On the relationship between heart weights, fibrosis, and QRS duration

This study analyzed the effects of heart weights, myocardial fibrosis, sex, and body length upon the duration of the QRS complex. A positive correlation was found between presence or absence of fibrosis and duration of the QRS complex. A positive correlation was also found between weights of the heart and QRS duration, but this correlation appeared to be spurious and due to the tendency of fibrosed hearts to be heavier than those with normal myocardium.