Air Pollution and ICD-Detected Cardiac Arrhythmias

流行病学研究发现，颗粒物空气污染的短期增加与心血管发病率和死亡率之间存在关联。我们的计划项目目标是了解颗粒物污染与临床、生理和生化终点的关系，以反映这些关联的潜在机制。在本研究项目中，我们关注的是受自主调节影响的终端。我们发现，短期暴露于环境空气污染与植入心脏复律除颤器(ICD)的患者发生室性心律失常的风险增加有关。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诊断能力的改进增加了他们的 对这类研究的效用。大多数目前的ICD都有双腔监测，允许对室性和房性快速性心律失常进行更具体的定义。越来越多的冠状动脉再同步治疗ICD设备被植入充血性心力衰竭患者，这是一个特别容易死于心律失常的群体。我们建议招募400名波士顿地区的双腔ICD患者，这些患者在塔夫茨-新英格兰医疗中心接受随访。我们将对这些患者进行平均三年的前瞻性跟踪，记录确认的急性室性和室上性快速性心律失常的发作，并提高对 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前几小时和几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通过改进对暴露的空间和时间差异的评估，来表征颗粒物成分的不同影响。最后，我们将评估这种风险在易感亚组中是否更大，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.