Air Pollution and ICD-Detected Cardiac Arrhythmias

流行病学研究发现，空气颗粒污染的短期增加与心血管疾病发病率和死亡率之间存在关联。我们的项目目标是了解颗粒污染与临床，生理和生化终点的关系，反映这些关联的潜在机制。在这个研究项目中，我们专注于受自主调节影响的端点。我们发现，短期暴露于环境空气污染与植入心律转复除颤器（ICD）患者室性心律失常风险增加相关。虽然这项研究最初并不是为了检测室上性心律失常，但我们发现这些事件的风险也与空气污染事件有关。ICD诊断能力的提高增加了他们的 这类研究的实用性。大多数当前ICD具有双腔监测，允许更具体地定义室性与房性快速性心律失常。越来越多的冠状动脉复苏治疗ICD设备被植入充血性心力衰竭患者，这是一个特别容易因心律失常而猝死的群体。我们计划入组400例在Tufts-New England Medical接受随访的波士顿地区双腔ICD患者。我们将对这些患者进行平均3年的前瞻性随访，记录经证实的急性室性和室上性快速性心律失常的发作， 我们的心律失常结果使用病例交叉方法，我们将评估室性和室上性快速性心律失常与这些心律失常发生前数小时和数天内环境空气污染浓度的风险。加强污染暴露监测将使我们能够表征颗粒成分的不同影响，改善对暴露的空间和时间差异的评估。最后，我们将评估这种风险是否在易感亚组中更大，包括全身炎症升高、迷走神经张力降低或诊断为充血性心力衰竭的患者。

Epidemiologic studies have found an association between short-term increases in particulate air pollution and cardiovascular morbidity and mortality. Our Program Project goal is to understand the relation of particle pollution to clinical, physiologic and biochemical endpoints reflecting potential mechanisms underlying these associations. In this Research Project we have focused on endpoints influenced by autonomic regulation. We have found that short-term exposure to ambient air pollution is associated with increased risk of ventricular arrhythmias in patients with Implanted Cardioverter Defibrillators (ICD). Although the study was not originally designed to detect supraventricular arrhythmias, we found the risk of these events also was associated with air pollution episodes. Improvements in ICD diagnostic capabilities have increased their utility for such studies. Most current ICDs have dual chamber monitoring, allowing more specific definition of ventricular versus atrial tachyarrhythmias. A growing number of Coronary Resynchronization Therapy ICD devices are being implanted in congestive heart failure patients, a group particularly susceptible to sudden death from arrhythmias. We propose to enroll 400 Boston area patients with dual chamber ICDs being followed at Tufts-New England Medical. We will prospectively follow these patients for an average of three years recording confirmed episodes of acute ventricular and supraventricular tachyarrhythmias, with improved definition of our arrhythmia outcomes. Using case-crossover methods, we will assess the risk of ventricular and supraventricular tachyarrhythmias with ambient air pollution concentrations in the hours and days prior to these arrhythmias. Enhanced pollution exposure monitoring will enable us to characterize differentiate effects of particle components, with improved assessment of spatial as well as temporal differences in exposure. Finally, we will assess if this risk is greater in susceptible subgroups including patients with elevated systemic inflammation, depressed vagal tone, or a diagnosis of congestive heart failure.