Early repolarisation syndrome

Early repolarization syndrome (ERS) presents in structurally normal hearts as life-threatening ventricular arrhythmia. Affected individuals typically come to clinical attention in young to middle adulthood, often through resuscitated cardiac arrest, syncope, or polymorphic ventricular tachycardia/ventricular fibrillation occurring in the absence of structural heart disease, myocardial ischaemia, or another identifiable cause. The defining electrocardiographic feature is the early-repolarisation pattern (ERP; J-point elevation with notching or slurring) in two or more contiguous inferior or lateral leads. Presentation ranges from an asymptomatic ECG pattern at one end of the spectrum to recurrent ventricular fibrillation at the other; the historical view of early repolarisation as universally benign is no longer accepted when inferolateral J-waves coexist with documented ventricular arrhythmias. Recognised high-risk features include inferolateral pattern location, J-point amplitude greater than 0.2 mV, and a horizontal or downsloping ST-segment, associated with elevated risk of sudden cardiac death.

The estimated prevalence of the usually benign early-repolarisation pattern in the general population ranges from approximately 1% to 33%. This figure varies with the J-point threshold and lead criteria applied; the symptomatic syndrome itself is rare.

The mode of inheritance of ERS has not been fully established. Familial clustering has been reported, suggesting a heritable component in some cases, but the genetic architecture appears heterogeneous. When a disease-causing variant is identified in a family, recurrence risks and predictive testing recommendations should be based on the inheritance pattern associated with the specific genetic condition.

Early repolarisation syndrome (ERS) refers to a specific anomaly on the electrocardiogram (ECG), known as the early repolarisation pattern (ERP). This pattern is characterised by a positive deflection (J wave) that appears immediately after the QRS complex, particularly in inferolateral ECG leads. While the early repolarisation pattern is relatively common (1–13%) and is usually considered benign in healthy, asymptomatic young people and athletes, there is growing evidence suggesting a potential link to severe cardiac arrhythmias and sudden cardiac death.

The link between ERP and malignant arrhythmias is further supported by J‑wave amplification before the onset of ventricular fibrillation (VF), VF storms, and premature ventricular contractions (PVCs). Clinical studies have shown that among patients who survived idiopathic ventricular fibrillation, about 31% exhibited an ERP, compared to only 5% in a control group without heart disease.

• Genetic testing may be considered in patients with clinically diagnosed early repolarization syndrome following unexplained cardiac arrest; however, it is not recommended in asymptomatic individuals with an isolated early repolarization ECG pattern.
• Establishing the diagnosis confirms the clinical suspicion at the molecular level and provides the basis for genotype-informed management.
• Enabling specific and individualised surveillance and thereby supporting personalised medical care, planned and implemented by the treating physicians in consultation with the affected individual.
• Allowing predictive testing of at-risk family members once the familial pathogenic variant has been identified.

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