FIGURE 3.

Scatter plots of vagal activity values. Peri-operative values (top panels), post-operative values (middle panels), and long-term recovery values (bottom panels) are reported on the vertical axis, as a function of pre-operative values, which are in all panels reported on horizontal axis (each dot represents one patient). They are computed, respectively, as values on T3, average between T4 and T5, average between T9 and T10, average between T1 and T2. Changes in day-time values (measured from noon to 8 pm) are shown on the left and changes in the night-time values (measured from 10 pm to 6 am) are shown on the right. Linear regression is shown as a full black line and the line of identity is shown as a dashed black line. Correlation coefficient r is reported for each plot separately. Significances are all p < 0.08. While the event of surgery clearly reduces the vagal activity, the rehabilitation process gradually restores it to the original values. In fact, in some cases final vagal activity values are actually higher than the original pre-operative values. This effect is especially pronounced during the night (due to logarithmic representation of vagal activity values, real changes are actually more pronounced than it appears). See text and Table 2. Figures have different numbers of points, since for 16 patients that completed the study certain daily and/or nightly values are missing.