 2024

Updated For

ALS PCS Version ALS PCS Version 5.2


In the companion document under the medical cardiac arrest directive it lists reasons for early transport. Under here it lists thrombosis (pulmonary and coronary). So to my understanding, if we have a VSA we believe to be caused by a coronary thrombosis (a STEMI) we are to do 1 analyze?

In the past it has been said that we are to treat a suspected MI VSA as a medical cardiac arrest and run the entire protocol on scene. Can you please clarify?


Thank you for your thoughtful question. To elaborate on the topic for other readers, the OBHG Companion Document states, “To expand on the consideration of other known reversible cause of arrest not addressed could be” and lists the H’s and T’s from ACLS. This list of “H’s and T’s” is an approach to think of potential reversible causes to consider in the setting of arrest that may have a potential treatment not available in the prehospital setting. However, it does not mean that you would consider very early transport for all of these on the list. For example, if you suspect hypoxia as the cause for arrest, you would provide supplemental oxygen and airway management strategies prior to initiating transport,

There are a couple of things to unpack here regarding clinical suspicion of STEMI or MI in a VSA patient:

If you arrive and the patient is already VSA with intra-arrest rhythm strip showing STEMI, it does not necessarily mean that they had a STEMI that caused the arrest. Ischemia from arrest itself can cause ST elevation on ECG. This patient should be managed via your typical Cardiac Arrest Medical Directive and would need more clinical history or suspicion than just the ECG for consideration of STEMI as the cause of arrest. Limited history and diagnostics make it very difficult to discern causes of cardiac arrest in the prehospital setting and many causes of cardiac arrest have similar preceding signs and symptoms.

However, should you have a patient who has been diagnosed with STEMI prior to arresting, this is a patient who you would consider leaving after a MINIMUM of 1 analysis. . The exception to this would be if a pre-arrest STEMI patient were in refractory VF or pulseless VT: In this scenario you would follow the Medical Cardiac Arrest Medical Directive for the refractory VT/pulseless VT treatment, leaving after 3 defibrillation attempts (or per DSED protocol where authorized). In this situation it would be advantageous to try to abort the non-perfusing ventricular dysrhythmia. Remember to make sure you have optimized your resuscitation care (high quality CPR, airway management) prior to departing scene.

The key to considering very early transport is having a very high suspicion of the cause for arrest being reversible and not able to be managed in the prehospital setting.

Regarding where to transfer to for a suspected STEMI patient who has arrested: Please follow your local service hospital destination agreements and practices regarding calling the cardiac interventionist for consideration of bypass to the cath lab despite the patient being in cardiac arrest.



Cardiac Arrest, Cardiac Ischemia, Hs and Ts, Reversible cause, STEMI, Thrombosis, very early transport

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