The Patient:  67-year-old man complaining of chest pain radiating to his jaw, 10/10. He is short of breath and diaphoretic. We do not know his BP, just that it was low.  The patient states “no past medical history – never hospitalized”. He thought himself to be very healthy.  He was given aspirin 325 mg and transported to a full-service cardiac hospital as a “cardiac alert”.

The ECG (from EMS): 

The rhythm is atrial fibrillation with a rapid ventricular response (about 134/min.). The QRS width is .118 seconds (118 ms).  The frontal plane axis is slightly to the left, but WNL. The R wave progression mostly normal, but V4 is incongruous.  V2 and V3 have a tall R wave, possibly representing a pathological Q on the posterior side.  There are ST CHANGES in every lead. ST elevation is noted in III, aVF, aVR, V5 and V6, representing ischemia in the inferior wall. There is ST depression in all other leads, indicating widespread subendocardial ischemia and/or acute reciprocal depression.  Interesting that Lead II would normally be elevated when III and aVF are, but aVR is elevated, causing reciprocal ST depression in Lead II.  So, Lead II looks almost normal.  

The pattern of ST elevation in aVR with widespread ST depression can indicate:

1)     Proximal occlusion of LCA

2)     Severe triple vessel disease

3)     Any condition that results in cardiogenic shock

Often, there is also STE in V1 in this situation, but V1 – V3 show signs of posterior MI, with definite ST depression and tall R waves in V2 and V3.

It is obvious that this patient’s condition is extremely dire, and he would earn a trip to the cath lab on symptoms alone in most places. An inexperienced observer might not recognize the importance of the ST elevations, since they are not large, but the pattern of elevation and the widespread ST depression is very alarming.

The Emergency Department:  The patient was prepared for transport to the cardiac cath lab, but suffered a storm of ventricular tachycardia and ventricular fibrillation. He was defibrillated multiple times and intubated.  He was given magnesium sulfate, amiodarone, esmolol, and bivalirudin.

The Cath Lab:  In the cath lab, the circumflex artery was found to be totally occluded. When a wire was introduced, circulation opened up, revealing an extensive collateral system from the circumflex to the area usually supplied by the RCA (inferior/posterior wall). The right coronary artery (RCA) was found to have chronic total occlusion (CTO), confirmed by the presence of a collateral system from the circumflex. The arteries show extensive disease. The patient was stabilized with an Impella (mini ventricular pump) placed due to cardiogenic shock.  The ECG shows how extensive the damage can be when coronary circulation is relying on one coronary artery system (LCA) to supply the entire heart, and that a large part of that supply (circ) is acutely occluded.

The Outcome:  The patient went to surgery for five-vessel coronary artery bypass graft.  He did well, and three days later he was awake, alert, having had all central lines, ventilator and ventricular pump removed.

This is a great teaching example emphasizing how important symptoms and presentation are in determining severity of condition. Another good teaching point is that the size of the ST elevation is not necessarily a determination of severity of cardiac damage. Not all OMI patients will present with a nice, neat ECG showing a pattern of one-vessel occlusion with large ST elevations. This is a reminder of the outcomes that are possible in a place that has well-trained EMS and the availability of nearby full-service cardiac hospitals.

Our thanks to Natalie Terrana, RN, EMT-P for contributing this valuable teaching case.  She happens to be a friend of the ECG Guru website since our beginnings, and is the one who came up with the name, ECG Guru!