Dear Drs Joyce & Ferns,

We thank you for your correspondence regarding our recent study entitled “The neonatal QRS complex and its association with left ventricular mass”.

We greatly appreciate your thoughtful analysis of our findings and the comparisons with your own research. We find your data regarding the correlation of left ventricular (LV) ECG criteria highly relevant and interesting. It is fascinating to note that LV ECG criteria correlated better with LV mass fraction than LV mass indexed to body surface area. We believe these findings strongly resonate with our own observations and can significantly contribute to our understanding of cardiac physiology in neonates.

We fully agree with you and share your enthusiasm for investigating these findings further within our large cohort. We are currently in the process of reanalyzing the entire echocardiographic data set as the required parameters for calculation of right ventricular (RV) size and mass were not registered at the initial evaluation. Therefore, we unfortunately do not have RV data available to share with you at this point.

Once again, thank you for your valuable insight and suggestions.

Sincerely,

Julie Molin and Alex H. Christensen.