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ECG -- February 2017


Case presentation

A 57 year old man complains of mid-sternal sharp chest pain radiating to his back and jaw. The pain started while he was watching a football game on television, approximately 2 hours prior to calling 911. The patient denies any medical history. However, his wife endorses a history of untreated hypertension.

Case presentation



What does this ECG show?

Rate 90 bpm
Rhythm Sinus vs Accelerated Junctional rhythm
ST Elevation >1mm in two or more contiguous leads? Yes
Which Leads? V2, V3, II, aVF
Reciprocal Changes? No
Other Abnormalities? PVC noted (see V4-V6) with wavy baseline


In the following diagrams, the green lines connecting adjacent P waves to T waves indicate the electrical baseline. ST elevations are shown in V2 and V3, representing an acute myocardial infarction (MI) in the anterior wall of the left ventricle.

Case presentation

ST elevations are more subtle in II and aVF, leads representing the inferior wall of the left ventricle. ST elevation is also noted in lead III, although it does not meet the >1mm criteria. While looking at lead II, one can also note that P waves are not reliably noted. While the rate argues for a sinus rhythm, this may alternatively represent an accelerated junctional rhythm. The choice between these two should not change management or additional interpretation of the ECG.

Case presentation

There were no obvious reciprocal changes on this ECG. Close examination of the ECG demonstrates an isolated PVC recorded on the ECG.  While not inherently dangerous, the presence of ectopy (abnormal beats) in the setting of cardiac ischemia should be monitored closely.  Acute MI may lead to a variety of conduction abnormalities, including heart blocks, ventricular tachycardia, or ventricular fibrillation.

Case presentation

The paramedic should be aware of this risk, and closely monitor the patient for early intervention if they should develop cardiac dysrhythmia.




How would you manage this patient?

The patient is having chest pain of a presumed cardiac cause, and the ECG shows STEMI. He should receive 162mg or 324mg PO aspirin, and may be given NTG 0.4mg SL every 5 minutes as needed for chest pain. The ECG should be transmitted to the STEMI Receiving Center for advance notification.  Frequent patient reassessments en route should include repeat vital signs, assessment of mental status, and monitoring for changes in rhythm. 


By Shira A. Schlesinger MD, MPH, Los Angeles County EMS Agency