Recorded presentation

Wayne E. Cascio, MD, FACC, FAHA, Department of Medicine, Brody School of Medicine at East Carolina University, PCMH 378-TA, Greenville, NC 27834, 252-744-0083, casciow@mail.ecu.edu

As many as 60,000 excess deaths are estimated to occur annually in the U.S. secondary to exposure to particulate air pollution. Epidemiological studies indicate that acute and chronic exposures to airborne particulate matter (PM) are positively associated with increased cardiovascular mortality. Acute exposure to PM increases the risk cardiovascular events and hospitalization for arrhythmia, myocardial infarction and congestive heart failure. The association between PM and health effects does not show a threshold effect. Even small rises in the concentration of PM increase mortality. Those with heart disease particularly the elderly having diabetes, arrhythmia, conduction abnormalities and heart failure are especially susceptible to the adverse effects of inhaled PM. Yet, the mechanism accounting for the association between the level of ambient PM and the risk for cardiac events is unknown. Accumulating evidence suggests that fine particles from combustion sources rich in metal have a particularly important role in causing cardiovascular responses. Ongoing investigation utilizing epidemiological methods, human exposures, animals, and heart and vascular cells are rapidly increasing our understanding of the role of PM in cardiovascular health. Several mechanisms are proposed to account for the cardiovascular effects. These include increased risk of plaque rupture and thrombosis as well as ventricular arrhythmia. Such health outcomes appear to be driven by pro-inflammatory responses and altered neural input to the heart with attendant effects on thrombosis/fibrinolysis and electrophysiological properties. In summary, PM affects cardiovascular health, and the elderly are particularly vulnerable. The elderly need to be educated about PM’s effects to limit their risk.

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