[Comparative incidence of protrusive atheromatous plaques of the thoracic artery in patients with atrial fluter and atrial fibrillation]. / Fréquence comparée des plaques athéromateuses protrusives de l'aorte thoracique chez les patients en flutter et en fibrillation auriculaire.

Although it has been demonstrated recently that in patients with atrial fibrillation, protrusive atheromatous plaques of the thoracic aorta (thickness 4 mm) and left atrial abnormalities such as thrombosis, spontaneous contrast and low atrial blood flow velocities carry an additional embolic risk, this has not yet been studied in atrial flutter. Out of 2493 patients undergoing transoesophageal echocardiography between September 1993 and December 1997, 271 consecutive patients in atrial flutter (N = 41) or fibrillation (N = 230) for over 48 hours, underwent transoesophageal echocardiography before cardioversion. Patients with atrial flutter were compared with those with atrial fibrillation. Their characteristics were comparable with respect to age (68 +/- 13 and 67 +/- 12 years respectively, p = 0.628), sex ratio (men 66 and 54% respectively, p = 0.212), previous thromboembolic disease (5 and 15% respectively, p = 0.126). The incidence of protrusive aortic atheroma (12 and 11% respectively, p = 0.919), of spontaneous contrast in the thoracic aorta (15 and 14% respectively, p = 0.847) were identical in both groups. The left atrium was significantly smaller (3.1 +/- 0.7 and 6 +/- 3 cm2 respectively, p = 0.001), spontaneous atrial contrast less frequent (17 and 37% respectively, p = 0.024) and the velocities of atrial emptying higher (47 +/- 10 and 30 +/- 10 cm/s respectively, p = 0.030) in patients with flutter compared with atrial fibrillation. There was no difference in left ventricular fractional shortening (30 +/- 10 and 33 +/- 13% respectively, p = 0.630), the presence of rheumatic valvular disease (5 and 12%, p = 0.301), left atrial diameter (43 +/- 7 and 45 +/- 8, p = 0.134), right atrial surface area (16 +/- 4 and 17 +/- 6 cm2, p = 0.384) or in intraatrial thrombosis (2 and 3%, p = 0.888) respectively. These results show a high prevalence of protrusive atheroma of the thoracic aorta both in atrial flutter and in atrial fibrillation, and fewer left atrial abnormalities in patients with flutter.