Letter by Hayashi et al regarding article, "Heritability of early repolarization: a population-based study".

Letter by Hayashi et al Regarding Article, “Heritability of Early Repolarization: A Population-Based Study” To the Editor: We read with much interest the article published by Reinhard et al.1 The article described a high rate of heritability of early repolarization (ER) in a general population. Early repolarization was characterized by ECG morphological features of the QRS complex (ie, notching, slurring, or both). The heritability of ER was present according to regions and phenotypic criteria of ER. The authors also reported higher familial transmission of ER in motherthan in father-affected cases. They showed ECG examples of ER in the inferior leads of different morphological features in the Figure. The morphological criteria of ER are obscure. In the ECG examples, the mother apparently shows the notching type of ER in both II and aVF leads. In contrary, the son shows the slurring type of ER in the same leads. However, the son’s ECG exhibits a small notch in lead aVF that is absent in lead II. In addition, the daughter presents the notching type of ER in lead II, as mentioned in the annotation of the Figure. The QRS configuration of the daughter’s ECG in lead II is identical to that of the son’s ECG in lead aVF. What was the differential feature between the notching and slurring type of ER? Moreover, the daughter’s ECG in lead aVF looks like the slurring morphological features of ER, but it says that “the daughter presents with both notching (lead II) and slurring (lead aVL) type ER” in the annotation, although no ECG of lead aVL is shown in the Figure. Which ECG lead exactly exhibited the slurring type of ER in the daughter adopted as a representative?