CLINICAL-SIGNIFICANCE OF FIBRILLATORY WAVE AMPLITUDE - A CLUE TO LEFTATRIAL APPENDAGE FUNCTION IN NONRHEUMATIC ATRIAL-FIBRILLATION

Seventy-eight patients with chronic nonrheumatic atrial fibrillation w ere studied by transesophageal echocardiography with regard to the lef t atrial appendage function and its relation to the coarseness of atri al fibrillation on electrocardiogram. These 78 patients (52 men and 26 women; mean age, 66+/-10 years; range, 40 to 94 years) were classifie d into two groups according to the presence of coarse (group 1, n=46; those with the greatest amplitude of fibrillatory wave in lead V-1 gre ater than or equal to 1 mm) or fine (group 2, n=32; those without the coarse fibrillatory wave in lead V-1) atrial fibrillation on a standar d le-lead electrocardiogram within 1 month of echocardiographic studie s, There were no significant differences in age, sex, mean duration of atrial fibrillation, left ventricular end-diastolic dimension, left v entricular end-systolic dimension, left ventricular ejection fraction, and left atrial dimension between the two groups, In group 1, however , the left atrial appendage ejection fraction (24.4+/-14.2% vs 32.6+/- 14.8%; p<0.05) and the peak emptying velocity (21.7+/-12.6 cm/s vs 30. 4+/-14.3 cm/s; p<0.01) were lower than those in group 2, There were hi gher incidences of left atrial appendage spontaneous echo contrast (26 /46 vs 7/32; p<0.005) and thrombus (8/46 vs 0/32; p<0.05) in group 1 p atients, The coarse atrial fibrillation revealed a sensitivity of 80.0 %, a specificity of 58.1%, a positive predictive value of 60.9%, and a negative predictive value of 78.1% for the presence of left atrial ap pendage spontaneous echo contrast and/or thrombus formation, In conclu sion, in patients with coarse nonrheumatic atrial fibrillation, the le ft atrial appendage function is usually poor and the incidence of spon taneous echo contrast and thrombus formation appears to be higher in t hese patients.