Haze & Your Heart

Hi everyone who has to put up with the haze the last few weeks,
Do be careful if you have had heart attacks before.

Air Pollution Can Induce Arrhythmias (irregular heart beat) in Some MI Patients
From Reuters Health Information

Aug 07 - A history of myocardial infarction can increase the risk of ventricular arrhythmias when patients are exposed to airborne particulate matter, according to Italian researchers. Failure to take beta-blockers appears to make these patients more prone to autonomic dysregulation.

As reported in the July issue of the European Heart Journal, Dr. Antonio F. Folino of the University of Padua and colleagues assessed the impact of air pollution on arrhythmias and autonomic function in 39 patients with a prior myocardial infarction.

"We accurately assessed the exposure to air pollution...by means of personal samplers worn by the subjects in backpacks for 24 hours, analyzing the particulate matter to which they were exposed," Dr. Folino told Reuters Health.

At the same time as air pollution monitoring, all of the subjects underwent continuous ECG recording. Thirty-two of the patients were taking beta blockers.

Overall, there was no correlation between heart rate variability and exposure to particulate matter. However, there was a negative correlation between heart rate variability and exposure to PM-0.25 in the patients not taking beta-blockers. More severe ventricular arrhythmias were observed at the highest concentrations of PM-10 and PM-2.5.

"We showed a direct negative influence of particulate matter on the cardiovascular system," Dr. Folino said. "In particular, the inhalation of the larger particles has been correlated with increased arrhythmias, while the ultrafine (particles) induced an increase in sympathetic autonomic activity, a negative factor in the prognosis of patients with heart disease."

These results, he concluded, show that "patients with coronary artery disease are particularly vulnerable to the effect of air pollution and that the effects of air pollutants can worsen the prognosis of these subjects."

Eur Heart J 2009;30:1614-1620.