Andreas Brandt

Embolic events in patients with atrial fibrillation and effective anticoagulation: value of transesophageal echocardiography to guide direct-current cardioversion: Final results of the Ludwigshafen Observational Cardioversion Study

OBJECTIVES The primary objective was to evaluate the usefulness of transesophageal echocardiography (TEE)-guided cardioversion to prevent thromboembolic complications in patients with atrial fibrillation (AF) and effective anticoagulation (International Normalized Ratio of 2 or 3) at least three weeks before cardioversion. BACKGROUND Transesophageal echocardiography has been proposed as a method of screening patients for left atrial thrombi before direct-current cardioversion of AF. The usefulness of TEE as a screening tool has always been evaluated in patients without long-term anticoagulation before cardioversion. METHODS This prospective, single-center, observational study, performed on an intention-to-cardiovert basis, comprised 1,076 consecutive, unselected patients with AF. The initial two years were designed to be the control phase, during which the conventional approach was used. After that, cardioversion guided by TEE was performed in consecutive patients. RESULTS The prevalence of left atrial thrombi was 7.7% in patients with persistent AF and effective anticoagulation. During the first four weeks after electrical cardioversion, six thromboembolic complications were observed in patients in whom the TEE-guided approach was employed (6 [0.8%] of 719 patients), compared with three thromboembolic complications in patients in whom the conventional approach was used (3 [0.8%] of 357 patients). None of the patients in whom electrical cardioversion was not performed experienced an embolic event. CONCLUSIONS There were no differences in the rate of embolic events between the two treatment groups. In patients with AF and effective anticoagulation, TEE-guided electrical cardioversion does not reduce the embolic risk. However, TEE revealed left atrial thrombi in 7.7% of patients with AF and effective anticoagulation, before direct-current cardioversion.

Acute and long-term thromboembolic events in patients with atrial tachyarrhythmias: Comparison between atrial fibrillation, atrial flutter plus atrial fibrillation, and pure atrial flutter

Recent studies showed controversial results on the prevalence of atrial thrombi and the risk of thromboembolism (TE) after restoring sinus rhyihm in patients (pts) with atrial flutter (AFlut). Primary objective of this prospective observation1 study, performed on an intention to cardiovert basis, was to evaluate the thromboembolic event rate (TE) in pts with pure AFlut compared to pts with atrial fibrillation (AF). This study comprised 1639 pts (1269 pts with atrial fibrillation (AF), 206 pts with AFlut and AF, 362 pts with pure AFlut). Results: Transesophageal echocardiography was performed in 645 pts with AF and in 209 pts with pure AFIut. Left atrial thrombi were detected in 65/845 pts with AF (7,7 %) compared to 61209 pts with Aflutt (3,8 %). Spontaneous echo contrast was observed in 4291845 pts (51%) with AF compared to 43/209 pts (21%) with AFIut. Effective anticoagulation (INR 2-3) was obtained in 65% of pts with AF compared to 63% of pts with AF plus AFlut and 57% of pts with pure AFlut. Acute and longterm TE are listed in the table. Conclusiorxl) Transesophageal echo revealed 2 times more often left atrial thrombi in pts with pure AF compared to pure AFlut. 2) Pts with AF had 3 times more often a history of TE compared to pts with AFIut. 3) The thromboembolic event rate in between 4 weeks after cardioversion was not different between pts with AF compared to pts with AFlut. 4) During a long-term follow up thromboembolic events occurred 2 times more often in pts with AF plus AFlut. compared to pts with pure AF or pure AFlut.

Catheter ablation of chronic atrial fibrillation guided by noncontact mapping: are continuous linear lesions associated with ablation success?

Catheter-based, right and left atrial compartmentalization procedure was evaluated using a noncontact mapping (NCM) system. Its usefulness to identify and close discontinuities in linear lesions in both atria was evaluated. The impact of linear lesion continuity on ablation success of chronic AF was also investigated. Nineteen patients with symptomatic, drug refractory chronic AF were studied. Right atrial ablation with three predefined lines was attempted in all patients. In 18 patients, left atrial ablation was performed with four linear lesions. During a follow-up of 12 +/- 3 months, 6 of 19 patients remained in sinus rhythm (SR) without antiarrhythmic agents (AAs). In addition, four patients were maintained in SR with AA. Thirteen of 14 patients with gaps identified during off-line analysis had recurrence of AF. Only one patient with a gap was free of recurrence without AAs. In the remaining five patients without recurrence of AF, no gap was observed during off-line analysis. In all four patients who were free of AF with additional treatment of AAs, two gaps had been identified. In the remaining nine patients with chronic AF recurrence, a mean of 4.9 gaps were identified. Excluding the initial learning period (first five patients) the success rate increased to 43% (6/14 patients) without and to 71% (10/14 patients) with AA. NCM identifies discontinuities in lines of ablation. Successful ablation of chronic AF is associated with continuity of linear lesions and good clinical technique demands a vigilant search for and closure of every gap.