Particulate Air Pollution Triggers Ventricular Arrhythmias:

TM6-O-03 Introduction: Air pollution studies have demonstrated links between air pollution levels, mortality, and morbidity in cardiovascular causes. More specifically, air pollution concentrations have been reported to be associated with short term effects on autonomic control of the heart, possibly leading to sudden death. Earlier studies have been performed in Boston and Vancouver investigating the association between short term increases in air pollution levels and ventricular arrhythmias in patients with implantable cardioverter defibrillators, although with conflicting results. This study was designed to further elucidate the possible short-term association between air pollution and the onset of potentially life-threatening ventricular arrhythmias. Methods: We included 179 patients with implantable cardioverter defibrillators from 2 different cities, between 2001 and 2005. Individual patient data regarding medical conditions were collected and information was downloaded from the devices concerning type of arrhythmia, time of event, and type of electrotherapy administered. In addition, arrhythmia diagnosis was confirmed by an electrophysiologist using the electrocardiograms stored in the devices. Continuous air pollution data from urban background stations were aggregated into hourly means. Using a case-crossover design, we analyzed the temporal relation between ventricular arrhythmia episodes leading to therapy and preceding 3-hour mean air pollution levels. The endpoint of a case period was derived using the time and date of the arrhythmic event. Each case period was matched with several control periods defined by the same time period on all other same-day-of-week days of the same calendar month. Results: Hourly PM10 was on average 21 μg/m3 (SD, 14 μg/m3) and 18 μg/m3 (SD, 13 μg/m3) for the 2 cities, respectively. From the 179 included patients, 93 ventricular arrhythmias were obtained from 61 patients during the study period. For these events, our preliminary results show an association between a preceding 3-hour running mean and a following ventricular arrhythmia for PM10 (odds ratio = 1.26; 95% CI, 0.97–1.66), for a 10-μg/m3 increase. For carbon monoxide and nitrogen dioxide, an association in the same direction was found and when examnining a 24-hour moving average similar associations were found for all pollutants. Conclusions: These results add evidence to suggest that elevated levels of particulate air pollution are associated with the onset of potentially life-threatening ventricular arrhythmias leading to electroconversion treatment in patients with implanted cardioverter defibrillators.