Fig. 5

Scatter plot of cutoff value of respiratory variation of aortic peak velocity in included studies. The cutoff values of included studies are as follows: (1) Durand 2008 [30], 12%; (2) Choi 2010 [31], 20%; (3) Renner 2011 [32], 7%; (4) Pereira 2011 [33], 10%; (5) Byon 2013 [34], 11%; (6) Lee 2014 [35], 14%; (7) Lee 2015 [36], 13.5%; (8) Krishna 2016 [37], 12.2%; (9) Favia 2017 [38], 16.5%; (10) Lee 2017 [39], 12%; (11) Morparia 2018 [40], 12.3%