Variability of Heart Rate as a Marker of Complication of Colorectal Surgery

Heart rate variability reflects the autonomic nervous system on the intrinsic activity of sinus node cells. Sympathetic hyperactivity is an adaptation to stress, while parasympathetic hyperactivity is present at rest. Thus, any variability in the heart frequency rate reflects variations in sympathetic and parasympathetic components in the autonomic nervous system. Failure to return to normal or a reduction in the variability of the heart rate in the postoperative period is correlated with complications in colorectal surgery.