Early repolarization syndrome (ERS) is a cardiac abnormality, once thought to be benign, that is characterized by J-point elevation. It is associated with fatal arrhythmic conditions and sudden cardiac death.
Early repolarization syndrome (ERS) is a condition represented by the electrocardiographic finding of an elevated J-point, indicated by the presence of a notch on the QRS complex, or an unclear transition of the QRS to the ST segment . ERS has been reported to have a higher prevalence in individuals of African or Southeast Asian descent . In addition, males are more frequently affected than females . ERS is also more common in the context of hypertrophic cardiac defects, overactive vagal tone, electrolyte abnormalities (particularly hypercalcemia), cocaine use, athletes, hypothermia, and certain ECG abnormalities .
In the past, ERS was considered a benign variation of normal physiology. Subsequent studies showed that it is linked to an increased incidence of various cardiac events, most prominently, idiopathic ventricular fibrillation (VF), even in the absence of cardiac comorbidities. Another major concern in ERS is the increased prevalence of sudden cardiac death (SCD). It is thought that a genetic component, in the form of inheritable mutations, may be involved in the etiology of ERS . An autosomal dominant pattern of inheritance is suggested, with varying degrees of penetrance .
ERS can present in two ways, the first being symptomatic ERS. Patients often have arrhythmias and ischemia, where the latter can lead to ventricular fibrillation . Those who have a history of myocardial infarction or syncope are also included in this subgroup . Symptomatic ERS carries a higher risk of cardiac events in the future . The alternative presentation of ERS is an asymptomatic disease that is often found incidentally. The clinical course for such individuals may be benign or consist of further cardiac disease.
ERS is diagnosed via electrocardiography. The main finding is an elevation between the QRS and ST segments of over 1 millimeter above the baseline, as well as ST elevation with prominent T waves in at least two leads . This may appear as slurring of the QRS complex or a notch just before the end of the segment. Both these abnormalities should be positive deflections. It has recently been agreed that ST elevation is not necessary for the diagnosis of ERS, however, in some cases ST elevation is the most obvious abnormality.
In asymptomatic patients, the electrocardiographic tracing is described as an ER pattern. ERS is diagnosed in those who have experienced symptoms due to serious arrhythmias such as ventricular fibrillation or ventricular tachycardia . Patients diagnosed with ER pattern have a tripled risk of VF compared to the general population.
ERS is part of a spectrum of "J wave syndromes" which also include Brugada syndrome . Events such as ST-segment elevation myocardial infarction (STEMI) and hypothermia are also known to produce a similar ECG pattern . The above-mentioned disorders should be excluded as possible causes.
The degree of J-point elevation may correlate to the prognosis . In addition, a descending ST segment is a poor prognostic indicator .