An ECG Case: The importance of repeating an ECG in the first 2 hours… even if a patient is chest pain-free.
Patient: A 53-year old male smoker, experienced transient central chest pain at 13:05, lasting 15 minutes. He called 9-1-1 at 13:15.
When EMS arrived at 13:24 the pain had resolved. Initial blood pressure was 110/70 mmHg and HR 72 bpm.
The first ECG performed by EMS at 13:32 is below:
EMS thought the tracing was normal and contacted the CODE STEMI doctor on call, who agreed. Nonetheless, because of the concerning symptoms the patient was taken to the St. Boniface Hospital emergency department.
Second ECG was done at 14:00. It remained unchanged and normal.
The vital signs remained normal, as did physical examination. The patient remained free of chest pain or other symptoms. Initial high sensitivity troponin T drawn at 13:58 was 4 ng/L (normal below 14ng/L)
As per routine standing orders, a repeat ECG and troponin was done in 2 hours at 16:00. The patient remained asymptomatic. The troponin returned at 10 ng/L.
The third ECG is below:
There are new biphasic T waves in the inferior leads, 2, 3 aVF and anteroseptal leads V2-V3. The T waves are now negative in the anterior leads V3-6 and as well as lateral leads I and aVL.
The next morning a coronary angiogram demonstrated 99% stenosis of the proximal left anterior descending (LAD) artery. This was treated with 1 drug eluting stent (DES) with a good result.
(Before left, after right)
Image from: https://en.wikipedia.org/wiki/Wellens%27_syndrome#/media/File:Wellens'_Warning.gif
Key takeaways:
This case demonstrates the importance of serial ECGs. Despite the patient having 2 normal ECGs, initial normal troponin and remaining free of recurrent chest pain the T wave abnormalities appeared. These ECG changes are typical of Wellens Syndrome. This ACS presentation is almost always associated with critical disease of the left anterior descending (LAD) coronary artery. Despite remaining in the “normal” range, the small rise of high sensitivity troponin warrants further observation. Clinical judgment and repeat ECG is crucial.
Patients with Wellens syndrome require hospital admission and early coronary angiography and revascularization, usually with coronary stent to the LAD or coronary artery bypass graft surgery, if more appropriate. In the absence of coronary intervention or bypass, most patients with Wellens syndrome will develop anterior MI.
