Repeat EKG's

Repeat EKG's


STEMI takes time to appear, if at all

Dr Jordan Singer

Case summary:


An ALS crew responded to a 50s man who called for difficulty breathing.  First responders had arrived on scene first and were obtaining a 12-lead while the transporting crew arrived.  The patient was clutching his chest stating that he could not breath, his chest hurt and he felt like he needed to vomit.  Crew noted him to be diaphoretic and his skin was ashen.   Initial 12-lead was normal sinus rhythm without ST elevations or depressions.  Vitals were obtained prior to extrication.


Vitals: BP 144/86,  HR 98,  RR 18,  Sat 98%,  ETCO2 37 mmHg


The crew administered aspirin and nitro due to concern that his pain was cardiac in nature.  The crew then extricated and prepared for transport.  Once in the rig, they obtained a repeat EKG which showed ST elevation in II, III and aVF with reciprocal depressions.  This was consistent with an inferior wall MI so they called the receiving hospital to activate the cath lab and administered anticoagulation per local protocol.  The patient remained hemodynamically stable while in route and did very well in the hospital. 


Highlights of the case:

STEMI’s take time to appear on an EKG

The reason that we care so much about STEMI (ST Elevation Myocardial Infarction) pattern on an EKG is that it is indicative of an acute coronary vessel occlusion which is causing an MI.  These patients need immediate opening of this blood vessel to treat their condition.  However, this STEMI pattern takes time to appear on an EKG.  If a patient activates EMS right after the pain begins, it is possible that they are having a blocked coronary even though the EKG does not show STEMI.  In patients where we are very concerned that they are having a blocked coronary, but the STEMI has not appeared on the EKG, we should repeat the 12-lead every 5-15 minutes to catch the appearance of STEMI as early as possible.  If we can make that diagnosis earlier, we can activate the cath lab earlier so that the patient gets definitive care as soon as possible.  Patients where we should be very worried are patients who are diaphoretic, ashen and who have the right risk factors.  In reality, if you are ever asking yourself if an EKG could be needed or needed a second time, the answer should always be yes!  This crew was worried about an MI, and for this reason they repeated the 12-lead and diagnosed the STEMI as early as possible.