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Background: In patients treated for paroxysmal atrial fibrillation, the pulmonary vein (PV) reconnection rate is substantial and may be related to the lack of transmurality achievement while performing PV isolation (PVI). It has been experimentally demonstrated that positive unipolar atrial electrogram completion, when applying radiofrequency energy, was associated with transmural lesions. In this regard, we seek to determine whether the unipolar signal modification may be an appropriate end point for point-by-point radiofrequency application and find out whether it could improve the paroxysmal atrial fibrillation ablation results in humans., Methods and Results: Fifty consecutive patients (61±8 years old, 41 men) with paroxysmal atrial fibrillation underwent PVI using Carto and Lasso. Each radiofrequency application lasted until development of a completely positive unipolar electrogram. Fifty patients (63±9 years old, 40 men), who previously underwent PVI following the standard approach of our institution, corresponded to the control group. All PVs were isolated in all patients of both groups. However, the procedural and ablation times were significantly lower in the unipolar group compared with those of the control group, whereas the PV reconnection rate, after 30 minutes of waiting time, was not significantly different. Overall, 21±4 months after 1 PVI session, the sinus rhythm maintenance rate without antiarrhythmic drugs was significantly higher (P=0.027) in the unipolar group (88%) compared with that of the control group (70%)., Conclusions: Unipolar signal modification is a useful end point for radiofrequency energy delivery in patients with paroxysmal atrial fibrillation who undergo PVI and leads to a substantial midterm sinus rhythm maintenance rate.

Aims: In congestive heart failure (CHF) patients with persistent atrial fibrillation (AF), direct current cardioversion (DCC) may reveal participation of tachycardiamediated process to left ventricular (LV) dysfunction by restoring sinus rhythm (SR). However, if DCC fails to restore SR, patients' management remains challenging. The aim of the study was to assess the AF catheter ablation benefit in a selected group of CHF patients with LV ejection fraction (LVEF) <40% and persistent AF unresponsive to DCC, in whom a tachycardia-mediated process is thought to be predominant., Methods and Results: Between January 2008 and September 2011, among 129 CHF patients with persistent AF referred to our institution, 34 (63.8 ± 9-year old, 24 men) presented AF refractory to DCC with an estimated high likelihood of tachycardia-mediated LV dysfunction according to a specific set of criteria. These 34 patients underwent stepwise AF ablation and were closely followed up. After a mean 1.9 AF ablation procedures per patient and 17.6 ± 7 months after the last procedure, all patients were in SR. The New York Heart Association class improved from 2.8 ± 0.3 to 1 ± 0.2 (P< 0.001) and the LVEF increased from 30.4 ± 6 to 54.6 ± 6% (P< 0.0001) after 3-6 months of SR, with a persistent benefit as long as the SR was maintained., Conclusion: Atrial fibrillation catheter ablation in selected CHF patients with persistent AF refractory to DCC and without any other evidence for secondary LV dysfunction leads to a substantial LVEF improvement in the majority of them. However, redo procedures are frequent in order to achieve mid-term SR maintenance.

Unipolar Signal and Atrial Flutter Ablation Introduction Complete elimination of the negative component of the unipolar atrial electrogram recently proved predictive of lesions transmurality. We prospectively assessed its relevance as a real-time local ablative endpoint for each individual lesion created across the cavotricuspid isthmus (CTI) in order to constitute a line of bidirectionnal block during common atrial flutter (AFL) ablation. Methods and Results Sixty-two consecutive patients underwent common AFL ablation following an electrophysiological approach guided by real-time electrogram modification analysis. In 31 patients (unipolar group), the local ablative endpoint was complete elimination of the negative component of the unipolar atrial electrogram, while the other 31 patients (control group) were treated following our standard approach based on the currently used local ablative endpoint defined by a ≥50% amplitude decrease of the bipolar atrial electrogram. Bidirectional block was achieved in all patients (mean age 67.9 ± 11.5 with 80.6% of men). Mean ablation time (164.3 ± 88.3 seconds vs 332.8 ± 151.5 seconds; P < 0.001) and mean energy delivery (7.5 ± 4.1 kJ vs 14.2 ± 6 kJ; P < 0.001) were significantly shorter in the unipolar group compared to the control group. No statistical differences were seen in procedure time (68.5 ± 22.6 min vs 77.5 ± 20.2 min; P = 0.10). Conclusion Real-time unipolar electrogram modification is a relevant local endpoint during common AFL ablation and leads to a substantial reduction of ablation time and energy delivery compared to a standard ablative approach while displaying a similar short- and long-term success rate. [ABSTRACT FROM AUTHOR]

Aims In congestive heart failure (CHF) patients with persistent atrial fibrillation (AF), direct current cardioversion (DCC) may reveal participation of tachycardiamediated process to left ventricular (LV) dysfunction by restoring sinus rhythm (SR). However, if DCC fails to restore SR, patients' management remains challenging. Methods and results Between January 2008 and September 2011, among 129 CHF patients with persistent AF referred to our institution, 34 (63.8 ± 9-year old, 24 men) presented AF refractory to DCC with an estimated high likelihood of tachycardia-mediated LV dysfunction according to a specific set of criteria. These 34 patients underwent stepwise AF ablation and were closely followed up. After a mean 1.9 AF ablation procedures per patient and 17.6 ± 7 months after the last procedure, all patients were in SR. The New York Heart Association class improved from 2.8 ± 0.3 to 1 ± 0.2 (P< 0.001) and the LVEF increased from 30.4 ± 6 to 54.6 ± 6% (P< 0.0001) after 3–6 months of SR, with a persistent benefit as long as the SR was maintained. Conclusion Atrial fibrillation catheter ablation in selected CHF patients with persistent AF refractory to DCC and without any other evidence for secondary LV dysfunction leads to a substantial LVEF improvement in the majority of them. However, redo procedures are frequent in order to achieve mid-term SR maintenance. [ABSTRACT FROM PUBLISHER]