Stretch Induced Pulmonary Vein Remodelling: Implications for the Initiation and Maintenance of Atrial Fibrillation

心房颤动（AF）是影响人类的最常见的心律失常，发生在2%的成年人中。这是一种心脏顶部腔室的混乱节律紊乱，导致频繁住院治疗福尔斯、胸痛、心悸、心力衰竭和中风。此外，它还与死亡率增加有关。有证据表明肺静脉（PV;将血液从肺引流回心脏的静脉）在房颤的发生和维持中起着重要作用。然而，这些结构促进房颤的原因仍不清楚。诱发房颤的几种情况与心房牵张有关（如心力衰竭）。这些情况记录了心房内的异常，但肺静脉内发生的变化尚不清楚。甚至有人提出，在适当的易感患者中，由血流引起的搏动性牵拉可能足以触发AF。因此，已经进行了深入的研究，以确定肺静脉内发生的异常。在房颤患者中，肺静脉表现出与无房颤患者不同的电生理特性。然而，牵拉（一种常见的诱发因素）对肺静脉电生理特性的影响尚不清楚。通过消融术防止肺静脉与心脏相互作用的电活动，使我们有能力治愈房颤。然而，我们手术技术的进一步改进、防止这种心律失常发生的能力以及治疗房颤的非侵入性策略的发展，取决于对启动和维持这种情况的机制的更好理解。特别是，肺静脉内的电生理变化，使患者容易发展为房颤需要进行调查。这一系列的研究将评估急性和慢性拉伸对人类肺静脉的影响，以确定为什么这些结构会促进AF。

Atrial fibrillation (AF) is the most common heart rhythm disorder to affect humans, occurring in 2% of adults. It is a chaotic rhythm disorder of the top chambers of the heart that results in frequent hospitalization for falls, chest pain, palpitations, heart failure and stroke. In addition, it is associated with an increased mortality. Evidence suggests an important role of the pulmonary veins (PV; veins draining blood from the lungs back to the heart) in the initiation and maintenance of AF. However, why these structures promote AF remains unknown. Several conditions predisposing to the development of AF are associated with atrial stretch (such as heart failure). These conditions have documented abnormalities within the atria but the changes that occur within the PVs are unknown. It has even been suggested that pulsatile stretch, as caused by blood flow, in the appropriately predisposed patient, may be enough to trigger AF. As such there has been an intensive search to identify the abnormalities that occur within the PVs. In patients with AF, the PVs demonstrate distinctive electrophysiological properties compared to those without AF. However, the effect of stretch, a common predisposing factor, on the electrophysiological properties of the PV is not known. Preventing electrical activity from the PVs interacting with the heart by ablation has provided a glimpse at our ability to cure AF. However, further improvements in our procedural technique, the ability to prevent the occurrence of this rhythm disorder, and the development of noninvasive strategies to cure AF, hinges on the better understanding of the mechanisms initiating and maintaining this condition. In particular, the electrophysiological changes within the PVs that predispose patients to the development of AF need to be investigated. This series of studies will evaluate the effect of acute and chronic stretch on the PVs in humans to determine why these structures promote AF.