Ambulances & Vehicle Ops, Cardiac & Resuscitation, Operations, Patient Care

The Need for 12-Lead: A vague chief complaint turns out to be something more

Issue 7 and Volume 33.

At 3:30 a.m., a crew was dispatched to the hotel room of a 54-year-old male. On arrival, the patient weighing approximately 160 lbs. appeared stable and complained only of “throat pain.” After providing a pertinent history, he explained that he had been a pack-a-day smoker for 10 years. Further, he had just traveled to the U.S. from London on a 12-hour flight.

The non-radiating throat pain, which he described as being a six out of 10, began during a layover. Despite resting for several hours after landing, the pain persisted, prompting the patient’s 9-1-1 call.

Figure 1: The patient’s ECG from lead II, indicating a normal sinus rhythm

His vitals all appeared to be within normal limits, except his skin, which was cool, pale and diaphoretic. In fact, the lead-II reading on his ECG was a normal sinus rhythm. (See Figure 1.) One paramedic felt a 12-lead was warranted due to the unclear chief complaint. However, a senior paramedic on scene felt a 12-lead was not indicated. So, the crew transported the patient to an emergency department (ED) with no STEMI center.

Approximately one hour later, the ED staff performed a 12-lead ECG; it read, “***Acute Inferior MI.” (See Figure 2.)

Figure 2: The patient’s 12-lead ECG showing acute inferior myocardial infarction

The patient had quickly deteriorated, and the receiving facility was unable to provide the necessary cardiac intervention. The crew was dispatched to the ED to land an air ambulance and transfer him to the appropriate facility. After a follow-up, the cardiologist found the patient had massive infarcts throughout his heart. The patient succumbed to cardiogenic shock three days after ICU admission.

Discussion

This case demonstrates the importance of 12-lead ECGs, STEMI recognition and rapid door-to-needle time for proper intervention and recovery whenever a provider thinks the incident may be cardiac-related.

The current guidelines from the American Heart Association and American College of Cardiology emphasize the critical role EMS can play in the early detection of acute myocardial infarction (AMI). The guidelines strongly urge EMS providers to routinely perform and evaluate ECGs on chest pain patients suspected to have a STEMI.

It’s widely believed that EMS has only three ways of definitively detecting AMI by ECG (ST elevation of 1 mm or more in two or more contiguous leads, reciprocal ST depression and Q waves). In fact, there are two additional indicators: changes compared with earlier ECGs and changes seen from one new ECG to the next.

Considering the increasing quality of 12-lead AMI diagnostic methods, the value of a pre-arrival alert and the speed with which 12-leads can be performed en route, there’s no good reason not to do one when you suspect an AMI.

References

1. Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction. J Am Coll Cardiol. 2004;44(3):E1-E211.

2. Slovis CM. The importance of prehospital ECGs. JEMS. 2006;31(7):S5-S6.