| BackgroundAtrial fibrillation (AF) is one of the most common arrhythmia, the prevalence increases with age, affecting about 10% of patients older than age 80, 42%-65% of patients with rheumatic heart disease mitral stenosis. Except the syndrome caused by AF itself, it can also cause cerebral embolism. 90% thrombus of AF are in left atrial appendage(LAA). There is 20% embolism in patients with atrial fibrillation, 14%patients with acute AF accompanied with LAA/LA thrombus, 27% in chronic patients and 40% in patients with mitral stenosis or patients embolism before. Early cardioversion and embolism prevention are more and more empshasied because of this . Blood can't be filled and emptied normallyin LA, especially in LAA in AF. It is said that LAA enlarges and the regularity of LAA flow disappears in AF. Left Pulmonary venous flow's (PVF) regularity changes in AF too. All blood velocities slow in AF. It seems that the changes of LAA and pulmonary venous structure and function can predict the thrombus, but these indexes can hardly be detected by transthoracic echocardiography (TTH). Transesophageal echocardiography (TEE) detects cardiac structure and hemodynamic physiology postero-anterior position by probe in oesophagus, it can manifest these structures because it can avoid the interference of air and sternum. Changes and relationships of PVF and LAA were evaluated in AF in this study ObjectiveChanges and relationships of PVF and LAA were evaluated by TEE in patients with AF. Patients and Methods69 patients (24 men and 45 women, mean age 50 years range from 28 to 75) with AF were examined by TEE in the first affliated hospital of Zhejiang University from 2002.5-2002.12, they were classified according with whether there was thrombus in LAA. 15 people (6 men and 9 women, mean age 48 ages range from 27 to 67) were enrolled as the matched controlled group, each one was proved no disease ofcardiovascular system by system health examination, laboratory examination, X ray, ECG and ultrasonic examination. Before the TEE evaluation, everyone in fasted state underwent a complete TTH study (two-dimensional, spectral pulsed and continuous wave Doppler, and color flow Doppler echocardiography) using a commercially available Doppler echocardiography unit (HPSONOS-5500) With a 2.5/2.0MHz phased-array transducer. Subsequently the TEE study was performed in each one after topical anesthesia of the hypopharynx with lidocaine, all studies were carried out by two experienced cardiologists using a 5.0/3.7 MHz transducer mounted at the end of a 100cm echoscope. The echoscope was advanced 25-32cm from the incisors allowed consistent imaging of the LAA and pulmonary venous at basal short-axis view. The total area of the LAA was measured with a trackball by tracing the endocardial borders of this triangular extension of the left atrial cavity, and the area was calculated by computed planimetry. The LAA maximal and minimal areas were determined by two observers. The width of the LAA was defined in each plane by the line from the confluence of the left upper pulmonary venous and the LAA to the outermost portion of the mitral annulus, the length of LAA was measured from this confluence to the appendage apex. LAA flow (LAA-Pev and LAA-Fil) velocity profiles were obtained with the pulsed Doppler sample volume immediatelyinside the appendage orifice. Pulmonary flow (AR, VR, VS, VD) were examined with the pulsed Doppler sample volume 0.5cm-1cm inside the left pulmonary venous orifice. When the patients were in the sinus rhythm, LAA maximal area and LAA-A, LAA-L were determined by the appearance of P wave on electrocardiogram and LAA minimal area was measured around the appearance of QRS complex; when in the atrial fibrillation, they were determined independent of the electrocardiogram, LAA-EF was calculated as (LAA-Max-LAA-Min)/LAA-Max. Maximum velocity of LAA flow and PVF were determined immediately prior to the QRS complex. Every index above was averaged 5 cardiac cycles in AF and 3 cardiac cycles in sinu... |
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