"Watson, we have been assigned a case...appears it involves some angina pectoralis."
"Another? That's the third one this week Holmes."
"I'm afraid so ol' chap, I do wonder what the culprit will be..."
Watson and Holmes prepared for the call while navigating the switchback roads. They arrived at a quaint home to find the patient being investigated thoroughly by Inspectors Clouseau and Cato.
"Good day, inspectors. Facts of the case?"
"Watson and Holmes, good day! However, not so much for this fellow." Holmes and Watson noticed a look of great concern on their fellow inspector.
Facts of the case:
- chest pain upon waking and visiting the water closet, onset 1h ago
- "pressure" in his chest
- substernal pain that radiates to his jaw and down his left arm
- 10/10 pain
Watson had just finished helping the patient to the stretcher. "Holmes, he is quite pale and profusely diaphoretic, with a bit of nausea."
"Watson, obtain a 12-lead, good sir. Cato can you get some history from the madam? We have clear lung sounds upon auscultation, skin is pale and cool, radial pulses are regular, bradycardic, and a little weak."
Inspector Clouseau obtained the following vitals: HR 48, RR 22, BP 92/48, SpO2 96% on RA. The sound of a printer is heard, and the 12-lead is revealed:
"Oh my...very peculiar. Watson! Apply the defibrillator pads."
The patient was moved to the ambulance with haste as Holmes obtained the patient's history from Cato. "He has a history of hypertension, high cholesterol, and apparently a blood clot in his leg a year ago that he no longer has to take blood thinners for."
While enroute to the hospital Holmes transmitted the 12 lead and activated a STEMI alert. Clouseau administered aspirin and started an IV. The patient was also administered atropine, a fluid bolus, and heparin. They arrived at the hospital and transferred care to the awaiting team of providers.
Patient Outcome: The ol' chap survived! But not without experiencing two episodes of ventricular tachycardia and one of ventricular fibrillation treated successfully with defibrillation. He went to the cath lab and received a stent and ultimately survived his myocardial infarction.
12-Lead Discussion
If looking at this EKG you find yourself saying "I don't see the MI" that is okay. This EKG is what we call a STEMI equivalent; meaning it does not meet STEMI criteria but is associated (thru outcome collection and research) with high certainty of being an active myocardial infarction.
In leads V1-V4 we have tall, broad (fat), and symmetric T waves which in some leads are taller than the QRS complex. Hence, they are called "hyperacute T waves." This is the REAL focus of this blog. My goal is to give you some basic knowledge that you can apply as you practice recognizing these hyperacute T waves.
Normally T waves are asymmetric, less broad, and not tall in comparison to the QRS complex. I highly recommend getting familiar with what a normal 12-lead EKG is supposed to look like; this is extremely important in identifying abnormal intervals and complexes in each lead view. For example: it is normal to have an inverted T wave in lead aVR, where upright T waves in lead V1 are abnormal. Knowing this is going to take you to another level of EKG interpretation!
Hyperacute T Waves
I want to start with this: EVERY EKG NEEDS A STORY!
Our assessment findings, patient symptoms, and history gathering all help with interpreting an EKG. Each bit of information we gather can be a clue to help us narrow our differential. We keep this in mind when interpreting an EKG. What do i mean? Say we have a patient in DKA, or maybe that has missed a dialysis appointment and our EKG shows tall, peaked, and narrow T waves. This is hyperkalemia not hyperacute T waves.
Hyperacute T waves are commonly defined as: tall (compared to the QRS), broad (fat), and symmetric.
However, Dr. Smith will tell you: "There is no formal, universal definition of what constitutes a hyperacute T-wave...Hyperacute T-waves are fatter than normal T-waves and usually more symmetric (these characteristics increase the area under the STT as well). Hyperacute T-waves are sometimes so impressive that they are diagnostic no matter the situation. Other times, you can only diagnose hyperacute T-waves by comparing the current questionable T-waves with a prior ECG." (2018, Meyers & Smith).
We are at a slight disadvantage in the prehospital setting since we have no baseline EKG to compare to. With practice we can identify the obvious hyperacute T waves, and for the more questionable we can transmit the EKG. Remember, one of the earliest signs of a myocardial infarction is a hyperacute T wave. Serial EKGs may result in capturing active changes in the ST segment that can seal the diagnosis.
Two Examples of Hyperacute T Waves
65 year old patient with chest pain and clammy (Dr. Smith's ECG Blog, 2018)
Inferior Hyperacute T Waves (Dr. Smith's ECG Blog, 2016)
The more cases we review the better our recognition will be. That really is the key here. We can talk about it all day, but not until we see a significant volume of EKG cases can we TRULY become competent and confident. Luckily, we can find cases like the above on several websites for free! A paramedic can become just as proficient as a physician with just a little elbow grease and practice. That is no knock on our physicians just a reality of EKG interpretation you get out of it what you put in.
De Winter T Wave
I want to briefly mention this type of hyperacute T wave, the De Winter T Wave.
Per LITFL (2022, Buttner & Burns), this is De Winter criteria:
"- Tall, prominent, symmetrical T waves in the precordial leads
- Upsloping ST segment depression > 1mm at the j point in the precordial leads
- Absence of ST elevation in the precordial leads
- Reciprocal ST segment elevation (0.5mm – 1mm) in aVR
- Typical STEMI morphology may precede or follow the De Winter pattern."
(Life in the Fast Lane, 2022)
Wrapping It Up
Some studies report up to 25-30% of patients experiencing an MI will not meet STEMI criteria, but there are other criteria we can utilize. Hyperacute T wave is one of the several STEMI equivalents and is a sign of acute myocardial infarction. Change is a constant in medicine and in 2022 the American College of Cardiology changed its recommendations for immediate PCI, which now includes STEMI equivalents:
2022 ACC Expert Consensus Decision Pathway on the Evaluation and Disposition of Acute Chest Pain in the Emergency Department
2022 ACC Expert Consensus Decision Pathway on the Evaluation and Disposition of Acute Chest Pain in the Emergency Department
This is an exciting change to see. Keep Learning, Keep Growing, And Stay Safe!
References:
R Buttner and E Burns. 2022. De Winter T Wave. Life in the Fast Lane.
P Meyers and S Smith. 2018. "Are these hyperacute T-waves?" - what is your recommendation for the team in these two cases? Dr. Smith's ECG Blog.
Writing Committee et al. “2022 ACC Expert Consensus Decision Pathway on the Evaluation and Disposition of Acute Chest Pain in the Emergency Department: A Report of the American College of Cardiology Solution Set Oversight Committee.” Journal of the American College of Cardiology vol. 80,20 (2022): 1925-1960. doi:10.1016/j.jacc.2022.08.750
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