Holter analysis confirmed individual ECG abnormalities such as supraventricular extra-systoles, intermittent bundle branch blocks, alterations in the periods between QRS complexes, and atrial fibrillation in MYO5b-KO compared with WT mice (Figure 4D and E; see Supplementary data online, Figures S3I and S4C). Here, MYO5B is linked to atrial fibrillation.