Autonomic modulations in patients with bronchial asthma based on short-term heart rate variability

Abstract

Background:Although enhanced cholinergic activity of asthmatics has been established early on, little heart rate variability (HRV) studies were done on asthma patients. Previous HRV studies were based on 24-hour recordings and therefore have not considered the extremely labile activity of bronchial asthma.Objective:To evaluate the pattern of autonomic modulations in asthmatic patients based on short-term HRV studies.Materials and Methods:The study involved 100 asthmatic patients with an age range of 20-40 years. Asthma activity was evaluated over the last month prior to patients’ assessment using asthma control test (ACT). Allflow Spirometer was used for assessing pulmonary function, while Biocom 3000 electrocardiography recorder was used for studying 5-minute HRV. Data was analyzed using the Statistical Package for the Social Sciences Software. Heart rate and asthma medications were introduced as a covariate when studied variables were screened for significant correlation between measurements of asthma severity and heart rate variability indices using partial correlations.Results:The level of asthma control correlate positively with both normalized low frequency (LF Norm) and the ratio of low frequency/high frequency (LF/HF) (CC = 0.302, 0.212 and P = 0.002, 0.036, respectively) and negatively with HF Norm (CC = -0.317, P = 0.001). Duration of asthma correlates positively with normalized high frequency (HF Norm) (CC = 0.235, P = 0.020) and negatively with LF Norm (CC = -0.250, P = 0.013).Conclusion:Poor asthma control is associated with lower HRV, depressed sympathetic and enhanced parasympathetic modulations especially in those with longer asthma duration.

Heart Rate Variability and Autonomic Modulations in Preeclampsia

“…This fact explains the extremely significant association between MHR and HRV parameters subjected to regression analysis in our study. It also explains why MHR was introduced as a covariate while comparing HRV of different groups in the present study and others [ 15 , 17 ].…”

Perspectives of patients and healthcare professionals on mHealth for asthma self-management

“…Other physiological parameters that were identified as being useful included measurements of heart rate, respiratory rate and sleep quality. Given that heart rate variability may be associated with asthma control [24], that respiratory rate variability during sleep may differ between individuals with and without asthma [25], and that nocturnal wakening is a common complaint of individuals with asthma, the potential for these measurements to provide support for asthma self-management warrants further investigation. Each year 5.5 million deaths can be attributed to poor air quality [26], whilst air pollution exposure is associated with increased frequency of asthma attacks in children and adults [27].…”

Patterns of heart rate variability and cardiac autonomic modulations in controlled and uncontrolled asthmatic patients

“…Bronchial asthma has received special attention by researchers investigating the impact of autonomic disturbances on the disease etiology [ 5 – 11 ]. Low HRV and predominance of parasympathetic modulations on the heart were demonstrated in some studies [ 5 – 8 ], but not others [ 9 – 11 ]. According to some previous reports, parasympathetic discharge seems to predominate in asthmatic patients irrespective of day-and-night cycle [ 12 ] or physical activity [ 5 ].…”

“…Enhanced parasympathetic drive is expected to increase HRV. Nonetheless, most studies in asthmatic patients that document shift of sympathovagal balance towards predominance of parasympathetic drive also demonstrate reduced HRV [ 5 – 8 ]. These contradictory findings are difficult to explain physiologically and may point to hidden confounders [ 15 – 18 ].…”