| Background and Objective Thromboembolism is the most popular complication of atrial fibrillation (AF) which is the most common sustained arrhythmia. Non-valvular atrial fibrillation (NVAF) accounts for 87% among all of AF. In guideline, rhythm control is not the first target for the patients with AF, and the ventricular rate control becomes an acceptable alternative. It appears especially important to prevent thromboembolism by evaluating the risk of embolism, screening high-risk patients and anticoagulation treatment. The previous studies showed some risk factors in thromboembolism, such as clinical risk factors, echocardiography index and blood thrombosis marker, unfortunately their clinical use is very limited for their technical difficulty and poor availability. In contrast, surface electrocardiogram is very popular in clinical practice. Previous studies revealed that the amplitude of fibrillatory wave correlated with the cause of AF and left atrial size and inferred there might be dependability between fibrillatory wave and thromboembolism. So, we hypothesized that the fibrillatory wave may be a good indicative for predicting thromboembolism. However, reports on the relationship are few. In the present study, we intend to explore the clinical value of fibrillatory wave for evaluation the risk of thromboembolism in patients with NVAF by measuring and analyzing of the amplitude, timing of fibrillatory wave and f-f interval in patients with NVAF. Patients and Methods 85 patients with NVAF were divided into 2 groups: fine AF group (n=57) and coarse AF group (n=28). Coarse AF was defined as any F waves with an amplitude equivalent to 1mm, and fine AF as F waves less than 1mm in amplitude. Then these 85 patients were classified into thromboembolic events group (n=26) and non-thromboembolic events group (n=59) according to the occurrence of thromboembolic events. All patients underwent transthoracic echocardiography to detect LAD, LVEDD and LVEF. A standard ECG in V1 lead was recorded at a special speed (50mm/s) and sensitivity (lmV/20mm). vWF, GMP-140 and D-dimer were determined with enzyme-linked immunosorbent assay (ELISA) and the AT-Ⅲactivity with spectrophotometric assay.Results (1) Enrolled 85 patients with NVAF. The age of fine AF was older than that of coarse AF (69.96±9.32 vs 61.75±13.57yrs, P<0.05). There were no significant differences in sex, AF duration, heart rate and underlying diseases between fine AF and coarse AF (P>0.05).(2) The incidence rate of thromboembolic events in fine AF(22/57) was higher than in coarse AF (4/28)(39% vs 14 %, P<0.05).(3) The timing of fibrillatory wave was significantly shorter in patients with fine AF (0.062±0.012 vs 0.074±0.016s, P<0.05), but no significant differences were found in the f-f interval,the frequency of fibrillatory wave and echocardiographic index (P>0.05). vWF was significantly higher in patients with fine AF than in those with coarse AF (119.72±59.45 vs 92.88±49.89%, P<0.05). There were no significant differences in GMP-140,DD and AT-Ⅲbetween fine AF and coarse AF (P>0.05).(4) In the thromboembolic events group (n=26, male 18, female 8), 17 were attacked by ischemic stroke; 4 transient ischemia attach; 5 peripheral artery embolism. The incidence of fine AF in the thromboembolic events group is significant higher than that in non-thromboembolic events group(85% vs 59%, P<0.05). There were no significant differences in sex, age, AF duration, heart rate and underlying disease between two groups (P>0.05).(5) The amplitude of fibrillatory wave was significantly smaller in the thromboembolic events group than that in non-thromboembolic events group(0.075±0.017 vs 0.096±0.038mV, P<0.05); f-f interval was shorter than the latter (0.116±0.009 vs 0.126±0.016s, P<0.05); and the frequency of fibrillatory wave was higher in the thromboembolic events group (536±90 vs 482±64bpm, P<0.05). But no significant differences were found in the timing of fibrillatory wave and echocardiography index between the two groups (P>0.05) .(6) GMP-140(15.33±4.82 vs 12.06±3.92ng/ml, P<0.05),D-dimer (0.69±1.36 vs 0.26±0.52μg/ml, P<0.05) and AT-Ⅲ(140.58±72.14 vs 107.46±53.61%, P< 0.05)were significantly higher in the thromboembolic events group than those in non-thromboembolic events group. There was no significant difference in vWF between the two group (126.97±63.96 vs 103.79±53.61%, P>0.05).(7) The amplitude of fibrillatory wave showed a significant negative correlation with the age (r=-0.41, P<0.05); and a positive correlation with the f-f interval (r=0.28, P<0.05).(8) Multiple logistic regression analysis revealed that the amplitude of fibrillatory wave was an independent clinical risk factor of thromboembolic events.Conclusions (1) The incidence rate of thromboembolic events in fine AF is higher than in coarse AF; vWF, as an indices of endothelial damage, is higher in fine AF. It shows that fine AF was correlated with the risk of thromboembolism.(2) The amplitude of fibrillatory wave shows a negative correlation with the age; and a positive correlation with the f-f interval. The amplitude of fibrillatory wave is significantly smaller in NVAF patients with thromboembolic events than that in patients without thromboembolic events; and f-f interval is shorter than the latter. So the amplitude of fibrillatory could conduce to predict the risk of thromboembolism.(3) The plasma GMP-140,D-dimer and AT-Ⅲare higher in patients with thromboembolic events than those without thromboembolic events. This group of blood makers has some significance in estimating the risk of thromboembolism.(4) The amplitude of fibrillatory wave of surface ECG is an independent clinical risk factor of thromboembolic events in patients with NVAF. |
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