<qa>  What is the ratio of lower frequency and higher frequency heart rate rhythmic oscillations expressed asThe ratio of lower frequency LF and higher frequency HF heart rate rhythmic oscillations is expressed as an index of sympathovagal balance. Patients with chronic renal disease participate in the study. Blood pressure and power spectrum of heart rate variability for 24 hours are measured when they receive no medication for at least 1 week. The mean waking and sleeping time systolic and diastolic blood pressure are calculated. LFHF ratios in the chronic renal disease are evaluated to calculate the wakingsleeping ratio for LFHF. 