J wave patterns--morphology, prevalence and nomenclature

The recent resurgence of interest in early repolarization has demonstrated a variation in the definition of the term and a consequent variation in the prevalence of the pattern in different studies. This can vary from 35% in males and 21.5% in females if ST elevation is not considered part of the definition, to 3.3% and 0.5% in females with the inclusion of ST elevation. In contrast, the prevalence of the Brugada Syndrome is in the order of 0.1%-0.2% in Japan for example and has been found to be significantly lower in Denmark. Standardisation of measurement definitions, particularly for early repolarisation, is required.