Man Ning

Serum uric acid and risk of left atrial thrombus in patients with nonvalvular atrial fibrillation.

BACKGROUND Serum uric acid (SUA) is a simple and independent marker of morbidity and mortality in a variety of cardiovascular diseases. In this study we aimed to investigate SUA and the risk of left atrial (LA) thrombus in patients with nonvalvular atrial fibrillation (AF). METHODS In this retrospective study, 1359 consecutive patients undergoing transesophageal echocardiography before catheter ablation of AF were enrolled. Sixty-one of the 1359 patients (4.5%) had LA thrombus. RESULTS SUA levels in patients with LA thrombus were significantly greater (413.5 ± 98.8 μmol/L vs 366.7 ± 94.3 μmol/L; P < 0.001). Hyperuricemia was defined as SUA ≥ 359.8 μmol/L in women and ≥ 445.6 μmol/L in men determined according to receiver operating characteristic curve. The incidence of LA thrombus was significantly greater in patients with hyperuricemia than in those with a normal SUA level in women (12.1% vs 1.9%; P < 0.001) and in men (8.5% vs 2.8%; P < 0.001). Hyperuricemia had a negative predictive value of 98.1% in women and 97.1% in men for identifying LA thrombus. Hyperuricemia was associated with significantly greater risk of LA thrombus among Congestive Heart Failure, Hypertension, Age ≥ 75 Years, Diabetes Mellitus, Stroke, Vascular Disease, Age 65 to 74 Years, Sex Category (CHA2DS2-VASc) score = 0, 1, and ≥ 2 groups with odds ratios of 7.19, 4.05, and 3.25, respectively. In multivariable analysis, SUA was an independent risk factor of LA thrombus (odds ratio, 1.004; 95% confidence interval, 1.000-1.008; P = 0.028). CONCLUSIONS Hyperuricemia was a modest risk factor for LA thrombus, which might refine stratification of LA thrombus in patients with nonvalvular AF.

Predictors of recurrence after a repeat ablation procedure for paroxysmal atrial fibrillation: role of left atrial enlargement

AIMS This study sought to explore the predictors of recurrence in patients with paroxysmal atrial fibrillation (AF) undergoing repeat catheter ablation, especially the impact of left atrial (LA) remodelling after the original procedure on the outcome of repeat procedure. METHODS AND RESULTS Ninety-five patients undergoing repeat ablation were enrolled in this study. Repeat procedure endpoints were pulmonary vein isolation, linear block when linear ablation is performed, and non-inducibility of atrial tachyarrhythmia by burst pacing. Patients with LA enlargement between the pre-original procedure and pre-repeat procedure were categorized as Group 1 (35 patients), while individuals with no change or decrease of LA diameter were categorized as Group 2 (60 patients). The mean duration from the original procedure to the repeat procedure was 12 months (1-40 months). After 29.6 ± 20.5 (3-73) months follow-up from the repeat procedure, 33 patients experienced recurrence (34.7%). The recurrence rate was significantly higher in Group 1 than in Group 2 (51.4 VS. 25.0%, P = 0.017). In univariate analysis, LA remodelling was the only predictor of recurrence. In multivariate analysis, after adjustment for age and LA diameter, Group 1 had a greater risk of recurrence after the repeat procedure (hazard ratio = 2.22, 95% confidence interval: 1.02-4.81, P = 0.043). CONCLUSIONS Left atrial enlargement after undergoing the original catheter ablation of paroxysmal AF was an independent risk factor of recurrence after repeat ablation.

A New Method to Evaluate Linear Block at the Left Atrial Roof: Is It Reliable Without Pacing?

A New Method to Evaluate Linear Block at the Left Atrial Roof. Objective: The present study aimed to evaluate a new method for validation of complete linear block at the left atrial (LA) roof.

Isolated Conduction Within the Left His-Purkenje System During Sinus Rhythm and Idiopathic Left Ventricle Tachycardia Findings From Mapping the Whole Conduction System

Background—Functionally, left His-Purkenje system (HPS) is insulated from the adjacent myocardium and exhibits isolated conduction during sinus rhythm (SR), but in vivo human study is rare. Meanwhile, whether the isolated conduction also exists during idiopathic left ventricle tachycardia (ILVT) is not clearly defined. The current study aimed to delineate the activation sequence and gross anatomy of left HPS during SR and ILVT. Methods and Results—The study involved 25 consecutive patients with ILVT. During SR, left HPS exhibited antegrade activation sequence, and its surrounding myocardium depolarized after HPS in an apical to base direction. During ILVT, the earliest retrograde presystolic potentials were mainly located at the middle portion of left posterior fascicle (0.5±0.1 [95% confidence interval, 0.46–0.58] of its full length) with an average of 29.5±6.0 mm (19.8–41.5) away from the His position. Left posterior fascicle was depolarized from the earliest retrograde presystolic potentials via 2 opposite wavefronts with significantly shorter activation time than that during SR (15.1±2.1 versus 30.0±3.2 ms; P<0.001). The left anterior fascicle was depolarized after left posterior fascicle with an antegrade activation sequence and comparable activation time with that during SR (21.9±2.9 versus 22.0±4.1 ms; P=0.932). The depolarization of ventricle septum also occurred after HPS in an apical to base direction. Conclusions—During SR, isolated conduction within the HPS is demonstrated by documenting the reverse activation sequence with its surrounding myocardium. During ILVT, the earliest retrograde presystolic potentials were usually recorded at the middle segment of left posterior fascicle, and the isolated conduction within the HPS remained.

Ablation of Right-Sided Accessory Pathways With Atrial Insertion Far From the Tricuspid Annulus Using an Electroanatomical Mapping System

Ablating Right‐Sided Accessory Pathways With Atrial Insertions Far From Tricuspid Annulus. Background: It is difficult to ablate a right‐sided accessory pathway (AP) with atrial insertion far from the tricuspid annulus (TA). We report our initial experience of ablating this rare AP by a 3‐dimensional electroanatomical mapping system (CARTO).

Significant Left Atrial Appendage Activation Delay Complicating Aggressive Septal Ablation during Catheter Ablation of Persistent Atrial Fibrillation

Background:  This study aims to describe significant left atrial appendage activation following ablation of persistent atrial fibrillation, and explore its relationship with aggressive septal ablation.

Incidence and clinical characteristics of transient ST-T elevation during transseptal catheterization for atrial fibrillation ablation

AIMS Transient ST-T elevation (STE) is a rare complication that occurs during transseptal catheterization. This study aims to delineate the incidence and characteristics of transient STE during transseptal catheterization for atrial fibrillation (AF) ablation. METHODS AND RESULTS Consecutive patients who underwent fluoroscopy-guided transseptal catheterization for circumferential pulmonary vein radiofrequency ablation in Beijing An Zhen Hospital from January 2006 to January 2013 were enrolled in this study. Out of 2965 patients with a total of 3452 transseptal catheterization procedures, 13 patients (0.38%, mean age 57 ± 8, 6 female, 12 paroxysmal AF, mean left atrial diameter 35.4 ± 3.8 mm) had STE. ST-T elevation occurred after transseptal puncture in 10 patients and after pulmonary vein venography in three patients. Systolic blood pressure (129 ± 10 vs. 104 ± 20 mmHg, P < 0.001), diastolic blood pressure (78 ± 6 vs. 64 ± 11 mmHg, P < 0.001), and heart rate (83 ± 19 bpm vs. 64 ± 23 b.p.m., P = 0.022) significantly decreased when STE occurred. Eleven patients complained of chest pain, one patient complained of dizziness, and one patient had no symptoms. Patients recovered in about 4.6 min (2-10 min) with dopamine or fast saline drip. Catheter ablation of AF was completed in all the 13 patients without sequelae or other complications. Four of the 13 patients (30.8%) had recurrence of AF after a mean follow-up of 21.7 months. CONCLUSION ST-T elevation is a rare complication associated with transseptal catheterization without sequelae. Catheter ablation of AF could be safely completed in these patients.

Isolated Conduction Within the Left His-Purkenje System During Sinus Rhythm and Idiopathic Left Ventricle TachycardiaClinical Perspective

Background—Functionally, left His-Purkenje system (HPS) is insulated from the adjacent myocardium and exhibits isolated conduction during sinus rhythm (SR), but in vivo human study is rare. Meanwhile, whether the isolated conduction also exists during idiopathic left ventricle tachycardia (ILVT) is not clearly defined. The current study aimed to delineate the activation sequence and gross anatomy of left HPS during SR and ILVT. Methods and Results—The study involved 25 consecutive patients with ILVT. During SR, left HPS exhibited antegrade activation sequence, and its surrounding myocardium depolarized after HPS in an apical to base direction. During ILVT, the earliest retrograde presystolic potentials were mainly located at the middle portion of left posterior fascicle (0.5±0.1 [95% confidence interval, 0.46–0.58] of its full length) with an average of 29.5±6.0 mm (19.8–41.5) away from the His position. Left posterior fascicle was depolarized from the earliest retrograde presystolic potentials via 2 opposite wavefronts with significantly shorter activation time than that during SR (15.1±2.1 versus 30.0±3.2 ms; P<0.001). The left anterior fascicle was depolarized after left posterior fascicle with an antegrade activation sequence and comparable activation time with that during SR (21.9±2.9 versus 22.0±4.1 ms; P=0.932). The depolarization of ventricle septum also occurred after HPS in an apical to base direction. Conclusions—During SR, isolated conduction within the HPS is demonstrated by documenting the reverse activation sequence with its surrounding myocardium. During ILVT, the earliest retrograde presystolic potentials were usually recorded at the middle segment of left posterior fascicle, and the isolated conduction within the HPS remained.

QTc Interval Prolongation Predicts Arrhythmia Recurrence After Catheter Ablation of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

BACKGROUND In hypertrophic cardiomyopathy (HCM) patients complicated with atrial fibrillation (AF), catheter ablation has been recommended as a treatment option. Meanwhile, prolongation of QTc interval has been linked to an increased AF incidence in the general population and to poor outcomes in HCM patients. However, whether QTc prolongation predicts arrhythmia recurrence after AF ablation in the HCM population remains unknown. METHODS AND RESULTS Thirty-nine HCM patients undergoing primary AF ablation were enrolled. The ablation strategy included bilateral pulmonary vein isolation (PVI) for paroxysmal AF (n=27) and PVI plus left atrial roof, mitral isthmus and tricuspid isthmus linear ablations for persistent AF (n=12). Pre-procedural QTc was corrected by using the Bazetts formula. At a 14.8-month follow up, 23 patients experienced atrial tachyarrhythmia recurrence. Recurrent patients had longer QTc than non-recurrent patients (461.0±28.8 ms vs. 434.3±18.2 ms, P=0.002). QTc and left atrial diameter (LAD) were independent predictors of recurrence. The cut-off value of QTc 448 ms predicted arrhythmia recurrence with a sensitivity of 73.9% and a specificity of 81.2%. A combination of LAD and QTc (global chi-squared=13.209) was better than LAD alone (global chi-squared=6.888) or QTc alone (global chi-squared=8.977) in predicting arrhythmia recurrence after AF ablation in HCM patients. CONCLUSIONS QTc prolongation is an independent predictor of arrhythmia recurrence in HCM patients undergoing AF ablation, and might be useful for identifying those patients likely to have a better outcome following the procedure.

Ablation of left-sided accessory pathways with atrial insertion away from the mitral annulus using an electroanatomical mapping system.

A left‐sided accessory pathway (AP) with atrial insertion away from the mitral annulus (MA) may result in difficulty or failed ablation along the MA. We report our initial experience of ablating this rare form of AP by a 3‐dimensional electroanatomical mapping system (CARTO).