Wellens Syndrome

The ST segment on an electrocardiogram (ECG) correlates to the plateau phase of ventricular repolarization; the T wave is associated with rapid ventricular repolarization in phase 3 of the cardiac action potential. Patients can develop repolarization (ST-T–wave) changes, called secondary changes, because of abnormal depolarization. Secondary ST-T–wave changes occur when the QRS complex is abnormal, such as in ventricular hypertrophy, bundle-branch blocks, or Wolff-Parkinson-White syndrome.^1,2  When an ST-T–wave abnormality is unrelated to a QRS abnormality, such as in injury or ischemia, it is considered a primary repolarization abnormality.¹  This column of ECG Challenges highlights the primary repolarization abnormality of T-wave inversion seen in Wellens syndrome.

De Zwaan et al³  found that T-wave inversion occurring in leads V₂ and V₃ (with or without other ST-T–wave changes in the other precordial leads) was associated with recent injury or ischemia caused by a left anterior descending...