Atrial electrical remodeling due to chronic stretch: Defining the substrate for atrial fibrillation

背景：心力衰竭是一种常见的心脏疾病，主要表现为心脏的泵血功能明显减弱。二尖瓣反流是正常心脏收缩时血液从左心室（下心室）渗漏回左心房（上心室）的常见情况。这会对心脏造成压力，并可能导致心力衰竭。房间隔缺损是一种常见的先天性心脏病，可能要到成年后才能诊断出来。有几种形式，但最基本的问题是血液从左心房渗漏到右心房。这也会给心脏带来压力，导致心力衰竭。所有这三种情况都与心房颤动（AF）的风险显著增加有关。这种不正常的快速不规则的心律使心脏的泵送效率低下。患有心房颤动的人可能会感到呼吸急促、疲倦或心悸。房颤是中风和过早死亡的重要原因，是最常见的心律失常，在70岁以上人群中发生率高达10%。即使在修复了漏瓣膜或房间隔缺损后，发生这种心律的风险仍然很高。研究目的：本研究将试图了解为什么这些情况的患者有发生房颤的风险，以及为什么这种风险在手术矫正后可能持续存在（二尖瓣反流和房间隔缺损）。这项研究将利用复杂的新测绘技术来获得对这种非常常见但尚未了解的心律紊乱机制的原始见解。该研究有可能确定这些患者群体中房颤的原因，因此代表了我们对房颤机制的理解的一个量子进步。预期它将成为发展治疗和预防办法的基础。

Background: Cardiac failure is a common heart disorder in which the pumping function of the heart is significantly weakened. Mitral regurgitation is a common condition where there is a leakage of blood from the left ventricle (lower heart chamber) back into the left atrium (upper heart chamber) during normal cardiac contraction. This puts a strain on the heart and may cause heart failure. Atrial septal defect is a common form of congenital heart disease which may not be diagnosed until adulthood. There are several forms but the basic problem is leakage of blood from the left atrium into the right atrium .This also puts a strain on the heart and can cause heart failure. All 3 conditions are associated with a significantly increased risk of atrial fibrillation (AF). This abnormal fast irregular cardiac rhythm makes the pumping of the heart inefficient. People with AF may feel short of breath, tired, or develop palpitations. AF is an important cause of stroke and premature death and is the most common heart rhythm disturbance occurring in upto 10% of the over 70 age group. Even after repair of the leaky valve or atrial septal defect there is still a high risk of developing this rhythm. Purpose of the study: This study will try to understand why patients with these conditions are at risk of developing atrial fibrillation, and why this risk might persist after surgical correction when this is possible (mitral regurgitation and atrial septal defect). The study will utilise sophisticated new mapping techniques to gain original insights into the mechanism of this very common and as yet poorly understood heart rhythm disturbance. The study has the potential to determine the cause of atrial fibrillation in these patient groups and as such represent a quantum advance in our understanding of he mechanism of atrial fibrillation. It would be expected to form a foundation on which development of curative and preventative approaches may be based.