Atrial Mechanical Function Before and After Electrical or Amiodarone Cardioversion in Atrial Fibrillation: Assessment by Transesophageal Echocardiography and Pulsed Doppler

In some patients with atrial fibrillation (AF), it has been suggested that left atrial mechanical dysfunction can develop after successful electrical cardioversion, justifying postcardioversion anticoagulant treatment. The purpose of this study was to investigate differences in left atrial appendage peak flow velocities and the incidence of left atrial spontaneous echo contrast in patients with AF before and after electrical cardioversion or intravenous amiodarone, studied using transesophageal echocardiography (TEE) and pulsed Doppler. We performed a control TEE in 7 patients in the electrical group and 6 in the amiodarone group, with no significant clinical differences between both groups. A second TEE was performed immediately in the 7 patients with successful electrical cardioversion. The peak flow velocities in the appendage before and after the procedure were: filling 43.3 ± 22 vs 27.7 ± 28 cm/sec (P = 0.01) and emptying 35.5 ± 22 vs 23.6 ± 17 cm/sec (P = 0.01), respectively. The spontaneous echo contrast increased in 4 of the 7 patients. In 4 patients of the amiodarone group, the peak flow velocities in the appendage during AF and within the first 24 hours after restoration of sinus rhythm were: filling 37.4 ± 12 vs 37.8 ± 18 cm/sec and emptying 36.4 ± 18 vs 35.9 ± 18 cm/sec, respectively (P = NS). There was no change in spontaneous echo contrast. In conclusion, patients with AF reverted to sinus rhythm using amiodarone did not show changes in left atrial mechanical function; however, patients with electrical cardioversion showed mechanical dysfunction. Further investigations on the effects of amiodarone and other drugs on the mechanical function of the atria are needed to determine if patients reverted pharmacologically require antico-agulation post reversion.