AIR POLLUTION AND IMPLANTABLE CARDIOVERTER DEFIBRILLATORS

基于人群的研究表明，在注射重悬颗粒、吸入重悬颗粒或环境中浓度较高的颗粒后，心血管死亡率和发病率增加，心电图（EKG）发生亚临床变化。已有心血管疾病的患者尤其容易对空气微粒污染发作产生急性反应。植入式心律转复除颤器（ICD）设备监测和识别心律失常，并在心律失常超过预定义阈值时启动治疗干预。这些事件的日期和时间连同触发治疗干预的事件的心电图记录一起被存储起来。我们将提取波士顿地区患者的这些数据，以产生按日期计算的心律失常数量和类型的指数。然后将心律失常事件的计数与微粒和气体空气污染以及在社区环境监测点收集的其他环境数据进行比较。环境颗粒物空气污染的特征将包括PM10和PM2.5的质量浓度、硫酸盐、硝酸盐和元素浓度。包括一氧化碳、二氧化氮、臭氧和二氧化硫在内的气体污染物的浓度将被测量，并被认为是心律失常的替代预测指标。包括温度、湿度和气压在内的气象因素将被认为是心律失常的独立预测因素，也是空气污染关联的混杂因素。这项研究将提供定量的暴露-反应函数，将特定颗粒的特征与心律失常的风险联系起来，心律失常是急性心血管衰竭和猝死的前兆。

Population based studies have shown increased cardiovascular mortality and morbidity shown subclinical changes in electrocardiograms (EKG) after instillation of resuspended particles, and on inhalation of resuspended particles or of concentrated ambient particles. Patients with pre-existing cardiovascular disease are particularly at risk for acute response to particulate air pollution episodes. Implantable cardioverter defibrillators (ICD) devices monitor and identify heart arrhythmias and initiate therapeutic interventions when arrhythmias exceed predefined thresholds. The date and time of these events are stored, along with electrocardiographic recordings of the events triggering therapeutic interventions. We will abstract these data for Boston area patients to produce indices of the number and types of arrhythmias by date. Counts of arrhythmic events will then be compared to particulate and gaseous air pollution and other environmental data collected at community based ambient monitoring sites. Characteristics of ambient particulate air pollution will include mass concentrations of PM10 and PM2.5, sulfate, nitrate and elemental concentrations. Concentrations of gaseous pollutants including carbon monoxide, nitrogen dioxide, ozone, and sulfur dioxide will be measured and considered as alternative predictors of cardiac arrhythmias. Meteorological factors including temperature, humidity, and barometric pressure will be considered as independent predictors of arrhythmias, and as confounders of the air pollution associations. This study will provide quantitative exposure-response functions relating specific particle characteristics to the risk of cardiac arrhythmias, a precursor of acute cardiovascular failure and sudden death.