Early Repolarization: Benign or Malignant?

Related video: J wave syndrome: • J Wave Syndrome
Early repolarization - benign or malignant?
Early repolarization syndrome or pattern in the ECG has been thought to be a benign normal variant pattern for a long time.
But some recent articles have linked it with idiopathic ventricular fibrillation. Others have found it to be linked with cardiac channelopathies like Brugada syndrome with a malignant course
It has been proposed that the early repolarization pattern if found in inferolateral leads have a more sinister connotation than in the classical anterolateral leads.
The J wave is thought to have more malignant nature than the classical concave upwards ST segment elevation of early repolarization syndrome.
The J wave itself has been described as two types - one as a slurring of the terminal QRS in the region of J point with smooth transition to the ST segment and another with a notch of positive spike at the end of the QRS.
It may be noted that anterior upsloping ST segment elevation can be present without the early repolarization, which is now recognized to be a normal pattern in young males.
Recognition of this fact has even resulted in revision of criteria for diagnosis of ST elevation myocardial infarction where more ST segment elevation is required in anterior leads than other leads.
Antzelevitch C et al divided early repolarization syndrome into three types. Type 1 was early repolarization pattern predominantly in lateral leads, prevalent in healthy male athletes. Type 2 was predominantly in inferior and inferolateral leads and associated with a higher level of risk.
Type 3 displayed early repolarization pattern globally in inferior, lateral, and right precordial leads and was associated with highest level of risk for development of malignant arrhythmias and ventricular fibrillation storms.
ECG showing early repolarization syndrome. Concave upwards ST segment elevation with a notch at the end of the QRS complex or a slurring of the terminal QRS seen in lateral leads is characteristic of early repolarization syndrome. This one apparently belongs to the type 1 described above.
Sacher F et al mentioned that having an ERPS pattern is not a disease by itself. But it is crucial to give importance when there is a family history of sudden cardiac death and in patients with syncope having dramatic J point elevation and a descending/horizontal ST segment.
They mentioned that even though 5% of Caucasian population may have this ECG pattern, only 1/2500 are at risk of ventricular fibrillation.
Another ECG showing early repolarization syndrome, as evidenced by the concave upwards ST segment elevation in leads V2 to V6. A closely similar pattern can occur in hyperacute phase of myocardial infarction.
Moreover, persons with ERPS can also develop myocardial infarction. So, if the clinical history is suggestive of ischemic cardiac pain, it is better to have follow up with serial ECGs and troponin estimations.
The ECG pattern of ERPS can be abolished by exercise or atropine which increases the heart rate. Potassium administration may also abolish the change. But these methods are not to be adopted in a person with suspected acute coronary syndrome.
There are studies which find no association between ERPS and cardiac mortality. In a study of 29,281 ambulatory patients, they found components of ERPS associated with decreased cardiovascular mortality, which was not significant after adjustment for age. This was because the patterns were more common in young individuals.
A meta-analysis included 29 studies with 182,135 subjects in the general population and 14 studies with 8087 subjects in physically active individuals. Worldwide prevalence of early repolarization pattern in general population was 11.6%.
They found higher incidence of 17% in males vs 6.2% in females. Prevalence of early repolarization pattern in physically active individuals was 33.9%.