Wellens Syndrome Workup

The following laboratory studies may be indicated as adjunctive tests in patients with suspected coronary artery disease (CAD), acute coronary syndrome (ACS), and Wellens syndrome:

• Complete blood count (CBC) - To ensure that anemia is not precipitating the angina, red blood cell (RBC) transfusions may be necessary

• Basic metabolic profile - This includes electrolyte, blood urea nitrogen (BUN), creatinine, and glucose levels

• Typing and screening - These are indicated if immediate cardiac catheterization is planned

• D-dimer, international normalized ratio (INR), partial thromboplastin time (PTT) - These are ordered only as medically necessary

• Cardiac biomarkers - In Wellens syndrome, cardiac biomarkers can be falsely reassuring, in that they are typically normal or only minimally elevated; only 12% of patients with this syndrome have elevated cardiac biomarker levels, and these are always less than twice the upper limit of normal, in the absence of myocardial infarction (MI) ^[5]

Chest radiography should be performed to look for side effects of ischemia, such as pulmonary edema. In addition, this test should be performed to help exclude other possible causes of chest pain, such as thoracic aneurysm or dissection, pneumonia, and rib fracture.

Computed tomography (CT) of the chest is performed only as indicated to help rule out other causes of chest pain, such as aortic dissection or pulmonary embolus. The value of CT angiography of the chest in the evaluation of chest pain, CAD, and ACS is currently being investigated.

ECG should be performed on any patient with a complaint of chest pain if noncardiac causes cannot be diagnosed by other means, including physical examination. It may be helpful to perform ECG both while the pain is present and after the pain has resolved. The ECG changes seen in Wellens syndrome typically are manifested when the patient is pain-free but usually occur in the context of recent anginal chest pain.

In Wellens syndrome, the ECG pattern shows significant involvement of the T wave, with minimal ST-segment alteration. The ST segments themselves are usually isoelectric, but if they are abnormal, there will be less than 1 mm of elevation, with a high takeoff of the ST segment from the QRS complex. The characteristic ECG changes of this syndrome occur in the T-wave and occur in 2 forms.

The more common of the 2 forms, which occurs 76% of the time, is deep inversion of the T-wave segment in the precordial leads (see the images below). ^[6] The ST segment will be straight or concave and will pass into a deep negative T wave at an angle of 60°-90°. The T wave is symmetric. In Wellens syndrome, these changes generally occur in leads V₁ -V₄ but occasionally may also involve V₅ and V₆. V₁ is involved in approximately 66% of patients, and V₄ is involved nearly 75% of the time. ^[7]

This ECG represents a patient who came in to the emergency department with 8/10 chest pain. The patient had old right bundle-branch block (RBBB) and left ventricular hypertrophy (LVH), and this compared similarly to his previous ECGs.

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Classic Wellens syndrome T-wave changes. ECG was repeated on a patient who came in to the emergency department with 8/10 chest pain after becoming pain free secondary to medications. Notice the deep T waves in V3-V5 and slight biphasic T wave in V6 in this chest pain– free ECG. The patient had negative cardiac enzyme levels and later had a stent placed in the proximal left anterior descending (LAD) artery.

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The less common of the 2 forms of Wellens syndrome, which occurs in 24% of patients, consists of biphasic T waves (see the images below), most commonly in leads V₂ and V₃ but also, on occasion, in leads V₁ through V₅ or even V₆. ^[5]

A 57-year-old with 4/10 pressurelike chest pain. Improvement with treatment by EMS. The patient had this ECG on arrival. Notice perhaps the beginning of a small biphasic T wave in V2.

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Pain-free ECG of a 57-year-old patient who presented with 4/10 pressurelike chest pain. Notice after the patient was treated with medications and pain subsided, the ECG shows T-wave inversion in V2 and biphasic T waves in V3-V5. This more closely resembles the less common presentation of Wellens syndrome with a biphasic T-wave pattern. This patient had a cardiac catheterization that showed a subtotal occlusion of the proximal left anterior descending (LAD) artery, which was stented, and the patient did well.

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The characteristic pattern classically presents only during chest pain–free periods. Noticing this pattern is crucial because it is a sign of LAD disease. This association underscores the importance of serial ECGs and a pain-free ECG on patients with unstable angina. Because the LAD supplies the anterior myocardium, failure to recognize this pattern can result in anterior wall myocardial infarction (MI), significant left ventricular dysfunction, or death.

Reperfusion of the posterior wall following posterior MI leads to a larger T-wave amplitude in the right precordial leads and an even higher T-wave amplitude in leads V₂ and V₃. ^[8]

Angiography has demonstrated that 100% of patients with Wellens syndrome will have 50% or greater stenosis of the proximal LAD. ^[5] More specifically, 83% will have the lesion proximal to the second septal perforator. ^[7]

Stress testing is generally not indicated in patients with this ECG presentation, because it places them at risk for acute anterior wall MI. Ideally, therefore, these patients would bypass stress testing and undergo urgent angiography to determine the extent of disease and potentially provide information about the need for percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), or medical management. ^{[6, 9]} If provocative testing is determined to be necessary, it should be done cautiously and only in close conjunction with a cardiologist. ^{[6, 10]}