Objective The aim of the present study is to evaluate the

Objective The aim of the present study is to evaluate the association of air pollution with the onset of atrial fibrillation (AF). carbon sulfate particle number NO2 SO2 and O3 in the 24 hours prior to the arrhythmia was examined utilizing a case-crossover analysis. In sensitivity analyses associations with air pollution between 2 and 48 hours prior to the AF were examined. Results Of 176 patients followed for an average of 1.9 years 49 patients had 328 episodes of AF lasting ≥ 30 seconds. Positive but nonsignificant associations were found for PM2.5 in the prior 24 hours but stronger associations were found with shorter exposure windows. The odds of AF increased by 26% (95% CI 8% to 47%) for each 6.0 μg/m3 increase in PM2.5 in the 2 2 hours prior to the event (p=0.004). The odds of AF was highest at the upper quartile of mean PM2.5. Conclusion Particulate matter was associated SB590885 with increased odds of AF onset within hours following exposure in patients with known cardiac disease. Air pollution is an acute induce of AF likely contributing to the pollution-associated adverse cardiac outcomes observed in epidemiological studies. monitoring of atrial arrhythmias over an extended period of SB590885 follow-up. Associations with traffic related and other air pollutants in the 24-hours prior to an AF event are evaluated as well as alternative air pollution exposure windows relative to AF onset. METHODS Patient populace Subjects were recruited between September 2006 and March 2010 from patients followed at the Tufts Medical Center Cardiac Arrhythmia Center. Inclusion criteria included prior implantation of a dual (atrial and ventricular) chamber ICD and residential zip codes within a 50-kilometer radius of the Harvard Supersite air quality monitoring station. Exclusions included age younger than 18 years chronic AF lack of follow-up at Tufts Medical Center terminal illness or inability to give informed consent. The study protocol and informed consent were approved by the Institutional Review Board at Tufts Medical Center and the Harvard School of Public Health. At the initial visit all patients completed an interviewer-administered questionnaire including socio-demographic characteristics medical history detailed medication way of life and smoking history. They were measured for height and weight. A comprehensive past and current medical history based on the National Cardiovascular Disease Data ICD Registry form was filled out by study coordinators based on review of medical records. Arrhythmias Patients were followed with either a clinic visit or by telephone every three months from study enrollment until June 30 2010 At these encounters ICD data which included the arrhythmia logbook and electrograms were downloaded directly or with trans-telephonic transmission and printed. All ICDs were dual chamber and capable of recording the date time and real time electrograms of atrial and ventricular events. In addition to documenting the arrhythmia the ICD characterizes each event as atrial or ventricular and as sustained or nonsustained and records the total time of each episode. Heart rate detection and treatment rates for ventricular SB590885 arrhythmias are programmed by the physician according to the specific needs of the patient. In general treatment for ventricular arrhythmia begins at heart rates above 160 beats per minute (bpm). In addition to documenting rapid ventricular ROBO4 episodes SB590885 these devices also document and store electrograms of rapid atrial arrhythmias even if the ventricular rate remains low. Arrhythmias documented by the ICD were later reviewed and interpreted by an electrophysiologist (MSL) blinded to air quality. These arrhythmias were characterized as ventricular sinus tachycardia AF atrial arrhythmia other than AF or not an arrhythmia. Sinus tachycardia is usually characterized by gradual onset and a 1 to 1 1 atrial to ventricular association. Acute onset atrial arrhythmias were subdivided into AF and atrial arrhythmias other than AF. These arrhythmias generally do not have 1 to 1 1 atrial SB590885 to ventricular association; typically the atrial rate is much faster than the ventricular rate. Irregular rapid atrial electrograms were classified as AF (Physique 1). Physique 1 Electrocardiogram of atrial fibrillation We restricted our analyses to clinically relevant AF defined as those lasting 30 seconds or.