Abstract: Objective: Based on the hypothesis that respiration causes variability of circulatory indicators proposed by the holistic integrated physiology and medicine theory, the correlation between respiration and heart rate variability during sleep in chronically ill patients with abnormal sleep breathing is analyzed. Methods: Eleven chronically ill patients with abnormal sleep breathing and apnea-hypopnea index (AHI) ≥15 times/hr are recruited. After signing the informed consent, they completed the standardized symptomatic restrictive extreme exercise cardiopulmonary exercise testing (CPET) and sleep breathing monitoring Calculate and analyze the rules of respiratory nasal airflow and ECG RR interval heart rate variability during the oscillatory breathing (OB) phase and the normal steady breathing phase of the patient during sleep, and use the independent sample t test to compare with normal people and no sleep breathing abnormalities in the same period in this laboratory. Of patients with chronic diseases are more similar and different. Results: The peak oxygen uptake and anaerobic threshold (AT) of CPET in chronic patients with abnormal sleep apnea were (70.8±13.6)% Pred and (71.2±6.1)% Pred; 5 cases of CPET had exercise induced oscillatory breathing (EIOB), 6 An example is unstable breathing, which indicates that the overall functional status is lower than normal. In this group of patients with chronic diseases, AHI (28.8±10.0) beats/h, the ratio of the total time of abnormal sleep breathing to the total time of sleep (0.38±0.25); the length of the OB cycle (51.1±14.4)s. The ratio (Bn/HRV-B-n) of the number of breathing cycles in the normal and steady breathing period to the number of heart rate variability cycles in this group of patients with chronic diseases is 1.00±0.04, and the CV (SD of HRV-B-M/x) is (0.33 ±0.11), blood oxygen saturation (SpO₂) did not decrease significantly, the average amplitude of heart rate variability (HRV-B-M) of each respiratory cycle rhythm was (2.64±1.59) bpm, although it was lower than normal people (P<0.05) , But it was similar to chronic patients without sleep apnea (P>0.05). In this group of patients with chronic diseases, the ratio of the number of respiratory cycles to the number of heart rate variability cycles (OB-Bn/OB-HRV-B-n) during OB is (1.22±0.18), and the average amplitude of heart rate variability for each respiratory cycle rhythm in OB (OB -HRV-B-M) is (3.56±1.57)bpm and its variability (OB-CV = SD of OB-HRV-B-M/x) is (0.59±0.28), the average amplitude of heart rate variability in each OB cycle rhythm (OB-HRV-OB-M) is (13.75±4.25)bpm, SpO₂ decreases significantly during hypoventilation during OB, and the average decrease in SpO₂ during OB (OB-SpO₂-OB-M) is (4.79±1.39)%. The OB-Bn/OB-HRV-B-n ratio, OB-HRV-OB-M and OB-SpO₂-OB-M in the OB period are all significantly higher than the corresponding indicators in the normal stable breathing period Large (P<0.01). Although OB-HRV-B-M has no statistically significant difference compared with HRV-B-M in normal stable breathing period (P>0.05), its variability OB-CV is significantly increased (P<0.01). Conclusion: The heart rate variability of chronic patients with abnormal sleep breathing in the OB phase is greater than that of the normal stable breathing period. When the breathing pattern changes, the heart rate variability also changes significantly. The number of breathing cycles in the stable breathing period is equal to the number of heart rate variability cycles.The ratio is the same as that of normal people and chronically ill patients without sleep apnea, confirming that heart rate variability is respiratory origin; and the reduction of heart rate variability relative to the respiratory cycle during OB is directly caused by hypopnea or apnea at this time, and heart rate variability is also breathing source.

Key words: holistically integrated physiology and medicine, oscillatory breathing, heart rate variability