EMS is called to the residence of a 66-year-old female complaining of chest discomfort. The patient is found sitting in a kitchen chair. She is alert and oriented but highly anxious and diaphoretic. She appears acutely ill.
Paramedics assess her vital signs.
- Respiratory rate: 18
- Pulse: 74
- NIBP: 102/63
- SpO2: 95
A 12-lead EKG is obtained.
Although this EKG meets the voltage criteria for left ventricular hypertrophy in the limb leads, it shows acute inferior STEMI.
ST-elevation is present in leads II, III and aVF along with reciprocal ST-depression in leads I and aVL. Remember that left ventricular hypertrophy is usually an anterior STEMI mimic.
A “Code STEMI” was called from the field. The patient was given four baby aspirin, a sublingual nitroglycerin spray and oxygen.
Less than four minutes later, the patient was in the back of the ambulance and another 12-lead EKG was captured.
As you can see, the EKG is now nondiagnostic for acute STEMI. This patient’s reperfusion could have been seriously delayed. But, because the paramedics obtained a 12-lead EKG with the first set of vital signs, the patient was taken rapidly to the cardiac catheterization lab, where an acute 99 percent occlusion of the right coronary artery (RCA) was identified and stented.
The patient’s door-to-balloon time was less than 60 minutes.
Too often, paramedics think of the 12-lead ECG EKG just one of the things to check off the list. “I need to place the patient on oxygen, I need to start an IV, I need to give baby aspirin, I need to give nitroglycerin, I need to get a 12-lead EKG …"
Early 12-lead EKG is critically important
In reality, early acquisition of a 12-lead EKG for all patients with signs and symptoms of ACS is critically important to the success of a prehospital 12-lead EKG program.
Why? Because the same drugs we give to restore balance between myocardial oxygen supply and demand can “clean up” or erase ischemic changes on the 12-lead EKG .
Sometimes the prehospital 12-lead EKG is the only evidence that a patient’s chest pain was cardiac in origin! Imagine if this patient never received a prehospital 12-lead EKG and the cardiac biomarkers came back negative.
A patient with a high-risk lesion might have been discharged home. It’s unlikely, but it could happen. What would you want for your mother or father?
Read next about the importance of performing serial ECGs.
