How to recognize Wellens' Syndrome with a 12-lead EKG

Wellens' syndrome consists of two types of T wave changes in the anterior leads that are associated with critical LAD stenosis

Article updated July 27, 2017

You transport a 55-year-old woman, who complained of chest pains, to the emergency department. You continue to monitor her vital signs throughout your transport and she remains pain free, with warm and dry skin, and shows no respiratory distress.

You arrive at the hospital where, earlier in the day, you transported a reluctant 45-year-old man who developed retro-sternal chest pain and diaphoresis. He also reported a quick recovery from pain. You transfer care and report to the same staff and ER physician. You look over to room five, where your last patient was placed, and notice that the bed is empty and the room is being cleaned by housekeeping personnel. You ask the staff where the last patient went and you are told that he was taken straight up to the cath lab, but they have not been given an update yet. You track down the ER physician to pick his brain.

Understanding the 12-lead EKG changes

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

  • Basic: To recognize signs and symptoms of acute coronary syndrome, even in the asymptomatic patient, and to encourage delivery of all ACS patients to a cath lab facility.
  • Intermediate: To recognize and appropriately treat suspicious clinical presentations.
  • Advanced: To recognize the ECG patterns associated with Wellens' syndrome and to understand the close association with a proximal left anterior descending coronary artery lesion/stenosis and need for urgent coronary angiography.

Both of the patients in exhibit clinical symptoms and EKG changes symptomatic of acute coronary syndrome, which could be either the result or cause of  acute myocardial infarction. Both patients experienced chest pain or discomfort with some associated symptoms and both had similar past histories. This warranted initiation of treatment in the field and transport to a cath lab facility. 

Wellens' syndrome describes a recognized pattern of T wave changes or abnormalities that are associated with a critical, proximal left anterior descending coronary artery stenosis. Some references also call it LAD Coronary T wave Syndrome, again, reflecting the relationship between T wave changes and LAD pathology. 

Criteria for Wellen's syndrome that are applicable to the prehospital provider include:

  • T wave changes
  • History of anginal chest pain but symptom-free at time of evaluation and EKG acquisition
  • Lack of significant Q waves
  • Lack of significant ST segment deviation
  • Normal precordial R wave progression

Wellens' syndrome consists of two types of T wave changes in the anterior leads that are associated, although some say predictive, of a critical LAD stenosis. These patients are at a high risk for the development of an extensive anterior wall myocardial infarction, which can result in cardiogenic shock and death. 

Once Wellens' syndrome has been recognized, it is imperative to then begin urgent coronary angiography treatment. Stress imaging, such as those found with a treadmill test or stress echo, is unnecessary and may in fact hasten the condition of the patient by precipitating an intra-test myocardial infarction. 

The most common pattern attributed to Wellens' syndrome is a deeply inverted T wave in the anterior leads (mainly V2-V3, but may also involve V1 and V4, V5 and V6) as noted as “Type 1” in the sample complex below. Note that the second patient in this case exhibited this pattern.


The second, and less common type of T wave change is the biphasic T wave in the anterior leads (mainly V2-V3 but may also involve V1 and V4) as noted as “Type 2” in the sample. This pattern was seen in the first patient.

The normal T wave in the anterior leads (V2-V4) is upright with no portion dipping below the baseline. Clearly Type 1 T wave changes are abnormal, as they are deeply inverted below the baseline. The changes seen with the less common Type 2 T wave changes are more subtle. Looking at the first patient’s pattern, the terminal portion of the T wave in the anterior leads dips below the baseline and is considered biphasic. 

Here are the 12-lead EKGs for both patients for reference (click for larger image):

Patient 1 exhibiting Type 2 T wave changes


Patient 2 exhibiting Type 1 T wave changes

(Please note that there is a component of biphasic T wave, especially in V2, but draw your attention to the inverted T waves in V3 and V4 and V5)

According to Rhinehardt et. al (2002), the clinical and EKG criteria for Wellens' syndrome includes: 

  • Symmetric and deeply inverted T waves in leads V2, V3 and occasionally in leads V1, V4, V5 and V6 
  • Biphasic T wave in leads V2 and V3 
  • Isoelectric or minimally elevated (<1mm) ST segment 
  • No precordial Q waves 
  • History of angina 
  • Pattern present while pain free 
  • Normal or slightly elevated cardiac serum markers (not routinely measured pre-hospital) 

It should be noted that T wave inversions may be secondary to other causes, such as: acute coronary ischemia, pulmonary embolism, central nervous system catastrophe, persistent juvenile T wave pattern and digitalis effect.
Both of the patients had EMS called for because of anginal symptoms that were completely resolved by the time paramedics arrived. It was indeed prudent, based on clinical symptoms, to transport to the nearest cath lab facility. Additional information that could be gleaned from the EKG included the typical T wave changes seen with critical, proximal LAD stenosis.

Mattu, A. (2007). Tough EKG's. (

Rhinehardt, J., Brady, W., Perron, A., & Mattu, A. (2002) Electrocardiographic menifestations of Wellens' syndrome. American Journal of Emergency Medicine 2002; 20:638-643. 

Tandy, T., Bottomy, D. & Lewis, J. (1999). Wellens' syndrome. Annals of Emergency Medicine 1999;33:347-351. 

Zwaan, C., Bar, F. & Wellens, H. (1982). Characteristic electrocardiographic pattern indicating a critical stenosis high in the left anterior descending coronary artery in patients admitted because of impending myocardial infarction. American Heart Journal 1982;103: 730-736. 

Zwann, C., Bar, F., Janssen, J., Cheriex, E., Dassen, W., Brugada, P., Penn, O., & Wellens, H. (1989). Angiographic and clinical characteristics of patients with unstable angina showing an ECG pattern indicating critical narrowing of the proximal LAD coronary artery. American Heart Journal 1989;117:657-665.

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