Digitalis does not improve left atrial mechanical dysfunction after successful electrical cardioversion of chronic atrial fibrillation.

This study was designed to investigate whether administration of digitalis could improve mechanical function of left atrial appendage (LAA) and left atrium prospectively in patients with atrial stunning. Fifty-four consecutive patients in whom atrial stunning was observed immediately after cardioversion of chronic atrial fibrillation (AF) were randomized into digitalis or control group for 1 week following cardioversion. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were performed prior to, immediately following, 1 day after and 1 week after cardioversion to measure transmitral flow velocity and LAA flow velocity. Electrical cardioversion of AF elicited significantly slower left atrial appendage peak emptying velocity (LAA-PEV) and peak filling velocity (LAA-PFV) immediately following cardioversion in both groups. 1 day post cardioversion, there were no significant differences in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or left atrial appendage ejection fraction (LAA-EF) between digitalis and control groups. 1 week post cardioversion, no significant differences were found in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or LAA-EF between the two groups. The occurrence rates of spontaneous echo contrast were not significantly different between digitalis and control groups one day and one week post cardioversion. In conclusion, digitalis did not improve left atrial and appendage mechanical dysfunction following cardioversion of chronic AF. Digitalis did not prevent the development of spontaneous echo contrast in left atrial chamber and appendage. This may be due to the fact that digitalis aggravates intracellular calcium overload induced by chronic AF and has a negative effect on ventricular rate.

Predictors of left atrial appendage stunning after electrical cardioversion of non-valvular atrial fibrillation / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To identify predictors of left atrial appendage stunning after the use of electrical cardioversion to restore sinus rhythm in patients with non-valvular atrial fibrillation.</p><p><b>METHODS</b>A total of 68 consecutive patients (45 men, 23 women, 60.5 +/- 8.7 years of age) with non-valvular atrial fibrillation undergoing electrical cardioversion were enlisted in this study. Clinical and echocardiographic variables were analyzed by univariate regression and multivariate logistic regression to investigate the relationship between occurrences of left atrial appendage stunning and these factors.</p><p><b>RESULTS</b>Univariate analysis revealed that, in comparing patients without and with left atrial appendage stunning, there were significant differences in the duration of atrial fibrillation > 8 weeks (32.3% vs 75.5%, P < 0.001), left atrial diameter > 50 mm (29.0% vs 54.1%, P < 0.05), left atrial emptying fraction (31.5% +/- 7.8% vs 27.1% +/- 8.5%, P < 0.05), left ventricular ejection fraction < 50% (38.7% vs 67.6%, P < 0.05), maximum electrical energy (96.8 J +/- 65.8 J vs 156.8 J +/- 100.8 J, P < 0.01), cumulative electrical energy 146.8 J +/- 142.6 J vs 290.5 J +/- 242.1 J, P < 0.01) and number of electrical cardioversion shocks (1.7 +/- 0.9 vs 2.43 +/- 1.20, P < 0.05). However, backward stepwise multivariate logistic regression analysis identified as significant and independent predictors of left atrial appendage stunning only duration of atrial fibrillation > 8 weeks (OR = 7.249, 95% CI = 1.998 - 26.304, P < 0.01), left atrial diameter > 50 mm (OR = 3.896, 95% CI = 1.105 - 13.734, P < 0.05), left ventricular ejection fraction < 50% (OR = 4.465, 95% CI = 1.51713.140, P < 0.01) and cumulative energy of electrical cardioversion (OR = 1.004, 95% CI = 1.000 - 1.008, P < 0.05).</p><p><b>CONCLUSIONS</b>Duration of atrial fibrillation > 8 weeks, left atrial diameter > 50 mm, left ventricular ejection fraction < 50%, and cumulative energy of electrical cardioversion are independent predictors of left atrial appendage stunning. Anticoagulation treatment should be individualized for patients undergoing electrical cardioversion to reduce the risk of both cardioversion-related thromboembolic events and hemorrhagic complications caused by warfarin treatment.</p>