EKG case: Sudden onset chest pain while exercising

What's your assessment and care for patient who has severe chest pain radiating to his left arm?

Article updated July 27, 2017 

You have just cleared the hospital after transporting your third diabetic patient of the day. Dispatch breaks the silence with a series of tones and the following message: "Medic 91, Engine 73, respond to 126 Main Street, the YMCA building, for a male with chest pain."

Your partner says to you, “Is this another routine chest pain?”

You turn onto Main Street and stop in front of the YMCA building behind a fire engine. You and your partner gather your equipment and head into the building.

The EKG Club experts created this case for these learning objectives: 

  • Basic: Differentiating between inferior, anterior, septal and lateral leads.
  • Intermediate: Identification of right ventricular infarct and the treatment modalities.
  • Advanced: Identification of the culprit artery in the STEMI patient.

Patient presentation: Man clutching his chest

You arrive at the scene to find the engine crew gathering the patient’s vital signs and performing an initial assessment. You form a general impression that the patient is a 40-year-old man who appears to be in a lot of distress.

The patient is on the floor and clutching his chest. He advises that he was playing walleyball about 10 minutes ago when the pain started. He has never experienced this type of pain in the past. He is also slightly short of breath.

Primary assessment:

The patient describes a sharp pain that radiates to his left arm. He is very anxious and diaphoretic. Nothing improves the pain or makes it worse. Initially, the patient refuses to chew and swallow four baby aspirin.

Patient's vital signs: 

Heart Rate: 76 bpm
Respirations: 20 rpm
Blood Pressure: 132/90 mm Hg
SpO2: 98 percent room air
Pain: 8/10

Past Medical History:

Family history of cardiac disease


No known drug allergies



Initial EKG (click for larger image):

You acquire a 12-lead EKG.


Above is the EKG acquired. The computed interpretation is:

HR 61
PRI 166ms
QRSd 98ms
QT/QTc 392/394ms
Paxis 16
QRSaxis 34
Taxis 77

It reads:
Normal sinus rhythm
Inferior infarct, possibly acute
**  **  ACUTE MI  **  **
Abnormal ECG

Remember to complete your own interpretation using the steps recommended by the EKG Club.

Initial patient treatment:

You place the patient on a cot and take him out to the ambulance for a rapid transport. The patient initially refuses, but eventually agrees, to chew and swallow four baby aspirin. You initiate an IV solution of 0.9% NaCl in the left AC TKO via a 16-gauge angiocath. A second IV line is also established in the patient's right arm. You do all of this while en route to the hospital.

The patient requests to be taken to the local (closest) hospital, which does not have cardiac intervention capabilities. 

You discuss your assessment and the 12-lead EKG findings with the patient and inform him that a more distant hospital, about 20 minutes away, can provide cardiac catheterization and has cardiologists on staff to treat him. You also describe the increased risk of death and a possible worsened outcome by delaying necessary interventions in a calm and professional manner. The patient quickly agrees and transport to the more distant hospital is underway. 

En route to the hospital, you perform a right-side EKG to acquire lead V4r. You acquire the following 12-lead EKG.

Second EKG (click for larger image):


The computed interpretation is:

HR 61
PRI 166ms
QRSd 92ms
QT/QTc 370/372ms
Paxis 38
QRSaxis 37
Taxis 77

It reads:
*** Poor data quality, interpretation may be adversely affected
Normal sinus rhythm
Inferior infarct, possibly acute
Anteriolateral infarct, age undetermined
**  **  ACUTE MI  **  **
Abnormal ECG

Right-side EKG acquisition

EMS providers should always consider obtaining a right-side EKG when the patient presents ST elevation in leads II, III, and/or aVF, which are the leads that look at the inferior wall of the heart. The standard 12-lead EKG does not measure the right ventricle, but it is frequently the site of myocardial infarctions.

Some studies suggest that 40 percent of patients suffering from inferior wall myocardial infarction also have right ventricle involvement. Special consideration must be given when treating these patients with nitroglycerin or if the patient is bradycardic. If your agency does not have protocols that address the treatment options for these patients, you should discuss this with your medical director.

You recognize the signs of right ventricular infarct and ST elevation in lead V4r and contact medical control for guidance on the management of this patient.

Consider these questions about the patient's condition and best course of treatment. 

  • What should you be concerned about?
  • Why has nitroglycerin not been administered yet?
  • Which hospital should you transport this patient to?
  • What is the prognosis for the patient?

Patient follow-up: Why it's important to identify right ventricular infarct

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