AIR POLLUTION AND IMPLANTABLE CARDIOVERTER DEFIBRILLATORS

基于人群的研究表明，心血管死亡率和发病率增加，在滴注再悬浮颗粒物、吸入再悬浮颗粒物或浓缩环境颗粒物后，心电图(EKG)出现亚临床变化。既往有心血管疾病的患者尤其有可能对颗粒性空气污染事件做出急性反应。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阈值时启动治疗干预。这些事件的日期和时间与触发治疗干预的事件的心电图记录一起存储。我们将为波士顿地区的患者提取这些数据，以便按日期生成心律失常的数量和类型的指数。然后，心律失常事件的计数将与在社区环境监测点收集的颗粒物和气体空气污染以及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。将测量包括一氧化碳、二氧化氮、臭氧和二氧化硫在内的气体污染物的浓度，并将其视为心律失常的替代预测指标。包括温度、湿度和大气压在内的气象因素将被视为心律失常的独立预测因素，并被视为空气污染关联的混杂因素。这项研究将提供特定颗粒特征与心律失常风险之间的定量暴露-反应函数，心律失常是急性心血管衰竭和猝死的先兆。

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.