Left Atrial Appendage Function and Stroke Risk.
Left Atrial Appendage Function and Stroke Risk.
复制标题
DOI：
10.1161/strokeaha.115.011273
复制
发表时间：
2015-12
期刊：
影响因子：
8.3
通讯作者：
Kamel H
中科院分区：
文献类型：
--
作者：
Yaghi S;Song C;Gray WA;Furie KL;Elkind MS;Kamel H
LAA 是胚胎左心房的残余物，而壁光滑的左心房则起源于原始肺静脉及其分支。 LAA 在很大程度上被认为是无功能的。然而，左心耳是一个主动收缩的结构，脉冲多普勒超声心动图上看到的流速波形及其突出的肌肉小梁就证明了这一点。 19 此外，左心耳可能在调节左心房压力方面发挥作用。研究表明，左心耳比左心房更容易扩张，并且左心耳内含有相对较高浓度的心房钠尿因子。 20, 21 因此，左心耳可能通过牵张敏感受体的激活和心房钠尿因子的作用来维持左心房压力，从而增加心率、利尿和尿钠排泄。 19 无论其最初的功能如何，左心耳长期以来一直被认为是 AF 患者血栓形成的主要部位。在一项纳入 317 名 AF 且最近发生栓塞事件的患者的经食管超声心动图 (TEE) 研究中，约 20% 有血栓证据，所有血栓均位于左心耳。 22 另一项对 23 项研究进行的汇总分析，包括 4792 名接受经食管超声心动图、心脏手术或尸检的 AF 患者，约 14% 的患者检测到左心房血栓，其中大多数发生在左心耳。 23 在本次综述中的几乎所有报告中，左心耳是大多数患者的血栓部位。 24 因此，使用各种成像方式更好地了解左心耳的解剖学和生理学可能有助于增进我们对中风发病机制的理解。 25
The LAA is the remnant of the embryonic left atrium, whereas the smooth-walled left atrium originates from the primordial pulmonary vein and its branches. The LAA is largely considered to be nonfunctional. However, the LAA is an actively contracting structure, as demonstrated by flow velocity waveforms seen on pulse Doppler echocardiography and by its prominent muscular trabeculations. 19 In addition, the LAA may play a role in modulating left atrial pressure. Studies have demonstrated that the LAA is more distensible than the left atrium, and a relatively high concentration of atrial natriuretic factor is contained within the LAA. 20, 21 Therefore, the LAA may maintain left atrial pressure through the activation of stretch-sensitive receptors and the actions of atrial natriuretic factor, which increases heart rate, diuresis, and natriuresis. 19 Regardless of its original function, the LAA has long been considered to be a prime site for thrombus formation in patients with AF. In a transesophageal echocardiography (TEE) study that included 317 patients with AF and a recent embolic event,≈ 20% had evidence of thrombus, all of which were in the LAA. 22 Another pooled analysis of 23 studies that included 4792 patients with AF who underwent transesophageal echocardiogram, cardiac surgery, or autopsy, left atrial thrombi were detected in≈ 14% of patients, and the majority of these occurred in the LAA. 23 In almost all reports included in this review, the LAA was the site of thrombi in most patients. 24 Therefore, a better understanding of the anatomy and physiology of the LAA using various imaging modalities may be of value in advancing our understanding of stroke pathogenesis. 25