2000 Progress Report: Relationship of Ambient Particulate Matter to Heart Rate Variability and Cardiac Arrhythmias in Elderly Adults with Coronary Artery Disease

EPA Grant Number: R826783
Title: Relationship of Ambient Particulate Matter to Heart Rate Variability and Cardiac Arrhythmias in Elderly Adults with Coronary Artery Disease
Investigators: Ostro, Bart , Lipsett, Michael
Current Investigators: Ostro, Bart , Tager, Ira , Woo, Mary , Lipsett, Michael , Bolton, Merle
Institution: California Office of Environmental Health Hazard Assessment
Current Institution: Public Health Institute , California Office of Environmental Health Hazard Assessment , Eisenhower Medical Center , University of California - Berkeley , University of California - Los Angeles , University of California - San Francisco
EPA Project Officer: Chung, Serena
Project Period: October 1, 1998 through September 30, 2000
Project Period Covered by this Report: October 1, 1999 through September 30, 2000
Project Amount: $436,964
RFA: Health Effects of Particulate Matter and Associated Air Pollutants (1998) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Human Health , Particulate Matter , Air

Objective:

In previously published studies, we found an association between PM10 and daily mortality in Coachella Valley, an area dominated by coarse geologic particles. The mechanisms that underlie the associations, however, are unknown. In this project we will examine associations between PM and two intermediate outcomes that relate to the electrical activity of the heart in potentially susceptible individuals: the balance of sympathetic and parasympathetic nervous system tone, measured as heart rate variability (HRV); and the incidence of specific cardiac rhythm disturbances or arrhythmias. Our study sample is an elderly cohort of people living in Coachella Valley, aged 65?80, with established coronary artery disease (CAD), who were willing to undertake weekly 24-hour Holter monitoring for at least 10 weeks.

Progress Summary:

We conducted a pilot study of 11 subjects with established heart disease in 1999. Through this initial effort, we found that people would be willing to undertake 24-hour Holter monitoring once a week over a 10-week period. We also found significant problems relating to the use of standard Holter monitoring devices, as well as with the HRV editing and scanning technology employed in the pilot phase. As a result, we revised our protocol and undertook tests of other equipment. Ultimately, we decided on digital Holter monitors (model Trillium 3000TM) and PC-based software from Forest Medical (Syracuse, NY). In the spring of 2000, we recruited 23 subjects from a large cardiology practice in Coachella Valley. The subjects, aged 65-80, had established CAD, and were willing to participate in 24-hour Holter monitoring once a week for up to 12 weeks. A subset of subjects also were willing to have indoor PM monitoring of their homes while they were wearing the Holter monitors. Ultimately, 20 subjects completed 8 weeks or more of approximately 24-hour Holter monitoring. Three subjects were discovered, through their participation in this study, to have experienced asymptomatic, but life-threatening, arrhythmias requiring placement of implantable defibrillators. The monitoring was conducted from February to early May 2000. Besides an intake questionnaire, we collected, on the day of Holter monitoring, hourly data on symptoms, time spent outdoors, use of air conditioning, and whether windows were open or not. The Holter scan files were downloaded to a PC and edited by an experienced EKG technician. We also collected daily data on meteorological variables and ambient pollutant levels at fixed site monitoring stations, specifically PM10, PM2.5, ultrafine particles, ozone, carbon monoxide, and nitrogen dioxide. For a subset of the participants, we also collected indoor PM2.5 and PM10 data using passive DataRam monitors. Ultimately, the entire data set was cleaned, checked, and merged into a statistical database.

At the outset of the analysis, we developed descriptive statistics to characterize the participants and the environmental exposures. In the fall of 2000, we began our primary analysis using SAS Proc Mixed procedures, examining associations between various measures of HRV and ambient and indoor pollution. As we began this process, we found?through the quality assurance/quality control (QA/QC) of the HRV Holter editing?that there were problems with the original editing of a number of the files. This led us, after careful re-examination of many of the edits, to decide to re-edit all the Holter files with the assistance of a highly recommended EKG technician from the University of California at San Francisco School of Medicine. This unanticipated re-editing process took several months, as the EKG technician was only available on a part-time basis. At the completion of her work, we discovered a bug in the HRV software; the manufacturer had its programmers develop and provide a patch, which cannot be applied globally, but had to be applied to each edited file. With these various delays, we are nearly ready to begin the final analyses.

During this period, we also worked with researchers from the University of Southern California to undertake monitoring of PM10, coarse and fine particles, and their constituents?both inside and outside the homes of a subset of our participants.

Future Activities:

We now anticipate that the data will be re-edited by September 15, 2001, and we will begin the analysis soon after that. We will first determine the empirical associations between the indoor and outdoor PM, using the monitor and daily diary data that were collected for a subsample of the participants. Then, we will apply these empirical estimates to the full data set. We can then test for the association between both time and frequency domain measures of HRV and crude outdoor and adjusted outdoor PM (including PM2.5, PM10, and coarse particles). We anticipate a draft report by January 1, 2002, and a final report by March 15, 2002.


Journal Articles on this Report : 1 Displayed | Download in RIS Format

Other project views: All 6 publications 2 publications in selected types All 2 journal articles
Type Citation Project Document Sources
Journal Article Geller MD, Chang M, Sioutas C, Ostro BD, Lipsett MJ. Indoor/outdoor relationship and chemical composition of fine and coarse particles in the southern California deserts. Atmospheric Environment 2002;36(6):1099-1110. R826783 (2000)
R826783 (2003)
R826783 (Final)
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  • Supplemental Keywords:

    PM10, particulate matter, fine particles, coarse particles, epidemiology, heart rate variability, cardiovascular, arrhythmia, heart disease, elderly, California, CA, health effects, human health, heart rate., RFA, Health, Scientific Discipline, Air, particulate matter, Health Risk Assessment, Risk Assessments, Susceptibility/Sensitive Population/Genetic Susceptibility, Disease & Cumulative Effects, Biochemistry, genetic susceptability, indoor air, ambient air quality, sensitive populations, health effects, particulates, cardiac arrhythmia, human health effects, morbidity, PM 2.5, inhaled pollutants, cardiovascular vulnerability, exposure, heart rate variability, air pollution, human exposure, chronic health effects, susceptibility, Acute health effects, coronary artery disease, elderly, ambient particulates, environmental stressors, environmental toxicant, sensitive subgroups, human susceptibility, indoor air quality, mortality, inhaled particles, cardiac arrhythmias, ultrafine particles, exposure assessment, heart rate , environmental hazard exposures

    Progress and Final Reports:

    Original Abstract
  • 1999
  • Final Report