Valsalva

On the question of parasympathetic contribution in Valsalva

The mechanism of the tachycardia during the manoeuvre remains controversial, some workers suggesting exclusive enhancement of sympathetic activity and others suggesting depression of parasympathetic outflow; also, both parasympathetic withdrawal and increased sympathetic outflow  have been suggested (Bennett et al., 1976; Eckberg, 1980). The quantification of heart interval variations P65 Junqueira 2002 impaired autonomic control of heart valsalva