Air pollution raises risk for dangerous arrhythmias among people with ICDs

Roman Bystrianyk · medicine forum Guru Joined: 02 May 2005 Posts: 454

"Air pollution raises risk for dangerous arrhythmias among people with
ICDs", Medical News Today, June 2, 2005,
Link: http://www.medicalnewstoday.com/medicalnews.php?newsid=25476

Researchers from the Harvard School of Public Health and colleagues
from Boston area medical institutions have linked short term high
pollution concentrations with an increased incidence of irregular and
very dangerous heart arrhythmias among a group of cardiac patients from
the greater Boston area who had implanted cardioverter defibrillators
(ICD). The findings appear in the June 1, 2005 issue of Environmental
Health Perspectives.

"Particulate pollution and gaseous pollution from automobiles, diesel
engines and power plants have long been associated with causing serious
problems for people with heart conditions," said Doug Dockery, lead
author of the study and professor of environmental epidemiology at the
Harvard School of Public Health. He continued, "In this study we wanted
to see if there's an increased risk of ventricular tachyarrhythmias, a
very dangerous and rapid beating of the heart which can lead to sudden
cardiac arrest. We monitored a group of Boston area residents at high
risk of sudden cardiac death if not for their implanted
defibrillators."

Between 1995 and 2002 the researchers monitored 203 Boston area
patients from the Tufts University New England Medical Center who had
implanted cardioverter defibrillators for episodes of tachyarrhythmias.
Information on arrhythmias was recorded in the ICDs and retrieved
during the patients' regular clinical follow-up visits. Air pollution
levels were measured at up to10 sites in the Boston metropolitan area
for ozone, carbon monoxide, sulfur and nitrogen dioxide and at the
Harvard School of Public Health for fine particles.

The researchers found a significant association of air pollution with
an increased risk of ventrical tachyarrhythmias among patients who had
experienced any kind of arrhythmia three days prior to the episode,
particularly when levels of particulate air pollution, black carbon,
nitrogen dioxide (all linked with motor vehicle emissions) and sulfur
dioxide (linked to power plants) were present. The finding suggests
that air pollution provokes ventricular tachyarrhythmias among people
with acutely predisposed conditions. The researchers calculated that
the ICD patients had a risk of potentially life threatening ventricular
tachyarrhythmias linked with fine particulate pollution five times
higher for risk of cardiovascular death than the people in the general
public. For the highest risk patients, those with a recent ventricular
arrhythmia episode, the increased risk for a new ventricular
tachyarrhythmias was 97 percent for each 10 microgram per cubic meter
increase of particulate pollution.

Dockery added, "What we found suggests that air pollution may act in
combination with electrical instability of the heart to increase the
risk for ventricular tachyarrhythmias. The data that ICDs collect on
episodes of arrhythmias provides a significant resource for
understanding the role of air pollution in triggering these events."

The research was supported by grants from the Health Effects Institute
and the National Institute of Environmental Health Sciences.

Harvard School of Public Health is dedicated to advancing the public's
health through learning, discovery, and communication. More than 300
faculty members are engaged in teaching and training the 900-plus
student body in a broad spectrum of disciplines crucial to the health
and well being of individuals and populations around the world.
Programs and projects range from the molecular biology of AIDS vaccines
to the epidemiology of cancer; from risk analysis to violence
prevention; from maternal and children's health to quality of care
measurement; from health care management to international health and
human rights. For more information on the school visit:
http://www.hsph.harvard.edu

Contact: Kevin C. Myron
kmyron@hsph.harvard.edu
617-432-3952
Harvard School of Public Health
http://www.hsph.harvard.edu

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