Early repolarization
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: early repolarization pattern; early repol; early repol variant
Overview
Early repolarization is defined as notching or slurring of the morphology of the terminal QRS complex or J-point elevation >0.1 mV above baseline in at least 2 lateral or inferior leads.[1] Early repolarization is a normal ECG variant that is most commonly seen in young males. It can be confused with ST elevation MI and pericarditis.
Natural History, Complications and Prognosis
A case control study of 120 post MI patients with implantable cardioverter-cefibrillators (ICDs) demonstrated that early repolarization was more frequently observed among patients with documented episodes of VT/VF (32% vs. 8%, p=0.005). The leads demonstrating early repolarization were more often the inferior leads (23% vs. 8%, p=0.03). A trend was observed for the lateral leads (V4-V6) as well (12% vs. 3%, p=0.11). In contrast, leads I and aVL were not commonly involved (3% vs. 0%). The morphology of the ST segment was critical and a notch in the ST segment was observed more frequently among patients with VT/VF (28% vs. 7%, p=0.008). In contrast, J-point elevation and slurring of the ST segment surprisingly were not associated with ventricular arrhythmias.[2]
Diagnosis
Differentiating Early Repolarization From Other Disorders
Early repolariztion must be differentiated from other causes of ST elevation including ST elevation MI and pericarditis.
Vagal Maneuvers and Bradycardia Exacerbate Early Repolarization
- Early repolarization is exacerbated by bradycardia, and carotid sinus massage or vagal maneuvers may also exacerbate the variant.
Early Repolarization is Characterized by a Notch at the J Point
- In the figure shown below, the red arrow points to a characteristic notch which is present at the J point in early repolarization:
Height of the J Point
Only lead V6 is used to distinguish between early repolarization and pericarditis. As shown in the figure below, if A/B > 25%, suspect pericarditis. If A/B < 25%, suspect early repolarization.
Electorcardiographic Examples
Shown below is an example of benign early repolarization with J point elevation, concave shaped up-sloping ST segment, and prominent T waves in the inferior and lateral leads:
Shown below is an example of early repolarization with notching of the J point in the lateral leads:
