Prehospital ECGs Featured on Amal Mattu's ECG Case of the Week!

What happens when the computer calls, "Pericarditis?" Do you defer to LifeNet when encountering cases such as, "Abnormal ECG- Unconfirmed?" Watch this video to learn more about PR depression and how to differentiate pericarditis (not so bad) from STEMI (a bit more terrible). Watch, listen, save a life- and transmit those 12 leads!


Dr Mattu's ECG Case of the Week: Pericarditis?

The Power of the 12th Lead

EMS responds to the home of a 70 yo female patient. She reports severe, left-sided chest pain and mild shortness of breath.  Her skin is warm and dry.  Her abdomen is soft and non-tender.  She denies any medical history.

Vital signs:
BP: 142/76
P: 75
R: 18

Sp02: 98%

12 Lead ECG:

12 Lead ECG Interpretation and Discussion:

There is a baseline sinus rhythm. The rate is approximately 75 beats per minute.

The ECG also reveals left anterior fascicle block as noted by the rS pattern in leads II, III, aVF, and Rs pattern in leads I and aVL.

There is left axis deviation as demonstrated by the predominantly positive QRS complex in lead I, and predominantly negative QRS complex in lead aVF.

There is ST segment elevation in leads aVR and V1. In addition, ST segment changes (flat, depressed, or T wave inversion) are present in essentially every other lead (reciprocal changes).  Simultaneous ST segment elevation in leads aVR and V1 may predict left main coronary artery, or left anterior descending artery occlusion, and is considered to be a STEMI equivalent.  Patients who present with ST segment elevation in leads aVR and V1 should be transported to a facility capable of performing cardiac angioplasty.

Take-Home Points
Simultaneous ST segment elevation in leads aVR and V1 predicts LMCA or LAD occlusion
Patients should be transported to a cardiac intervention center and treated the same as STEMI

Well, I didn't see anything in the rhythm strip...

Case Description


Medics respond to the report of a 66 yo male with nausea, chest pain, and chest pressure radiating to the left arm. The patient appears well. Chest discomfort started 2 hours prior to EMS arrival. The patient's vital signs are as follows: BP: 168/100, P: 72, R: 60/regular. Sp02: 96% on RA. Physical examination is unremarkable. The patient is loaded for transport, and the paramedics consider aspirin and nitrates. A 12 lead ECG is obtained


12 lead ECG

12 Lead ECG Interpretation and Discussion 

The rhytm is sinus in origin, and there does not appear to be any ectopic beats. ST segments are upright with the exception of expected T wave inversion in lead aVR. Careful scrutiny of the inferior leads reveals subtle ST segment elevation of approximately 1 mm. ST segments should be measured at the "J" point, and there is just about 1 mm / 1 box of elevation in the inferior leads. Further substantiating the findings of ischemia are the ST segment elevations present in leads V2-V5. The ST segments takes on an almost horizontal appearance in V5 and the R wave progression is preserved. Reciprocal change in the form of ST segment flattening and depression appears in leads I and aVL. When deciding if any one ECG represents ischemic patterns look for (1 ) anatomic distribution of abnormal findings and (2) reciprocal changes. This ECG features both of these findings. This patient was transported for urgent PCI; I do not have angiographic findings available. The ST elevation in the limb leads is not all that impressive. It is easy to imagine that placing this particular patient "on the monitor" would interfere with the recognition of concerning ST-T changes in the precordial leads. 

Closer look at ST segment ugliness

12 Lead Interpretation

Sinus rhythm, rate of 60, widespread ST segment elevation in the inferior and anterior-lateral leads concerning for acute ischemia.

Pearls

• If there is ANY suspicion for coronary ischemia or cardiac-related chest pain, perform a complete 12 lead
• The presence of recipocal change makes the diagnosis of ischemia more likely
• Territorial ST-T changes (anterior, lateral, inferior) are similarly concerning for ischemia

Thoughts on another acute process that might produce widespread, diffuse STE? 

From the venerable and informative blog, "EMS12LEAD.com"

Here's an interesting case that addresses the concepts of (1) typical ST elevation / ST morphology and (2) infarct territory. The case is an excellent reminder about how EMS providers and emergency clinicians must never let their guard down and pay attention to the history of present illness! This particular "44 yo male [with] chest tightness" had me at, "hello." Check out the case- and the EMS12LEAD blog- here:

Snapshot case: 44 yo male- chest tightness

There's STE in V1 !

EMS responds to the report of a 77 year old male with chest pain. The patient is hypertensive, alert, and hemodynamically stable. Aspirin and nitroglycerin are administered per treatment protocol. A 12 lead ECG is obtained, and the paramedic asks about transport to the closest hospital versus a facility capable of percutaneous coronary intervention...


12 lead ECG



12 lead ECG Discussion

There is a baseline sinus rhythm. The rhythm is regular. Close scrutiny of lead II and V1 reveals the presence of p waves. The ST segments are upright in most leads with the exception of aVR. The QRS duration is slightly prolonged consistent with an interventricular conduction delay. The (1) positively deflected QRS in lead V1 and the (2) lengthened QRS duration suggests the presence of a RIGHT bundle branch block. There is a subtle slurred l S wave in V6 which further corroborates the diagnosis of a right bundle branch block.

The Slurred S Wave

12 lead ECG Interpretation

Sinus rhythm, right bundle branch block, rate of approx 80 beats/min.

Case resolution

The patient was transported to a local facility. Serial ECGs remained unchanged and cardiac enzymes were normal. The patient was discharged to home following an overnight hospital stay and a cardiac stress test.