[Long term outcome of atrial fibrillation patients with KCNA5 and NPPA mutations post circumferential pulmonary vein ablation].

OBJECTIVE: The outcome of atrial fibrillation patients with genetic mutations post ablation was not well evaluated. METHODS AND RESULTS: Three atrial fibrillation patients with evidence of mutations in KCNA5 and NPPA post successful circumferential pulmonary vein ablation were included. Mutation in KCNA5 was found in one male patient with paroxysmal atrial fibrillation. He was free of atrial fibrillation post ablation after 46 months follow-up. Mutations in NPPA were found in two male patients with persistent atrial fibrillation and they were free from atrial fibrillation after 64 months and 38 months follow-up post circumferential pulmonary vein ablation, roof line and mitral isthmus line ablation. CONCLUSION: Satisfactory long term results are observed in atrial fibrillation patients with KCNA5 and NPPA mutations post circumferential pulmonary vein ablation.

[Predictive value of HATCH score on atrial fibrillation recurrence post radiofrequency catheter ablation].

OBJECTIVE: To determine the predictive value of HATCH score on recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). METHODS: The data of 123 consecutive AF patients (74 paroxysmal and 49 persistent AF) who underwent RFCA between April 2009 and December 2010 in our department were retrospectively analyzed. Of theses patients, 65 (52.9%) patients had HATCH score = 0, 41 (33.3%) patients had HATCH score = 1, and 17 (13.8%) patients had HATCH score ≥ 2 (HATCH = 2 in 11 patients, HATCH = 3 in 5 patients, HATCH = 4 in 1 patient). The recurrence was defined as atrial tachyarrhythmia lasting more than 30 seconds after 3 months post RFCA. The patients were divided into recurrence group and no recurrence group. Relationship between HATCH score and recurrence was observed. RESULTS: There were 43 cases in recurrence group and 80 cases in no recurrence group. After 12 months follow-up, HATCH score was significant higher in recurrence group than in non-recurrence group [(0.91 ± 0.94) score vs. (0.53 ± 0.80) score, P < 0.05]. The ratio of patients with HATCH ≥ 2 in recurrence group was higher than in non-recurrence group [23.3% (10/43) vs. 8.8% (7/80), P < 0.01]. The sensitivity and specificity of HATCH ≥ 2 to define the risk of recurrence was 25.0%, 92.4% respectively. Cumulative non-recurrence rate of patients with HATCH score ≥ 2 was lower than patients with HATCH score = 0 and 1 (P < 0.05). CONCLUSION: Higher HATCH score is associated with increased risk of AF recurrence post RFCA.

Early prediction of clinical scores for left ventricular reverse remodeling using extreme gradient random forest, boosting, and logistic regression algorithm representations.

Objective: At present, there is no early prediction model of left ventricular reverse remodeling (LVRR) for people who are in cardiac arrest with an ejection fraction (EF) of ≤35% at first diagnosis; thus, the purpose of this article is to provide a supplement to existing research. Materials and methods: A total of 109 patients suffering from heart attack with an EF of ≤35% at first diagnosis were involved in this single-center research study. LVRR was defined as an absolute increase in left ventricular ejection fraction (LVEF) from ≥10% to a final value of >35%, with analysis features including demographic characteristics, diseases, biochemical data, echocardiography, and drug therapy. Extreme gradient boosting (XGBoost), random forest, and logistic regression algorithm models were used to distinguish between LVRR and non-LVRR cases and to obtain the most important features. Results: There were 47 cases (42%) of LVRR in patients suffering from heart failure with an EF of ≤35% at first diagnosis after optimal drug therapy. General statistical analysis and machine learning methods were combined to exclude a number of significant feature groups. The median duration of disease in the LVRR group was significantly lower than that in the non-LVRR group (7 vs. 48 months); the mean values of creatine kinase (CK) and MB isoenzyme of creatine kinase (CK-MB) in the LVRR group were lower than those in the non-LVRR group (80.11 vs. 94.23 U/L; 2.61 vs. 2.99 ng/ml; 27.19 vs. 28.54 mm). Moreover, AUC values for our feature combinations ranged from 97 to 94% and to 87% when using the XGBoost, random forest, and logistic regression techniques, respectively. The ablation test revealed that beats per minute (BPM) and disease duration had a greater impact on the model's ability to accurately forecast outcomes. Conclusion: Shorter disease duration, slightly lower CK and CK-MB levels, slightly smaller right and left ventricular and left atrial dimensions, and lower mean heart rates were found to be most strongly predictive of LVRR development (BPM).

[Effects of ventricular demand and dual-chamber pacing models on the long-term clinical outcome and cardiac remodeling in patients with symptomatic bradycardia].

OBJECTIVE: To assess the effects of VVI (ventricular demand) and DDD (dual-chamber) pacing models on cardiac remodeling and the long-term clinical outcome of patients with symptomatic bradycardia. METHODS: All patients with DDD and VVI pacing models at our hospital from January 1991 to January 2003 were retrospectively analyzed. RESULTS: After a follow-up period of over 8 years in DDD and VVI groups (97 ± 27, 107 ± 44 months), left atrial diameter [(45 ± 12) mm vs (39 ± 12) mm, P < 0.01] and left ventricular end-diastolic diameter [(53 ± 11) mm vs (50 ± 9) mm, P = 0.01] in 57 patients with VVI pacing model were markedly enlarged than those at pre-implantation. And tricuspid regurgitation increased (42.4% vs 16.9%, P < 0.05). But in 59 patients with DDD pacing model, except for increased tricuspid regurgitation (42.1% vs 10.5%, P < 0.01), left atrial diameter [(37 ± 5) mm vs. (35 ± 5) mm, P = 0.07] and left ventricular end-diastolic diameter [(47 ± 7) mm vs (47 ± 5) mm, P = 0.32] were not significantly different. Mitral regurgitation significantly increased only in the VVI group (P < 0.01). The increases of left ventricular end-diastolic diameter (P = 0.04), mitral valve (P = 0.02) and tricuspid regurgitation (P < 0.01) were much more pronounced in the VVI group than those in the DDD group. Left ventricular ejection fraction (LVEF) showed no difference with that at pre-implantation (P = 0.11 in DDD group, P = 0.05 in VVI group). But the LVEF value was lower (P = 0.04) while the incidence of thrombosis was higher (P = 0.03) in the VVI group than those in the DDD group at post-implantation. However, the incidence of atrial fibrillation (P = 0.14), hospitalization (P = 0.08) and survival (P = 0.77) showed no significant difference between two groups. CONCLUSION: DDD pacing offers more benefits over VVI pacing through improving cardiac functions and arresting left ventricular remodeling. However, neither groups showed any difference in decreasing mortality rate and hospitalization. Moreover, both pacing modes fail to reverse cardiac electrical and anatomical remodeling. It is imperative to explore more physiological pacing site and rational atrioventricular (AV) interval to improve the prognosis of patients.

[Efficacy of ibutilide for cardioversion of persistent atrial fibrillation during radiofrequency ablation].

OBJECTIVE: The aim of this study was to investigate the efficiency and safety of ibutilide for cardioversion of persistent atrial fibrillation (AF) during radiofrequency ablation. METHODS: Eighteen patients (16 males) with persistent atrial fibrillation were enrolled in this study. All patients underwent circumferential pulmonary vein ablation guided by a Carto three-dimensional mapping system. In addition, linear ablation at the top of the left atrium and the isthmus of mitral valves and complex fractionated atrial electrogram (CAFE) ablation were performed. All patients were still in either atrial fibrillation or atrial flutter after ablation, the patients were treated with 1 mg intravenous ibutilide injection within 10 minutes after unsuccessful ablation. Intravenous injection was stopped in case of sinus rhythm (SR) restoration or occurrence of severe adverse reactions such as ventricular tachycardia. Cardioversion rate within 30 min and adverse reactions within 4 h were observed. Patients were divided into either conversion group or non-conversion group according to whether AF was converted to sinus rhythm within 30 minutes after injection. RESULTS: Eleven patients (61.11%) converted to SR after ibutilide injection. There were no significant differences in gender, age, body mass index, left atrium and left ventricular function between conversion group and non-conversion groups. The average conversion time was (13.80 ± 7.64) min, left atrium scar area ratio was significantly larger in non-conversion group (12.40 ± 11.03)% than in conversion group (5.12 ± 3.83)%, P < 0.05. Ibutilide significantly prolonged the average wavelength of the AF wave (171.8 ± 29.5) ms vs. (242.0 ± 40.0) ms at baseline, P < 0.01. The QT interval at 30 min after ibutilide injection (0.39 ± 0.21) s was significantly longer than before injection (0.51 ± 0.08) s, P < 0.05. There was no serious arrhythmias or other adverse reactions post ibutilide injection. CONCLUSIONS: Ibutilide is highly effective and safe agent for cardioversion in patients underwent unsuccessful ablation. Left atrium scar area ratio is an important determinant for the conversion rate in this cohort.

[Chronic outcome of patients with paroxysmal atrial fibrillation post catheter ablation].

OBJECTIVE: High short-term successful rate was reported for catheter ablation in patients with paroxysmal atrial fibrillation (AF), we analyzed the long-term outcome (success rate, anticoagulation therapy and embolism event, anti-arrhythmic therapy and death post procedure) of catheter ablation for paroxysmal AF in this study. METHODS: From January 2000 to December 2004, 106 consecutive patients with drug-refractory paroxysmal AF underwent catheter ablation and were followed-up for (60.7 + or - 11.8) months. Segmental pulmonary vein isolation (SPVI) was routinely performed by radiofrequency energy under the guidance of circular mapping catheter. The patients were followed up with 24 h-holter, ECG, telephone or letter. Data on recurrence of AF, the anticoagulation medication and the incidence of embolism, anti-arrhythmic therapy were obtained. RESULTS: There were 9 patients lost to follow up. In the remaining 97 patients [65 males, (54.8 + or - 11.2) years old], 3 cases died from cancer, sinus rhythm was maintained in 68 patients (Group S, 72.3%) and AF recurrence evidenced in 26 patients (Group R, 27.7%). In Group S, 56 patients (82.4%) discontinued anticoagulation medication, and 12 patients continued to take aspirin. There was no embolism event in Group S during follow-up. In Group R, 1 patient continued to take warfarin; 11 patients continued to take aspirin and 2 patients suffered from cerebral embolism. Anticoagulation medication was discontinued in 14 patients (53.8%) and 1 patient suffered form cerebral embolism. The incidence of embolism event in Group R is significantly higher than in Group S (P < 0.01). More patients discontinued anti-arrhythmic medication in Group S than in Group R (80.9% vs. 56.0%, P < 0.05). CONCLUSION: Catheter ablation is associated with satisfactory long-term success rate, reduced anti-arrhythmia medication, improved quality of life in patients with paroxysmal AF.

Impact of right upper pulmonary vein isolation on atrial vagal innervation and vulnerability to atrial fibrillation.

BACKGROUND: Based on the hypothesis that pulmonary vein isolation could result in the damage of the epicardial fat pads, this study aimed to investigated the impact of right upper pulmonary vein (RUPV) isolation on vagal innervation to atria. METHODS: Bilateral cervical sympathovagal trunks were decentralized in 6 dogs. Metoprolol was given to block sympathetic effects. Multipolar catheters were placed into the right atrium (RA) and coronary sinus (CS). RUPV isolation was performed via transseptal procedure. Atrial effective refractory period (ERP), vulnerability window (VW) of atrial fibrillation (AF), and sinus rhythm cycle length (SCL) were measured at RA and distal coronary sinus (CSd) at baseline and vagal stimulation before and after RUPV isolation. Serial sections of underlying tissues before and after ablation were stained with haematoxylin and eosin. RESULTS: SCL decreased significantly during vagal stimulation before RUPV isolation (197 +/- 21 vs 13 +/- 32 beats per minute, P < 0.001), but remained unchanged after RUPV isolation (162 +/- 29 vs 140 +/- 39 beats per minute, P > 0.05). ERP increased significantly before RUPV isolation compared with that during vagal stimulation [(85.00 +/- 24.29) ms vs (21.67 +/- 9.83) ms at RA, P < 0.001; (90.00 +/- 15.49) ms vs (33.33 +/- 25.03) ms at CSd P < 0.005], but ERP at baseline hardly changed after RUPV isolation compared with that during vagal stimulation [(103.33 +/- 22.50) vs (95.00 +/- 16.43) ms at RA, P = 0.09; (98.33 +/- 24.83) vs (75.00 +/- 29.50) ms at CSd, P = 0.009]. The ERP shortening during vagal stimulation after RUPV isolation decreased significantly [(63.33 +/- 22.51) ms vs (8.33 +/- 9.83) ms at RA, P < 0.005; (56.67 +/- 20.66) ms vs (23.33 +/- 13.66) ms at CSd, P < 0.05]. AF was rarely induced at baseline before and after RUPV isolation (VW close to 0), while VW of AF to vagal stimulation significantly decreased after RUPV isolation [(40.00 +/- 10.95) vs 0 ms at RA, P < 0.001; (45.00 +/- 32.09) vs (15.00 +/- 23.45) ms at CS, P < 0.05]. The architecture of individual ganglia was significantly altered after ablation. CONCLUSIONS: The less ERP shortening to vagal stimulation and altered architecture of individual ganglia after right upper pulmonary vein isolation indicate that isolation may result in damage of the epicardial fat pads, thereby attenuating the vagal innervation to atria. The decreased vulnerability window of atrial fibrillation indicates that vagal denervation may contribute to its suppression.

Pri-miR-124 rs531564 polymorphism and colorectal cancer risk.

MiR-124 functions as a tumor suppressor and plays an important role in tumorigenesis. A common polymorphism (rs531564, C>G) in the pri-miR-124 has been recently studied in connection with cancer risk. The aim of the present study was to investigate the association between pri-miR-124 rs531564 polymorphism and the risk and clinicopathological characteristics of colorectal cancer (CRC). Two case-control studies involving 900 CRC patients and 1110 cancer-free controls showed that pri-miR-124 rs531564 polymorphism was significantly associated with the decreased risk of CRC in Xuzhou population [GG vs. CC: OR = 0.25, 95%CI = 0.09-0.67, P = 0.003; (CG+GG) vs. CC: OR = 0.73, 95%CI = 0.56-0.94, P = 0.01; GG vs. (CC+CG): OR = 0.27, 95%CI = 0.10-0.70, P = 0.004; G vs. C: OR = 0.70, 95%CI = 0.56-0.89, P = 0.003], Bengbu population [GG vs. CC: OR = 0.20, 95%CI = 0.04-0.90, P = 0.02; GG vs. (CC+CG): OR = 0.21, 95%CI = 0.05-0.95, P = 0.03; G vs. C: OR = 0.72, 95%CI = 0.54-0.98, P = 0.03] and pooled population [GG vs. CC: OR = 0.26, 95%CI = 0.11-0.59, P<0.001; (CG+GG) vs. CC: OR = 0.76, 95%CI = 0.62-0.93, P = 0.008; GG vs. (CC+CG): OR = 0.27, 95%CI = 0.12-0.62, P < 0.001; G vs. C: OR = 0.71, 95%CI = 0.59-0.85, P<0.001]. Additionally, pri-miR-124 rs531564 polymorphism was significantly associated with the decreased risk of poor differentiation and lymph node metastasis of CRC. Our results suggest that pri-miR-124 rs531564 polymorphism may be a genetic modifier for developing CRC. However, further studies are needed to validate our findings.

FEN1 -69G>A and 4150G>T polymorphisms and cancer risk in Chinese population.

Previous studies have investigated the associations between FEN1 -69G>A (rs174538) and 4150G>T (rs4246215) polymorphisms and cancer risk in Chinese population. However, the results were controversial. We therefore carried out a meta-analysis to derive a more precise estimation of the associations. PubMed Database was systematically searched to identify potentially eligible literatures. Crude odds ratios (ORs) and their 95% confidence intervals (CIs) were used to assess the strength of associations between FEN1 -69G>A and 4150G>T polymorphisms and cancer risk in Chinese population. A total of 4 articles, including 5,108 cases and 6,382 controls, were used to evaluate the effect of the two polymorphisms on cancer risk. The pooled ORs indicated that FEN1 -69G>A and 4150G>T polymorphisms were significantly associated with cancer risk in Chinese population. In stratified analyses by cancer type, significant associations were also observed in digestive system cancer. In addition, haplotypes consisting of -69G>A and 4150G>T polymorphisms were closely associated with cancer risk. Interestingly, significantly correlation between FEN1 -69G>A polymorphism and mRNA expression was observed. In conclusion, this meta-analysis suggests that FEN1 -69G>A and 4150G>T polymorphisms may be associated with cancer susceptibility in Chinese population. However, further investigation on large population and different ethnicities are warranted.

The impact of hypertension on the electromechanical properties and outcome of catheter ablation in atrial fibrillation patients.

BACKGROUND: Although hypertension is associated with atrial fibrillation (AF), the impact of hypertension on the electromechanical properties and outcome of catheter ablation in AF patients is unclear. METHODS: AF patients [n=213, 136 paroxysmal AF (PAF) patients and 77 persistent AF patients] undergoing circumferential pulmonary vein (PV) isolation guided by CARTO mapping were enrolled, and then were divided into normotension group and hypertension group. Several left atrial (LA) electroanatomical parameters determined by the CARTO system were compared between groups. RESULTS: The LA bipolar voltage was lower in PAF patients with than without hypertension (1.44±1.09 vs. 1.92±0.76 mV, P=0.048); a significant difference was also observed in persistent AF patients. Hypertension significantly increased the size of the LA scar and low-voltage zones (LVZs) in both PAF and persistent AF patients. However, hypertension did not significantly affect recurrence in either PAF or persistent AF patients. The LA bipolar voltage was higher in PAF patients without recurrence than in those with recurrence (1.77±1.01 vs. 1.29±0.93 mV, P=0.048); a significant difference was also observed in persistent AF patients. PAF and persistent AF patients with AF recurrence had significantly larger LA scar and LVZs than patients without recurrence. CONCLUSIONS: Hypertension has a significant impact on the LA electromechanical properties in AF patients, and the LA substrate has an important influence on the outcome of catheter ablation.

Substrate of complex fractionated atrial electrograms: evidence by pathologic analysis.

BACKGROUND: Ablation of complex fractionated atrial electrograms (CFAE) is an important adjunctive therapy in atrial fibrillation (AF). The present study was to elucidate the substrate underlying CFAE. METHODS: Nine adult mongrel dogs were involved in the present study. AF was induced through rapid atrial pacing with vagosympathetic nerve stimulation. CFAE was recorded during AF. Ablation was performed at CFAE sites. Based on the location of the ablation scar, the atrial specimens were divided into CFAE and non-CFAE sites. Serial sections of the atrium were stained respectively with hematoxylin-eosin (HE) and the general neural marker protein gene product 9.5 (PGP9.5). We compared the characteristics of the myocardium and the ganglionated plexus (GPs) distribution between the CFAE and non-CFAE sites. RESULTS: The myocardium of non-CFAE sites was well-organized with little intercellular substance. However, the myocardium in the CFAE site was disorganized with more interstitial tissue ((61.7 ± 24.3)% vs. (34.1 ± 9.2)%, P < 0.01). GPs in the CFAE site were more abundant than in non-CFAE sites ((34.45 ± 37.46) bundles/cm(2) vs. (6.73 ± 8.22) bundles/cm(2), P < 0.01). CONCLUSION: The heterogeneity of the myocardium and GPs distribution may account for the substrate of CFAE and serve as a potential target of ablation.

Effect of ablation of complex fractionated atrial electrogram on vagal modulation in dogs.

BACKGROUND: Clinical observations have shown that the complex fractionated atrial electrogram (CFAE) associates with ganglionated plexus activity in the cardiac autonomic nervous system. This study aimed to investigate the impact of CFAE ablation on vagal modulation to atria and vulnerability to develop atrial fibrillation (AF). METHODS: Ten adult mongrel dogs were involved. Cervical sympathovagal trunks were decentralized and sympathetic effects were blocked. CFAE was color tagged on the atrial 3-dimensional image and ablated during AF induced by S1S2 programmed stimulation plus sympathovagal trunk stimulation. Atrial effective refractory period (ERP) and vulnerability window (VW) of AF were measured on baseline and at vagal stimulation at 4 atrium sites. Serial tissue sections from ablative and control specimens received hematoxylin and eosin staining for microscopic examination. RESULTS: Most CFAE areas were localized at the right superior pulmonary quadrant, distal coronary sinus (CS(d)) quadrant, and proximal coronary sinus (CS(p)) quadrant (21.74%, separately). Sinus rhythm cycle length (SCL) shortening did not decrease significantly after ablation at the sites, including right atrial appendage, left atrial appendage, CS(d), and CS(p) (P > 0.05). ERP shortening during vagal stimulation significantly decreased after ablation (P < 0.01); the VW to vagal stimulation significantly decreased after ablation (P < 0.05). The architecture of individual ganglia altered after ablation. CONCLUSIONS: CFAE has an autonomic basis in dogs. The decreased SCL and ERP shortening to vagal stimulation after CFAE ablation demonstrate that CFAE ablation attenuates vagal modulation to the atria, thereby suppressing AF mediated by enhanced vagal activity. CFAE ablation could suppress AF mediated by enhanced vagal activity.