Introduction

Early repolarisation is a commonly seen ECG pattern, reported in 13% of population (1). According to the Heart Rhythm Society and European Heart Rhythm Association 2013 consensus paper (2), early repolarisation pattern (ERP) can be diagnosed if at least 1mm J point elevation can be seen in at least two contiguous inferior and/or lateral leads. J waves were first noticed during hypothermia and are commonly known as Osborn waves. They were then noted in young, fit people and were considered a juvenile pattern.

It was regarded a benign finding until a study by Haissaguerre (3) reported increased prevalence of ERP in patients with a history of idiopathic VF compared to the healthy population. This study started a debate on whether the commonly seen pattern meant increased risk of sudden cardiac death.

The presence of the J wave has been shown to increase the probability of VF from 3.4 in 100,000 to 11 in 100,000 (4). The fact that a commonly seen ECG variant may, however infrequently, correlate with potentially fatal consequences poses a significant dilemma.

The question has proven difficult to answer with some studies confirming Haissaguerre’s finding but others failing to link ERP to increased arrhythmic risk (5-9).