Left atrial appendage outflow velocity index is superior to conventional criteria for prediction of maintenance of sinus rhythm after cardioversion. An echocardiographic study in patients with atrial fibrillation of a few months' duration.

OBJECTIVE

To investigate whether left atrial appendage outflow velocity alone or in relation to left atrial diameter is a superior predictor of sinus rhythm maintenance after cardioversion compared with traditional clinical or echocardiography parameters.

DESIGN

Sixty-two patients with their first episode of atrial fibrillation were examined using echocardiography before DC-cardioversion. At one month's follow-up, 42 patients had maintained sinus rhythm (group A), and 20 had relapsed into atrial fibrillation (group B). There were no differences in arrhythmia duration or antiarrhythmic therapy between the groups.

RESULTS

Left atrial diameter measured by echocardiography was smaller in group A (42 mm, 95% CI 40.9-44.1 mm) compared with group B (46 mm, 95% CI 43.4-48.2, p < 0.05). Patients in group A had a higher left atrial appendage outflow velocity at 0.44 m/s (95% CI 0.39-0.49) compared with 0.34 m/s (95% CI 0.30-0.37) in group B (p < 0.01). The ratio of left atrial appendage flow to left atrial diameter was 0.011 (95% CI 0.009-0.012) in group A compared with 0.008 (95% CI 0.007-0.009) in group B, and 63% (95% CI 33-78) of the patients in group A had velocity ratio >0.009 compared with 20% (95% CI 2-38) in group B, (p < 0.01). Stepwise multiple logistic regression analysis showed that a velocity ratio >0.009 was the only predictor for maintenance of sinus rhythm one month after cardioversion with an odds ratio of 6.4 (95% CI 1.9-23.8), (p = 0.004).

CONCLUSION

The ratio of left atrial appendage outflow velocity to left atrial diameter is superior to the traditionally used criteria for prediction of maintenance of sinus rhythm following DC-conversion of first-episode atrial fibrillation.