Fig. 4
Effect of vagotomy (VgTx) in the time-domain analysis of heart rate variability. a Relationship between the duration of the following cardiac cycle ((R–R)n+1) and the previous one ((R–R)n) in a control animal, before and after vagotomy. b Relationship between the duration of (R–R)n+1 and (R–R)n in a CNH rabbit, before and after vagotomy. c Mean SD1 (left) and SD2 (right) from control (n = 6) and CNH (n = 6) rabbits before and after vagotomy (VgTx). Mean SD1 and SD2 were statistically unaffected by vagotomy. Before vagotomy: filled circles. After vagotomy: empty circles. Empty bars: control rabbits. Dotted bars: control rabbits after vagotomy. Filled bars: CNH rabbits. Lined bars: CNH rabbits after vagotomy. Dispersion bars: SEM