Effect Of Left Ventricular Longitudinal Function On The Formation Of Left Atrial Appendage Thrombus In Patients With Atrial Fibrillation

Objective:Atrial fibrillation (AF) is one of the most common tachyarrhythmia in clinical practice. Electrical and structural remodeling of left atrium and (or) ventricle remodeling as well as hemodynamic disorder may induce heart failure (HF). Thrombosis is the main reason for the death and disability in patients with AF. And the deterioration of cardiac function is one of the most crucial risks increasing the incidence of AF and thrombogenesis. Echocardiography is useful in evaluation of left ventricular function in clinical practice, however, it is not clear that the relationship between left ventricular longitudinal function of AF patients with preserved ejection fraction and formation of left atrial appendage (LAA) thrombus. Recently studies have found the effect of radiofrequency ablation(RFCA) on a degree of improvement of left heart function in patients with AF and HF. But whether the change in left ventricularb function after RFCA in AF patients with preserved left ventricular ejection fraction is not clear. We aimed to assess the influence of left ventricular long-axis diastolic and systolic function on the formation of LAA thrombus and of RFCA on left ventricular long-axis diastolic and systolic function in patients with AF by tissue doppler imaging(TDI).Methods:Ninety patients whose left ventricular ejection fraction (LVEF)≥55%with AF in hospital were enrolled. Exclusion criteria included:heart valvular desease, mitral valve replacement, cardiomyopathy, implantation of pacemaker, constrictive pericarditis, pericardial effusion, pulmonary hypertension, hyperthyroidism, seriously hepatic insufficiency and renal insufficiency. These patients were divided into2groups according to examining LAA thrombus or spontaneous echo contrast (SEC) with transesophageal echocardiography (TEE),50patients without LAA thrombus and40patients with LAA thrombus/SEC. Patients in LAA thrombus/SEC groups were divided into2subgroups according to The duration of AF,12patients in paroxysmal AF and28patients in persistent AF. Routine parameters of left heart were measured by transthoracic echocardiography (TTE), like left atrial diameter (LAD) and LVEF. We estimated the ratio (E/Em) of early diastolic transmitral flow velocity (E) to mitral annular velocity (Em) and systolic mitral annular velocity (Sm) via pulse wave doppler and tissue doppler imaging (TDI) on TTE. The above ultrasonic cardiogram(UCG) parameters of left heart were measured1day before and3months after RFCA in patients without LAA thrombus. Comparing the differences of parameters between without LAA thrombus and with LAA thrombus/SEC groups, as well as paroxysmal AF and persistent AF subgroups, before and after RFCA in without LAA thrombus group in patients.Results:There were no significant difference in age, gender, hypertension, diabetes, stroke history, body mass index (BM1), Serum creatinine, LVEF(p>0.05). The ventricular rate in without LAA thrombus group was higher than those in LAA thrombus/SEC group (p<0.05). The values of LAD, E and E/Em were higher in LAA thrombus/SEC group than those in without LAA thrombus group, while Em and Sm were the opposite (p<0.05). The values of E and E/Em were higher in persistent AF subgroup than those in paroxysmal AF subgroup, while LVEF, Em and Sm were the opposite(p<0.05). There was no significant difference between the two subgroups in LAD(p>0.05). The values of LVEF, Sm were higher in without LAA thrombus group after RFCA than before, while LAD, E and E/Em were the opposite(p<0.05). There was no significant difference between before and after RFCA in Em(p>0.05).Conclusion:Values of left ventricular longitudinal function in AF patients with LAA thrombus/SEC group and without LAA thrombus group are both decreased, and compared with paroxysmal AF subgroup, left ventricular longitudinal function is reduced significantly in persistent AF subgroup. Left ventricular longitudinal function could improve after RFCA. UCG could be used to evaluate left ventricular longitudinal function in patients with AF, so that we could have a correct understanding of fully left ventricular function.