Fig. 1

Typical responses of systolic blood pressure (SBP) (a) and R-R interval (b) during the Valsalva maneuver (VM). (c) shows a typical linear regression result between SBP and R-R interval during Phase II and IV of VM. Cardiovagal baroreflex sensitivity Phase II and Phase IV were estimated from outlined with a dashed and a solid line, respectively. SBP, systolic blood pressure; VM, Valsalva maneuver