Effects of Air Pollution on Heart Rate Recovery and Heart Rate Variability in Patients with Coronary Artery Disease
Date Issued
2011
Date
2011
Author(s)
Hsieh, An-Chi
Abstract
Previous studies had shown that air pollution exposure may cause short-term and long-term health effects, especially on respiratory and cardiovascular disease. Cardiovascular disease has been the leading cause of death in Taiwan. It is known that air pollution may influence the sympathovagal regulations, and increase the risk of cardiovascular disease morbidity and mortality. Heart rate recovery (HRR) and heart rate variability (HRV) have been used as a heath indicator of autonomic function. However, most air pollution studies have been focused on HRV. The effects of air pollution on HRR haven’t been investigated. Thus, in this study we studied the effects of air pollutants on HRR in patients with coronary artery disease (CAD).
This study recruited 57 CAD patients based on symptom-limited exercise treadmill test and electrocardiogram at Chia-Yi area in Taiwan between December 2005 and March 2007. Each patient was examined once every three months for totally 4 times. HRR was defined as the difference between the peak heart rate during the exercise and the recovery heart rate after the exercise. CO, NO2, SO2, O3, PM10 , PM2.5, temperature and humidity data recorded by 6 air monitoring stations from EPA were gathered and daily averages were calaulated. We used mixed effect model to determine the effects of air pollution on both HRR and HRV in CAD patients. Furthermore, we used two-pollutant models to estimate the effects using both single-lag model and moving-average model from day 1 to day 5.
The trend of both accumulative and single-lag effect of SO2 exposure was significantly associated with decreased HRR from first to sixth minute. Besides, the associations of SO2 were even substantially increased after O3 was controlled in both moving-average models and single-lag models. The associations between particulate matters (PM10 and PM2.5) and HRR were significant in warm season. According to the influence of different directions of wind on HRR, PM10 mainly come from northwest.
On the other hand, particulate effect had been shown in frequency domain HRV parameters and the associations of PM10 and PM2.5 were still significant after O3 was controlled in LF. Based on the effects of different directions of wind on HRV, PM2.5 come from southwest more than northwest.
Previous studies have shown that decreased HRR and HRV were significantly associated with cardiovascular morbidity and mortality. This study reveals an association between particles (PM10 and PM2.5) and decreased HRR as well as HRV in patients with coronary artery disease. Nevertheless, the representation on the sympathovegal activity of the two health indicators are different. It is better to use the frequency domain HRV parameters to evaluate the effects of air pollution than to use time domain HRV parameters. Patients with comorbidity and medication use may modify the effects of autonomic dysfunction by air pollution exposure. The adverse health effects of air pollution may be modified by patients with diabetes, hypertension or hyperlipidemia comorbidity, and β-blocker, calcium channel blocker, statin, angiotensin converting enzyme inhibitor or angiotensin receptor blocker medication use. Because the balance of autonomic nervous system may be toward parasympathetic nerve suppression, heart rate recovery could be used as a good index for investigating the interference of air pollutant on autonomic nervous system function, while its mechanism requires further study and analysis.
Subjects
air pollution
heart rate recovery
coronary artery disease
heart rate variability
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-100-R98844011-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):4e0248cf9ace4961d718b9a26cf75dd2