Comparison of echocardiographic markers of embolism in atrial flutter and fibrillation: frequency of protruding atherosclerotic plaques in the thoracic aorta.

Abstract

The potential additional embolic risk of protruding aortic plaques > or = 4 mm and left atrial abnormalities such as thrombus, spontaneous echocardiographic contrast (SEC), low left atrial appendage velocity, recently has been shown in patients with atrial fibrillation (AF). However, the presence and potential role of transesophageal echocardiographic (TEE)-detected protruding aortic plaques > or = 4 mm have not been systematically evaluated in patients with atrial flutter. Among 2493 patients evaluated by TEE, 271 consecutive patients with atrial flutter (n = 41) and AF (n = 230) > or = 2 days duration were included in the study. Clinical and echocardiographic characteristics in consecutive patients with atrial flutter were compared to those in patients with AF, especially atrial morphology and function and atherosclerotic disease of the thoracic aorta. Clinical characteristics of patients with atrial flutter and AF were similar with regard to age (68 +/- 13 and 67 +/- 12, P = 0.628), sex ratio (men, 66% and 54%, P = 0.212), and previous embolic events (5% and 15%, P = 0.126), respectively. The frequency of protruding atherosclerotic plaques > or = 4 mm (12% and 11%, P = 0.919) and SEC (15% and 14%, P = 0.847) in the thoracic aorta was similar in patients with atrial flutter and AF. Left atrial appendage area was smaller (3.1 +/- 0.7 and 6.0 +/- 3.0 cm(2), P = 0.001), left atrial appendage SEC was less frequent (17% and 37%, P = 0.024), and left atrial appendage emptying velocity was higher (47 +/- 10 and 30 +/- 10 cm/s, P = 0.030) in patients with atrial flutter as compared to those with AF. There was no difference between the two groups regarding left ventricular fractional shortening (30 +/- 10% and 33 +/- 13%, P = 0.630), rheumatic valvular disease (5% and 12%, P = 0. 301), left atrial diameter (43 +/- 7 and 45 +/- 8 mm, P = 0.134), right atrial area (16 +/- 4 and 17 +/- 6 cm(2), P = 0.384), left atrial SEC (39% and 53%, P = 0.124), or atrial thrombus ( 2% and 3%, P = 0.888) respectively. Our results point to the high prevalence of protruding atherosclerotic plaques in the thoracic aorta in patients with atrial flutter.