Circulating primary bile acid is correlated with structural remodeling in atrial fibrillation.

BACKGROUND: Circulating primary bile acid was involved in the regulation of cardiac ionic channel currents and ventricular myocyte apoptosis, but it was unknown whether or not it played a role in structural remodeling of AF. This study was aimed to testify the hypothesis that elevated chenodeoxycholic acid (CDCA) concentration correlated with left atrial low voltage area (LVA) and could induce apoptosis of atrial myocytes in AF. METHODS AND RESULTS: Serum concentrations of 12 types of bile acids were determined in patients with paroxysmal (n = 21), persistent AF (n = 20), and type A pre-excitation and paroxysmal supraventricular tachycardia (PSVT) (n = 19) and were correlated with LVA in AF, which was obtained by electroanatomical mapping during ablation. Additionally, the impact of CDCA incubation on apoptosis of mouse atrial myocytes was evaluated. Serum levels of CDCA and cholic acid were significantly higher in AF than in PSVT. CDCA serum concentration was significantly higher in persistent AF than in paroxysmal AF. CDCA serum level was positively correlated with the size (r = 0.78, P < 0.05) and proportion of LVA (r = 0.89, P < 0.05) in AF patients. CDCA (75 µM, 100 µM) promoted atrial myocyte apoptosis in a concentration-dependent manner. CONCLUSIONS: The higher circulating level of CDCA in AF than in PSVT, positive correlation of CDCA with LVA in AF, and incubation dose-dependent increase of mouse atrial myocyte apoptosis indicated that CDCA might play a significant role in the progress of structural remodeling of AF.

Low voltage areas in paroxysmal atrial fibrillation: The prevalence, risk factors and impact on the effectiveness of catheter ablation.

BACKGROUND: The prevalence, risk factors of left atrial low voltage areas (LVA) in paroxysmal atrial fibrillation (PAF) and the impact of LVA on the effectiveness of circumferential pulmonary vein isolation (CPVI) were not fully clarified. METHODS: One hundred fifty patients (mean age 64.7 years, 89 males) with PAF were consecutively enrolled to undergo CPVI. Prior to ablation a contact force sensing ablation catheter was utilized for LVA mapping in sinus rhythm. The patients were graded based on the proportion of LVA (LVA%): non LVA, mild (LVA% ≤ 10%), moderate (LVA% 10%-<20%) and severe (LVA% ≥ 20%), and were followed up for 12 months after initial CPVI. RESULTS: There were 56 in non LVA, 54 in mild LVA, 22 in moderate LVA and 18 in severe LVA. The prevalence of LVA was 62.7% in this PAF cohort, with the most frequent localization at anterior free wall (35.3%), PV antrum (22%) and septum (14.7%). Female gender (OR 3.634, 95% CI 1.704-7.751, P = 0.001) and left atrial surface area (LASA) (OR 1.024, 95% CI 1.000-1.048, P = 0.048) were risk factors of LVA. LVA% exceeding10% was associated with poor effectiveness of CPVI. LVA grade (HR 1.633, 95% CI 1.122-2.378, P = 0.011) was an independent predictor for AF recurrence after initial ablation. CONCLUSIONS: LVA affected >60% of patients with PAF. Female gender and LASA were two risk factors of LVA. LVA grade was an independent predictor for AF recurrence following CPVI.

[Clinical results of circumferential pulmonary vein linear ablation in 100 patients with atrial fibrillation].

OBJECTIVE: To investigate the feasibility and efficacy of treating atrial fibrillation (AF) with circumferential pulmonary vein (PV) linear ablation guided by 3 dimensional mapping system and single circular mapping catheter. METHODS: From April 2004 to January 2005, PV isolation with circumferential PV linear ablation guided by CARTO system (in 76 patients) or EnSite-NavX system (in 24 patients) was performed in 100 consecutive patients with significantly symptomatic, drug refractory AF. The procedural end-point was complete electrical isolation of bilateral PV. RESULTS: Up to 200 linear circles were produced around each ipsilateral PVs in all 100 cases, and 95.0% (190/200) of PV isolation rate was achieved with a mean procedure time of 150-365 (240 +/- 65) min and a mean fluoroscopy time of 23-61 (37 +/- 12) min, respectively. Eight cases with recurrent AF (8.0%) underwent second session. Cumulative atrial tachyarrhythmias-free rate was 85.0% (85/100) during a mean follow-up of 5.5-12 (10.2 +/- 5.7) months. Atrial tachyarrhythmias-free rate was 66.0% (66/100), 82.0% (82/100), 87.0% (87/100), 85.0% (85/100), 85.0% (85/100), and 88.6% (70/79) during the follow up at 1 month, 2 months, 3 months, 4 months, 5 months and 6 months, respectively. There were 2 complications (1 tamponade and 1 PV stenosis), which were rehabilitated after conservative treatment. CONCLUSION: PV isolation with circumferential PV linear ablation guided by 3 dimensional mapping system is safe and effective for treating AF.