Left atrial diverticula in patients undergoing atrial fibrillation ablation: morphologic analysis and clinical impact.

Left atrial diverticula (LAD) have been reported to be (1) at risk for intracavitary thrombosis and cardiac perforation during ablation and (2) sites of extrapulmonary vein foci. In atrial fibrillation (AF) ablation, their presence might undermine procedure safety and efficacy. This observational study evaluates the morphology and clinical impact of LAD in patients undergoing AF ablation. Consecutive patients undergoing computed tomography scan (Aquilion 64, Toshiba, Otawara, Japan) and AF ablation with imaging integration (CARTO 3 Merge, Biosense Webster, CA, USA) in our center were included. Morphologic analysis was performed by 2 independent radiologists. Ablation was obtained by irrigated radiofrequency energy (Navistar Thermocool or Thermocool SF, Biosense Webster). Out of 212 patients, 58 (27.3%) had LAD; 74.4% of LAD were located in the anterosuperomedial left atrium. In patients with and without LAD, the prevalence of prior cerebrovascular events was similarly low. The rate of major periprocedure complications did not differ significantly: 1.7% versus 2.6% (P = 1) in patients with and without LAD, respectively. However, 1 case of cardiac perforation occurred during ablation in a diverticulum. During follow-up, survival free from arrhythmia recurrences was comparable in the 2 groups. LAD are present in about one-fourth of patients undergoing AF ablation and, in general, they have no impact on its safety and efficacy. However, occasionally, radiofrequency energy delivery in a LAD can cause tissue overheating and perforation.

De Ponti R ，Lumia D ，Marazzi R ，Mameli S ，Doni LA ，De Venuto G ，Fugazzola C ，Salerno-Uriarte JA ... -  《-》

Efficacy of catheter ablation in nonparoxysmal atrial fibrillation patients with severe enlarged left atrium and its impact on left atrial structural remodeling.

The effect of catheter ablation on severe left atrial enlargement especially in nonparoxysmal atrial fibrillation (NPAF) patients is not well understood. Whether reverse remodelling may occur after ablation has not been evaluated in this setting. Fifty consecutive patients with left atrial diameter (LAD) ≥50 mm, and LA volume >200 cc undergoing catheter ablation for drug-refractory NPAF were included in this study. Transthoracic echocardiographic measurements were performed at baseline and at 12-months postprocedure. Left ventricular end-diastolic and end-systolic dimensions were indexed by body surface area (LVEDDI, LVESDI). Electroanatomic mapping system (Carto or NavX system) and computed tomography (CT) were used for 3-dimensional reconstruction of the LA. All patients underwent posterior wall isolation and pulmonary vein (PV) antrum and extra PV trigger ablations. Long-term follow-up was monitored by event recordings, 7-day Holter monitors and office visits. The mean age was 65 ± 10 years, 78% male, persistent AF 22 (44%), longstanding AF 28 (56%), LAD diameter 56.9 ± 7.8 mm, left ventricular ejection fraction (LVEF) 53 ± 14 and median AF duration 72 (49-96) months. At 12-month follow-up, 27 patients (54%) remained arrhythmia-free off antiarrhythmic drugs. Significant reduction in LAD at follow-up (≥10% reduction) was observed in 52% (26/50) of the total population and among the 63% (17/27) of recurrence-free patients. Magnitude of LA reduction was identically distributed among the persistent and longstanding persistent AF cohorts (16 ± 12% vs 14 ± 16%, respectively, P = 0.15). A significant 20% improvement in LVEF (from 53 ± 14 to 58 ± 9, P = 0.03) was found in the overall population. Improvement was noted in recurrence-free patients. No significant change in LVEDDI and LVESDI was noted. After adjusting for baseline risk factors in a multivariable model, a reduction in LAD was identified as a strong predictor of long-term success (beta = -11.1, P = 0.013). Preexisting LA scarring was associated with increased LAD (beta = 2.7, P = 0.023). No periprocedural or long-term complications were reported. Our results show that atrial fibrillation ablation is effective in NPAF patients with severe LA enlargement and is associated with LA reverse remodeling and improvement in LVEF.

Pump A ，Di Biase L ，Price J ，Mohanty P ，Bai R ，Santangeli P ，Mohanty S ，Trivedi C ，Yan RX ，Horton R ，Sanchez JE ，Zagrodzky J ，Bailey S ，Gallinghouse GJ ，Burkhardt JD ，Natale A ... -  《-》

Left atrial diverticula in patients referred for radiofrequency ablation of atrial fibrillation: assessment of prevalence and morphologic characteristics by dual-source computed tomography.

Peng LQ ，Yu JQ ，Yang ZG ，Wu D ，Xu JJ ，Chu ZG ，Li XM ，Chen DD ，Luo Y ，Shao H ，Tang SS ，Chen J ... -  《-》

Potential arrhythmic substrate of atrial fibrillation at the left atrial diverticulum.

Takayanagi T 《Nagoya Journal of Medical Science》

Left atrial volumetry from routine diagnostic work up prior to pulmonary vein ablation is a good predictor of freedom from atrial fibrillation.

Sohns C ，Sohns JM ，Vollmann D ，Lüthje L ，Bergau L ，Dorenkamp M ，Zwaka PA ，Hasenfuß G ，Lotz J ，Zabel M ... -  《-》