VAPB and Bradycardia: Surface ECG recordings of VAPB−/− mice (Fig. 5H–N and Supplemental Figs. 10 and 11) revealed a sino-atrial bradycardia (Fig. 5H, I), as heart rates were reduced while the duration of the PQ interval, corresponding to atrio-ventricular conduction, was unchanged (Fig. 5J, K).