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Mohammed J.1,2, Derom E.3, Van Oosterwijck J.1,4, Salhi B.5, Da Silva H.1, Calders P.1
1Ghent University, Rehabilitation Sciences and Physiotherapy, Ghent, Belgium, 2Bayero University, Kano, Physiotherapy, Kano, Nigeria, 3Ghent University, Respiratory Medicine, Ghent, Belgium, 4Research Foundation - Flanders (FWO), Brussels, Belgium, 5Ghent University Hospital, Pulmonary Rehabilitation Division, Ghent, Belgium
Background: Patients with chronic obstructive pulmonary disease (COPD) show impairments in several parameters of the autonomic nervous system functioning including a significant lowering of the heart rate variability (HRV) values. This study was aimed at assessing the immediate effect of deep breathing, tilting and valsalva maneuver techniques on the HRV in subjects with COPD.
Purpose: To investigate the changes in HRV following deep breathing, head up tilt and valsalva maneuver techniques among subjects with COPD.
Methods: Twenty male COPD patients (38±16.8% FEV1 predicted) with a mean age of 65±9.8 years attending a pulmonary rehabilitation programme in Ghent University Hospital, Belgium, participated in this study. A continuous electrocardiography (ECG) monitoring and beat-to-beat blood pressure recording of the participants in supine position during rest, deep breathing (at a rate of 6 cycles/minute), head up tilt (0 to 60 degrees) and valsalva maneuver (recovery phase) was performed using a Finapres ECG machine. Clinical and demographic variables such as lung function, age, weight and height were also collected. Thereafter, the beat-to-beat (heat rate) data was retrieved and analyzed on the Kubios HRV (2.2) software in order to generate linear (time & frequency domains analyses) and non-linear parameters of HRV. The time domain analyses of HRV included standard deviation of NN intervals (SDNN) and the root mean square of successive differences (RMSSD) expressed in milliseconds (ms). Frequency domain analyses such as high frequency (HF) and low frequency (LF) bands expressed in both absolute (ms2) and normalized units (nu) were also retrieved. The non-linear HRV parameters were limited to standard deviations 1 and 2 (SD1/SD2), also expressed in milliseconds. Descriptive and inferential statistics were used to analyze the data obtained on SPSS 22. Alpha probability value was significant at 0.05.
Results: The results revealed that compared to resting HRV values, deep breathing caused a significant increase in the SDNN, LFnu and SD2, and a significant reduction in the HFnu values (p 0.05). The results further showed that compared to the HRV during rest, valsalva maneuver recovery phase was characterized by a significant reduction in the HRV parameters of SDNN, RMSSD, SD1 and SD2 (p 0.05). However, the frequency domain analyses of HRV remained unchanged following valsalva maneuver compared to rest (p>0.05). No significant changes were recorded in the HRV parameters of the subjects following head up tilt test (p>0.05).
Conclusion(s): It was concluded that subjects with COPD undergoing pulmonary rehabilitation exhibit residual autonomic function deficits (abnormal valsalva response).
Implications: This study has highlighted the potential of using the HRV as an important prognostic outcome for cardiovascular health for subjects undergoing COPD rehabilitation.
Funding acknowledgements: Jibril Mohammed is a third year PhD student at the Department of Rehabilitation Sciences and Physiotherapy of Ghent University, Belgium. He is also a staff (academic) of Bayero University, Kano, Nigeria. His doctoral research is entitled ''autonomic function in patients with Chronic Obstructive Pulmonary Disease (COPD)''. He qualified as a physiotherapist from Bayero University, Kano in Nigeria in 2006. He obtained his Master of Science in Physiotherapy from the Obafemi Awolowo University, Ile-Ife, Nigeria in 2010. He is registered with the Medical Rehabilitation Therapist Board of Nigeria (MRTBN) and currently holds a professional practicing license. His area of interest is cardiorespiratory rehabilitation. His research topics of interest are focused in the areas of COPD, pulmonary/cardiac rehabilitation, exercise therapy, and autonomic function. He has authored several national and international peer-reviewed publications in the scientific literature.
Topic: Cardiorespiratory
Ethics approval: Ethical approval was sought and obtained from the ethical committee of Ghent University Hospital, Ghent, Belgium (Reference number: BE670201628572)
All authors, affiliations and abstracts have been published as submitted.
