A preliminary study on the effect of breathing on heart rate and blood pressure variability in patients with chronic diseases with abnormal sleep breathing
Authors: Zhou Qingqing , Sun Xingguo , zhang yanfang 
Published: May 2022

ObjectiveTo analyze the relationship between heart rate and blood pressure variability and respiration in patients with chronic respiratory disorders during night sleep.Methods16 patients with chronic diseases with abnormal sleep and respiration were included. Polysomnography was used to analyze the R‐R interval of nasal airflow electrocardiogram in normal stable breathing period and wave breathing period (OB) during nighttime sleep, and the variation of blood pressure based on finger‐tip photoelectric volume pulse wave (PPG) and pulse wave conduction time (PTT).The ResultsThe ratio of the number of respiratory cycles to the number of heart rate variability cycles (B‐n / HRV‐n) was (1.00 ± 0.04), to the number of systolic blood pressure (SBP) variability cycles (B‐n / SBPV‐n) was (1.02 ± 0.10), and diastolic blood pressure (DBP) variability cycles (B‐n / DBPV‐B‐n) was (1.00 ± 0.11), The ratio of respiratory cycle number to heart rate variability cycle number (OB‐n / OB‐HRV‐n) during OB was (1.22 ± 0.18). The ratio of respiratory cycle number to systolic blood pressure variation cycle number (OB‐n / OB‐SBPV‐n) was (1.19 ± 0.22), and DBP(OB‐n / OB‐DBPV‐n) was (1.15 ± 0.15), both of which were higher than those in normal stable breathing period (P < 0.01). During the normal and stable breathing period, the average amplitude of heart rate variability (HRV‐B‐M) of each respiratory cycle rhythm was (2.64 ± 1.59) bpm, the average amplitude of systolic blood pressure variability (SBPV‐B‐M) of each respiratory cycle rhythm was (2.83 ± 1.22) mmhg, and diastolic blood pressure variability (DBPV‐B‐M) was (2.40 ± 0.86) mmhg, which were slightly higher than those of the normal people, but there was no significant difference compared with the normal people and hypertensive patients without sleep apnea. The mean amplitude of heart rate variability (OB‐HRV‐B‐M) at each respiratory cycle rhythm in OB period was (3.56 ± 1.57) bpm, the mean amplitude of heart rate variability (OB‐HRV‐OB‐M) at each OB period was (13.75 ± 4.25) bpm, The average amplitude of diastolic blood pressure variability (OB‐DBPV‐B‐M) was (2.82 ± 1.95) mmhg, which was higher than that in normal stable respiratory period. The difference between OB‐SBPV‐B‐M and normal stable respiratory systolic blood pressure variability (SBPV‐B‐M) was significant. The variation range of systolic blood pressure (OB‐SBPV‐OB‐M) in each OB cycle was (16.83 ± 9.29) mmhg, which was much larger than that of OB‐SBPV‐B‐M and SBPV‐B‐M (P < 0.01).ConclusionThe variations of blood pressure and heart rate in patients with chronic respiratory disorders during normal and stable breathing at night are similar to those in normal people and hypertensive patients without sleep respiratory disorders in the same period in our laboratory, The variation amplitude of heart rate and blood pressure in wavy breathing period was greater than that in normal and stable breathing period .confirming that the variation of heart rate and blood pressure was respiratory origin.