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Air Pollution and Implantable Cardioverter Defibrillators

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ClinicalTrials.gov Identifier: NCT00015574
Recruitment Status : Completed
First Posted : April 23, 2001
Last Update Posted : September 4, 2006
Tufts Medical Center
Information provided by:
National Institute of Environmental Health Sciences (NIEHS)

Brief Summary:
Community based studies have shown increased cardiovascular mortality associated with acute exposures to particulate air pollution. Electrocardiographic changes have also been reported in animals exposed to particles in controlled conditions. We have hypothesized that cardiovascular patients may experience life-threatening arrhythmias associated with particulate air pollution episodes. Implanted cardioverter defibrillator (ICD) devices continuously monitor the heart rhythm, and on detecting arrhythmias can initiate interventions. These devices provide a passive, continuous monitor of cardiac arrhythmias. We are assessing the association between community exposures to air pollution measured by ambient monitors and these cardiac arrhythmias detected by implanted cardioverter defibrillator devices.

Condition or disease

Detailed Description:

Records of cardiac arrhythmias detected in patients with implanted cardioverter defibrillators will be linked with measurements of the concentration and constituents of ambient particulate air pollution. Time series methods will be used to assess temporal associations, adjusting for seasonal, weekly, and diurnal patterns, meteorology, and co-pollutants. Characteristics of subjects showing the strongest air pollution associations will be assessed, as well as effect modification by medication and co-morbidities.

ICD patients are followed up clinically every three to six months. The ICD device is interrogated and data are retrieved by non-invasive radio frequency retrieval from the implanted device. Device performance is checked. Detected arrhythmias and therapeutic interventions are listed. For each detected episode, date and time is recorded, along with a short electrogram of the heartbeats immediately before and during the event.

Daily ambient particle mass (PM10 and PM2.5) and particle constituents have been measured in Boston since January 1995. The Massachusetts Department of Environmental Protection has measured concentrations of gaseous pollutants including carbon monoxide, nitrogen dioxide, ozone, and sulfur dioxide. Meteorological factors including temperature, humidity, and barometric pressure have been measured at the National Weather Service station at Logan airport. Meteorologic factors and gaseous co-pollutants will be considered as independent predictors of arrhythmic events, and as confounders of the particulate air pollution associations.

Study Type : Observational
Estimated Enrollment : 500 participants
Observational Model: Defined Population
Observational Model: Natural History
Time Perspective: Longitudinal
Time Perspective: Retrospective/Prospective
Study Start Date : September 1998
Estimated Study Completion Date : September 2004

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Air Pollution
U.S. FDA Resources

Information from the National Library of Medicine

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Ages Eligible for Study:   up to 90 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
The sample population consists of cardiac patients with implanted cardioverter defibrillator devices attending device clinics at the New England Medical Center (NEMC) Cardiac Electrophysiology and Pacemaker Laboratory. All patients with implanted ICD devices with event time and date recording living in the greater Boston area will be included.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00015574

United States, Massachusetts
New England Medical Center, Cardiac Arrhythmia Service
Boston, Massachusetts, United States, 02111
Sponsors and Collaborators
National Institute of Environmental Health Sciences (NIEHS)
Tufts Medical Center
Study Director: Douglas Dockery, ScD Harvard School of Public Health

ClinicalTrials.gov Identifier: NCT00015574     History of Changes
Other Study ID Numbers: 9825-CP-002
First Posted: April 23, 2001    Key Record Dates
Last Update Posted: September 4, 2006
Last Verified: September 2006

Keywords provided by National Institute of Environmental Health Sciences (NIEHS):
air pollution
time series