Introduction: Left atrial (LA) roof ablation using the cryoballoon technique, combined with pulmonary vein isolation (PVI), has been reported to be beneficial for ablation therapy in patients with persistent atrial fibrillation (AF). Left posterior wall ablation also results in improved patient outcomes. However, the contribution of these techniques to the success of cryoballoon ablation (CBA) treatment of AF is not known. The present study examined the influence of the roofline block and isolation area on outcomes after CBA. Methods and Results:We enrolled 78 patients with persistent AF. LA roof ablation was performed using a 28-mm cryoballoon with a single freezing of 3 minutes at each region (median number of freezes: 4) after PVI. After CBA, bipolar voltage amplitude mapping was performed during sinus rhythm using the NavX mapping system.Patients were divided into two subgroups according to the voltage and activation map: the roof-conduction (n = 46) and roofline-block groups (n = 32). Atrial tachyarrhythmia recurred in 20 patients of the conduction group and 4 patients of the roofline-block group. The rate of 12-month freedom from tachyarrhythmia after a single ablation procedure was 78% (95% confidence interval [CI], 60%-89%) in the roofline-block group and 45% (95% CI, 30%-60%) in the conduction group (P = .048).Cox proportional hazard analysis revealed that the isolated area was not a significant predictor of recurrence (hazard ratio, 0.94; 95% CI, 0.86-1.02; P = .15). Conclusion:Creating a complete roofline block is the major factor predicting the maintenance of sinus rhythm in patients with persistent AF. K E Y W O R D S ablation, atrial fibrillation, pulmonary vein, roofline block, sinus rhythm

Extensive isolation is superior to individual isolation for achieving freedom from atrial arrhythmia in long term follow-up by CBA. Evaluating PV diameter at the left atrial PV junction is essential for applying CBA.

Background: Esophageal thermal injury (ETI) is a known and potentially serious complication of catheter ablation for atrial fibrillation. We intended to evaluate the distance between the esophagus and the left atrium posterior wall (LAPW) and its association with esophageal thermal injury.Methods: A retrospective analysis of 73 patients who underwent esophagogastroduodenoscopy (EGD) after LA radiofrequency catheter ablation for symptomatic atrial fibrillation and pre-ablation magnetic resonance imaging (MRI) was used to identify the minimum distance between the inner lumen of the esophagus and the ablated atrial endocardium (pre-ablation atrial esophageal distance; pre-AED) and occurrence of ETI. Parameters of ablation index (AI, Visitag Surpoint) were collected in 30 patients from the CARTO3 system and compared with assess if ablation strategies and AI further impacted risk of ETI.Results: Pre-AED was significantly larger in patients without ETI than those with ETI (5.23 ± 0.96 mm vs. 4.31 ± 0.75 mm, p < .001). Pre-AED showed high accuracy for predicting ETI with the best cutoff value of 4.37 mm. AI was statistically comparable between Visitag lesion markers with and without associated esophageal late gadolinium enhancement (LGE) detected by postablation MRI in the low-power

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BACKGROUND: Pre-clinical large animal models of chronic heart failure (HF) are crucial to both understanding pathological remodeling and translating fundamental discoveries into novel therapeutics for HF. Canine models of ischemic cardiomyopathy are historically limited by either high early mortality or failure to develop chronic heart failure. METHODS: Twenty-nine healthy adult dogs (30±4 kg, 15/29 male) underwent thoracotomy followed by one of three types of left anterior descending (LAD) coronary artery ligation procedures: Group 1 (n=4) (Simple LAD: proximal and distal LAD ligation); Group 2 (n=14), (Simple LAD plus Lateral ligation of the distal first diagonal and proximal first obtuse marginal); and Group 3 (n=11), (Total LAD Devascularization or TLD: Simple LAD plus ligation of proximal LAD branches to both the right and left ventricles). Dogs were followed until chronic severe HF developed defined as left ventricular ejection fraction (LVEF) <40% and N-terminal prohormone B-type Natriuretic peptide (NT-proBNP) >900 pmol/L. RESULTS: Overall early survival (48-hour post ligation) in 29 dogs was 83% and survival rate at post-ligation 5 weeks was 69%. Group 1 and Group 2 had 100% and 71% early survival, respectively, yet only a 50% success rate of developing chronic HF. Group 3 had excellent survival at post-ligation 48 hour (91%) and a 100% success in development of chronic ischemic HF. CONCLUSIONS: The TLD approach, which limits full LAD and collateral flow to its perfusion bed, provides excellent early survival and reliable development of chronic ischemic HF in canine hearts.