Figure 2
From: Coronary artery bypass surgery and longitudinal evaluation of the autonomic cardiovascular function
Longitudinal evaluation of heart rate variability in patients undergoing coronary artery bypass grafting surgery. Longitudinal results of spectral analysis of heart rate variability in the three groups: CABG, patients who underwent coronary artery bypass grafting; CAD, patients with coronary artery disease who did not undergo surgery; healthy, control subjects without CAD. Total power (a) and low-frequency power (b) indicate both adrenergic and parasympathetic modulation of heart rate; high-frequency power (c) represents the parasympathetic component; and the low-frequency/high-frequency ratio (d) represents autonomic balance that modulates heart rate. *P < 0.05 versus CABG preoperative value; †P < 0.05 versus CABG day 3 or 6; ‡P < 0.05 versus CABG and CAD, except high frequency, for which ‡P < 0.05 versus CAD.