Role of transthoracic left atrial appendage wall motion velocity in patients with persistent atrial fibrillation and a low CHADS2 score

Background and purposeThromboembolic risk has been examined by semi-invasive transesophageal echocardiography. We assessed the risk of thrombogenesis in patients with persistent atrial fibrillation (AF) noninvasively by using transthoracic tissue Doppler echocardiography (TDE) in relation to a low CHADS2 score.MethodsEighty patients with persistent AF underwent both transthoracic and transesophageal echocardiography. Peak left atrial appendage (LAA), wall motion velocity (WV) during LAA contraction was measured by transthoracic and transesophageal TDE. LAA flow velocity was also determined by transesophageal echocardiography.ResultsTransthoracic LAAWV could be measured in 78 of the 80 patients, and the values were closely correlated with transesophageal TDE values (r = 0.98) and with transesophageal LAA flow velocity (r = 0.82). Transthoracic LAAWV was significantly lower with increasing spontaneous echo contrast (SEC) severity (severe SEC, mild SEC, no SEC: 5.7 ± 2.4, 10.2 ± 3.3, and 14.5 ± 5.5 cm/s, respectively). Severe SEC was noted in 31 of 61 patients with a CHADS2 score ≤2, in 19 of 46 patients with a CHADS2 score ≤1 and in 6 of 21 patients with a CHADS2 score = 0. For diagnosing severe SEC, a transthoracic LAAWV <10 cm/s had a sensitivity of 81% and specificity of 92% in the patients with a CHADS2 score ≤2, a sensitivity of 74% and specificity of 91% in the patients with a CHADS2 score ≤1 and a sensitivity of 44% and specificity of 83% in the patients with a CHADS2 score = 0.ConclusionsA transthoracic LAAWV <10 cm/s in persistent AF patients with a low CHADS2 score may be a very specific diagnostic tool for evaluating severe SEC, one of the high risk factors for thromboembolism.