Arrigo F, Carerj S, Pizzimenti G
Istituto Pluridisciplinare di Clinica Medica, Università degli Studi, Messina.
Cardiologia. 1993 Dec;38(12 Suppl 1):301-17.
In the total population, cerebrovascular ischemic diseases account for 0.2-0.3% cases per year, and in the 20-40% of them it is possible to recognize a cardioembolic mechanism. The cardiological examination in patients with stroke is, therefore, aimed at detecting cardiac sources of emboli (left atrial, valvular, and ventricular thrombosis, atherosclerotic plaques of ascending aorta), and at identifying the cardiovascular disease directly or indirectly associated with ischemic stroke. Transesophageal echocardiography (TEE) is particularly suitable for this purpose, due to the proximity of the transducer to the posterior cardiac structures and to its better resolution. Many recent reports have demonstrated that TEE not only improves the recognition of known cardioembolic diseases (intracardiac thrombi, mitral stenosis, valvular prosthesis thrombosis, endocardial infectious diseases), but is also the most reliable non invasive technique suitable to detect atherosclerotic lesions of the ascending aorta. Furthermore, TEE allowed to recognize new anatomic and functional abnormalities, such as left atrial spontaneous echo contrast, atrial septal aneurysm, patent foramen ovale, frequently associated with stroke. Noteworthy, TEE is the only technique suitable for functional and anatomic evaluation of the left atrial appendage. The Authors studied by TEE the functional properties of left atrial appendage in patients with severe mitral stenosis with or without atrial fibrillation, as compared to patients with left atrial thrombosis. Results showed that fractional shortening of left appendage was greatly reduced, at the same extent in the 3 groups, demonstrating that abnormalities in left atrial appendage emptying could be a risk factor for atrial thrombosis. In order to compare TEE with the transthoracic 2D-echo for the detection of cardioembolic sources, the Authors studied 63 patients with ischemic stroke. TEE revealed a possible cardioembolic source in 70% of younger patients and in 50% of patients older than 45 years. These abnormalities were detected by TEE respectively in 10% and in 1.8% of cases. These data are in agreement with many other reports in literature, and suggest the usefulness of TEE in the evaluation of patients with ischemic stroke and no evidence of severe atherosclerotic cerebrovascular disease, in contrast to the poor role of TEE. Another important field is the prevention of stroke in patients at high risk of cardioembolic events. The role of TEE before and immediately after cardioversion in patients with atrial fibrillation has been recently studied by several papers. Cardioversion was proved at low risk of stroke when TEE did not show left atrial or left appendage thrombosis. Therefore, the transesophageal approach identifies patients needing prolonged anticoagulation (roughly 20%), avoiding an undue, potentially dangerous therapy.
在总人口中，每年脑血管缺血性疾病的发病率为0.2 - 0.3%，其中20 - 40%的病例可识别出心源性栓塞机制。因此，对中风患者进行心脏检查旨在检测栓子的心脏来源（左心房、瓣膜和心室血栓形成，升主动脉粥样硬化斑块），并识别与缺血性中风直接或间接相关的心血管疾病。经食管超声心动图（TEE）特别适合于此目的，因为换能器靠近心脏后部结构且分辨率更高。许多近期报告表明，TEE不仅能提高对已知心源性栓塞疾病（心内血栓、二尖瓣狭窄、人工瓣膜血栓形成、心内膜感染性疾病）的识别率，而且是检测升主动脉粥样硬化病变最可靠的非侵入性技术。此外，TEE还能识别新的解剖和功能异常，如左心房自发显影、房间隔瘤、卵圆孔未闭，这些异常常与中风相关。值得注意的是，TEE是唯一适用于对左心耳进行功能和解剖评估的技术。作者通过TEE研究了重度二尖瓣狭窄伴或不伴房颤患者与左心房血栓形成患者左心耳的功能特性。结果显示，三组患者左心耳的缩短分数均大幅降低，表明左心耳排空异常可能是心房血栓形成的危险因素。为了比较TEE与经胸二维超声心动图在检测心源性栓塞来源方面的效果，作者对63例缺血性中风患者进行了研究。TEE显示，70%的年轻患者和50%的45岁以上患者可能存在心源性栓塞来源。经胸二维超声心动图分别在10%和1.8%的病例中检测到这些异常。这些数据与文献中的许多其他报告一致，表明TEE在评估无严重动脉粥样硬化性脑血管疾病证据的缺血性中风患者中有用，而经胸二维超声心动图的作用较差。另一个重要领域是预防心源性栓塞事件高危患者的中风。近期有几篇论文研究了房颤患者在心脏复律前后TEE的作用。当TEE未显示左心房或左心耳血栓形成时，证明心脏复律的中风风险较低。因此，经食管途径可识别需要长期抗凝治疗的患者（约20%），避免不必要且可能危险的治疗。
