ABSTRACT
BACKGROUND: Non-invasive positive pressure ventilation (NIPPV) is known to enhance hypoventilation and is particularly adopted as a treatment for patients diagnosed with obesity hypoventilation syndrome (OHS). The augmented risk of cardiovascular morbidity is known as a side effect of OHS. AIMS: In this paper, this inference is examined that hypoventilation and the increased risk of morbidity can be diagnosed via the assessment of changes in heart rate variability (HRV). More specifically, the study investigates the effect of NIPPV on both HRV and hypoventilation among OHS patients. The linear relationship between different HRV measures and ventilation parameters is also examined. MATERIALS & METHODS: The reported results are attained via an interventional clinical trial study. HRV measures are evaluated before and after treatment, in a group of patients which are newly diagnosed with OHS and receive bi-level positive airway pressure (BiPAP) treatment for three months. RESULTS: The results are compared and interpreted via statistical analysis. DISCUSSION: Throughout the study, the relationship between hypoventilation and HRV is confirmed, as well as the effect of BiPAP on some HRV measures in both time and frequency domains. Particularly significant connections are observed between hypoventilation and low-frequency components of HRV. CONCLUSION: The enhanced respiration due to the application of BiPAP can improve the performance of autonomous nervous and cardiovascular systems, in terms of HRV. Moreover, it is suggested to consider some HRV parameters to control the cardiovascular side-effects of OHS and confine the resulting mortality rate in long term.