QUANTIFICATION OF BLOOD ECHOGENICITY - EVALUATION OF A SEMIQUANTITATIVE METHOD OF GRADING SPONTANEOUS ECHO CONTRAST

Spontaneous echo contrast (SEC) is an echogenic, swirling pattern of b lood flow which may be observed by transesophageal echocardiography (T EE) in the left atrium in low flow states, such as atrial fibrillation (AF). The presence of SEC has been proposed as a marker of increased thromboembolic risk. Evaluation of the severity of SEC might be useful in stratification of thromboembolic risk. The aim of this study was t o validate a semiquantitative method of grading SEC against quantitati ve videodensitometric analysis. TEE studies were performed in 50 patie nts with AF. The severity of left atrial SEC was graded by three indep endent observers and by videodensitometry. There was a strong, positiv e correlation between the semiquantitative grades of SEC and quantitat ive videodensitometric scores (r = 0.85, P < 0.0001). Inter- and intra observer correlations in the grading of SEC were very high (observer 1 vs. 2: r = 0.98, P = 0.0001; observer 1 vs. 3: r = 0.93, P = 0.0001; observer 1 vs. 1: r = 0.97, P = 0.0001). Semiquantitative grading of S EC can be performed rapidly and reliably by experienced observers. The se results support the use of semiquantitative grading in studies of t he pathogenesis and prognostic implications of SEC.