Before revision:  We provide a systematic delineation of vagal contributions to HRV across signal-analytical domains which should be relevant for the emerging field of bioelectronic medicine and the deciphering of the vagus code  .
After revision:  We provide a systematic delineation of vagal contributions to HRV across signal-analytical domains which should be relevant for the emerging field of bioelectronic medicine and the deciphering of the vagus code . Our findings also have clinical significance for in utero monitoring of fetal health during surgery .