Comparison of the incidence of protrusive atheromatous plaques of the thoracic aorta in patients in atrial flutter and in atrial fibrillation

Although it has been demonstrated recently that in patients with atrial fib rillation, protrusive atheromatous plaques of the thoracic aorta (thickness 4 mm) and left atrial abnormalities such as thrombosis, spontaneous contra st and low atrial blood flow velocities carry an additional embolic risk, t his has not yet been studied in atrial flutter. Out of 2493 patients undergoing transoesophageal echocardiography between S eptember 1993 and December 1997, 271 consecutive patients in atrial flutter (N = 41) or fibrillation (N = 230) far over 48 hours, underwent transoesop hageal echocardiography before cardioversion. Patients with atrial flutter were compared with those with atrial fibrillation. Their characteristics we re comparable with respect to age (68 +/- 13 and 67 +/- 12 yeats respective ly, 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 o f protrusive aortic atheroma (12 and 11% respectively, p = 0.919), of spont aneous 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 cm(2) respectively, p = 0.001), spontaneous atrial c ontrast less frequent (17 and 37% respectively, p = 0.024) and the velociti es 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 dis ease (S 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 cm(2), p = 0.38 4) or in intraatrial thrombosis (2 and 3%, p = 0.888) respectively. These results show a high prevalence of protrusive atheroma of the thoracic aorta bath in atrial nutter and in atrial fibrillation, and fewer left atr ial abnormalities in patients with flutter.