دانلود رایگان مقاله اختلال عملکرد زائده دهلیز چپ با ریتم سینوسی

Abstract

Background: Trans-esophageal echocardiogram (TEE) is a gold standard test for diagnosis of left atrial (LA) appendage function. Aim: To evaluate left atrial appendage (LAA) dysfunction using mitral annular systolic velocity measured by tissue Doppler imaging “Sm” in acute embolic stroke young patients with sinus rhythm. Methods: Transthoracic (TTE) and transesophageal echocardiography (TEE) were performed in 70 consecutive patients with sinus rhythm without obvious left ventricular dysfunction within 2 weeks after embolic stroke. Two groups were identified: LAA dysfunction [LAA emptying peak flow velocity (LAA-eV) <0.55 m/s, n Z 28, age 52
11 years] and without LAA dysfunction (LAA-eV 0.55 m/s, n Z 42, age 54
10 years) on TEE. Tissue Doppler mitral annular systolic velocity “Sm” was obtained in apical four chambers view on TTE and D-dimer level estimated for all patients. Results: Sm was significantly lower in patients with than in those without LAA dysfunction (P < 0.0001). There was a significant correlation between Sm, LAVI, LAEF%, E/A ratio and LAA-eV in all selected patients groups. The optimum cut-off value of Sm for predicting LAA dysfunction was below or equal 8 cm/s (sensitivity 89.6% and specificity 94.2%). Conclusion: Tissue Doppler mitral annular systolic velocity is an independent non-invasive easy predictor of LAA dysfunction and significantly correlated with LAA-eV (p < 0.0001) in acute embolic stroke young patients with sinus rhythm.

Discussion

It is well known that TEE parameters for evaluating LAA dysfunction can predict LAA thrombus formation.9e11The presence of spontaneous echo contrast and low LAA eV was reported to be reliable markers for stratifying patients with AF for the risk of thromboembolism.10 In addition, TTE parameters such as increased LAD, decreased LA fractional shortening, and increased trans-mitral inflow velocities (E/ A) were useful predictors for LAA thrombus. However their predictive values for detecting LAA thrombus were much lower than those of TEE parameters.24,25 Recently, studies reported that left atrial wall velocity “LAWV” as measured by TTE can be used to stratify patients with AF for the risk of cardiac stroke.26,27 However, LAWV cannot necessarily be accurately measured because of the inherent angle dependence. LA peak systolic strain may be a more sensitive parameter than LAWV. It is known that there are three types of LA mechanical function: reservoir, conduit and booster pump function.28