In patients with myocardial infarction involving a sufficient amount of the left ventricle, increased left ventricular myocardial dysfunction causes elevated filling pressure, causing left atrial (LA) hypertension, which begets LA enlargement (LAE), which begets atrial fibrillation (AF), as shown across the top portion of Figure 1. A somewhat different causative pathway (Figure 1) entails ischemic mitral regurgitation (MR) resulting from apical tethering of mitral leaflets (2,3). This also leads to LA hypertension and LA enlargement, and to the same cascade, leading to AF. Obviously, coronary patients may have both of these pathways (e.g., in ischemic MR with left ventricular dysfunction). This second causative pathway is a commonly assumed mechanism wherein AF results from nonischemic MR. Maybe a patient cannot have pathway 2 without also having pathway 1.

中文翻译：

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心房心肌梗塞

在左心室受累的心肌梗塞患者中，左心室心肌功能障碍增加导致充盈压升高，引起左心房（LA）高血压，从而引起左心室扩大（LAE），进而引起心房颤动（AF），如图所示穿过图 1 的顶部。一个稍微不同的致病途径（图 1）需要由二尖瓣瓣叶 (2,3) 的顶端栓系导致的缺血性二尖瓣关闭不全 (MR)。这也会导致 LA 高血压和 LA 扩大，并导致相同的级联反应，导致 AF。显然，冠状动脉患者可能同时具有这两种途径（例如，在伴有左心室功能障碍的缺血性 MR 中）。第二种致病途径是一种普遍假设的机制，其中 AF 是由非缺血性 MR 引起的。