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Some patients with persistent atrial fibrillation (AF) acquire long-term freedom from AF by pulmonary vein (PV) isolation alone. The aim of the present study was to evaluate the characteristics of their atrial substrate.We studied 20 patients with persistent AF to examine the distribution of fractionated atrial potentials (FAP) and that of the anatomic sites of ganglionated plexi (GPs) with vagal reflexes elicited by high frequency stimulation (HFS) with the use of the CARTO system before and after the PV isolation.Both the %FAP area defined as a proportion of the FAP area to the total left atrial area (34.3 ± 10.3 to 21.5 ± 10.2%; P0.0001) and number of GP sites with vagal reflexes (4.0 [3.0, 5.0] to 2.0 [1.0, 2.8]; P0.0001) were markedly decreased after the PV isolation. Seven (35%) patients had AF recurrences, and they had a greater %FAP area after the PV isolation than those without (32.8 [22.1, 37.3] versus 13.8 [10.9, 19.9]%; P = 0.0049). A %FAP area after the PV isolation of20% was significantly associated with an AF recurrence (odds ratio 20.0, 95% confidence interval 2.26470.34; P = 0.018). No significant difference was found between the patients with and without AF recurrence in the reduction rate of anatomic sites of GPs with a vagal reflex induced by the HFS.A more marked reduction in the FAP area by the PV isolation was significantly associated with a better outcome in patients with persistent AF.

Aims Procedural sedation by non-anaesthesiologists with GABAergic anaesthetics has the potential risk of fatal respiratory depression. Dexmedetomidine works its sedative action via α2-adrenergic receptors, and is less associated with respiratory depression. We tested the usability of dexmedetomidine as a procedural sedative during ablation of atrial fibrillation (AF). Methods and results Consecutive patients were randomized to be treated with dexmedetomidine ( n = 43) or thiamylal ( n = 44) as sedatives during AF ablation. Apnoeic and body movement events were monitored using a novel portable respiratory monitor, the SD-101, during the procedure. Although the majority of the patients receiving dexmedetomidine required rescue sedations with thiamylal, the respiratory disturbance index (RDI) defined as the total number of sleep-disordered breathing events divided by the recording time (10.4 ± 5.1 vs. 18.2 ± 8.1 events/h; P < 0.0001) and movement index defined as the number of body movement events per hour (7.6 ± 6.1 vs. 11.0 ± 5.5 events/h; P = 0.0098) were both significantly lower in the dexmedetomidine arm than in the thiamylal arm. A multivariate linear regression analysis including potential factors revealed that dexmedetomidine vs. thiamylal was solely and independently associated with the RDI ( β = −0.62; P = 0.0031). The occurrence of hypotension [9 (21%) vs. 4 (9%); P = 0.14] and bradycardia [4 (9%) vs. 4 (9%); P = 1.0] were similar in the patients with dexmedetomidine and thiamylal. Conclusion Procedural sedation with dexmedetomidine may assure safety and patient immobility during AF ablation, and therefore may be a potential alternative for that with GABAergic anaesthetics.

Two new oral anticoagulants, rivaroxaban and dabigatran, with no need for anticoagulation monitoring, are available for patients with atrial fibrillation (AF). We aimed to compare their anticoagulant effects and safety when used during the AF ablation periprocedural period. Patients undergoing AF ablation were randomly assigned to receive rivaroxaban 15 mg once daily (N = 30) or dabigatran 110 mg twice daily (N = 30). Rivaroxaban was withheld on the morning of the day before the ablation, and dabigatran was discontinued from the evening of the day before the procedure. Both anticoagulants were then resumed after haemostasis of the access site. D-dimer levels were measured just before the ablation, at the end of the ablation, and at 24 h and 48 h after the procedure. The baseline D-dimer levels were identical in both groups. However, D-dimer levels increased more markedly following the ablation procedure in patients receiving rivaroxaban than in those receiving dabigatran (mean ± standard deviation from 0.62 ± 0.16 to 1.09 ± 0.38 μg/mL vs from 0.59 ± 0.08 to 0.75 ± 0.17 μg/mL; p

Background Inappropriate shocks resulting from atrial tachyarrhythmias are highly problematic for patients with an implantable cardioverter defibrillator (ICD). We aimed to determine the effectiveness of catheter ablation of atrial fibrillation (AF) in preventing inappropriate shocks due to rapid AF in patients diagnosed with Brugada syndrome (BS) who were implanted with an ICD. Methods We performed AF ablation in 5 BS patients with ICDs who experienced inappropriate shocks caused by rapid paroxysmal AF and in a BS patient scheduled to determine an indication of an ICD implantation who frequently experienced rapid AF. Results Although 2 patients underwent a 2nd ablation procedure because of AF recurrences, 5 of the 6 patients were finally free from AF after their last procedure during a median follow-up period of 43.2months. No further inappropriate shocks caused by rapid AF occurred after the 1st ablation session in any of the patients. A patient developed a ventricular fibrillation storm during his electrophysiological study following the ablation procedure, and then was implanted with an ICD. Conclusions AF ablation in BS patients may be reasonable to prevent inappropriate ICD shocks resulting from rapid AF. However, ventricular extrastimuli just after the ablation had better be avoided in them.

Variable Strategies for CTI Ablation Objectives This study aimed to investigate the anatomical characteristics complicating cavotricuspid isthmus (CTI) ablation and the effectiveness of various procedural strategies. Methods and Results This study included 446 consecutive patients (362 males; mean age 60.5 ± 10.4 years) in whom CTI ablation was performed. A total of 80 consecutive patients were evaluated in a preliminary study. The anatomy of the CTI was evaluated by multidetector row-computed tomography (MDCT) prior to the procedure. A multivariate logistic regression analysis revealed that the angle and mean wall thickness of the CTI, a concave CTI morphology, and a prominent Eustachian ridge, were associated with a difficult CTI ablation (P < 0.01). In the main study, 366 consecutive patients were divided into 2 groups: a modulation group (catheter inversion technique for a concave aspect, prominent Eustachian ridge, and steep angle of the CTI or increased output for a thicker CTI) and nonmodulation group (conventional strategy). The duration and total amount of radiofrequency energy delivered were significantly shorter and smaller in the modulation group than those in the nonmodulation group (162.2 ± 153.5 vs 222.7 ± 191.9 seconds, P < 0.01, and 16,962.4 ± 11,545.6 vs 24,908.5 ± 22,804.2 J, P < 0.01, respectively). The recurrence rate of type 1 atrial flutter after the CTI ablation in the nonmodulation group was significantly higher than that in the modulation group (6.3 vs 1.7%, P = 0.02). Conclusion Changing the procedural strategies by adaptating them to the anatomical characteristics improved the outcomes of the CTI ablation.

Variable Strategies for CTI Ablation Objectives This study aimed to investigate the anatomical characteristics complicating cavotricuspid isthmus (CTI) ablation and the effectiveness of various procedural strategies. Methods and Results This study included 446 consecutive patients (362 males; mean age 60.5 ± 10.4 years) in whom CTI ablation was performed. A total of 80 consecutive patients were evaluated in a preliminary study. The anatomy of the CTI was evaluated by multidetector row-computed tomography (MDCT) prior to the procedure. A multivariate logistic regression analysis revealed that the angle and mean wall thickness of the CTI, a concave CTI morphology, and a prominent Eustachian ridge, were associated with a difficult CTI ablation (P < 0.01). In the main study, 366 consecutive patients were divided into 2 groups: a modulation group (catheter inversion technique for a concave aspect, prominent Eustachian ridge, and steep angle of the CTI or increased output for a thicker CTI) and nonmodulation group (conventional strategy). The duration and total amount of radiofrequency energy delivered were significantly shorter and smaller in the modulation group than those in the nonmodulation group (162.2 ± 153.5 vs 222.7 ± 191.9 seconds, P < 0.01, and 16,962.4 ± 11,545.6 vs 24,908.5 ± 22,804.2 J, P < 0.01, respectively). The recurrence rate of type 1 atrial flutter after the CTI ablation in the nonmodulation group was significantly higher than that in the modulation group (6.3 vs 1.7%, P = 0.02). Conclusion Changing the procedural strategies by adaptating them to the anatomical characteristics improved the outcomes of the CTI ablation.

Background Sleep-disordered breathing (SDB) frequently is induced by sedation during ablation of atrial fibrillation (AF). We tested whether or not sedative-induced SDB is associated with clinical sleep apnea syndrome (SAS). Methods We examined SDB observed during intra-ablation sedation with a novel portable respiratory monitor (PM), SD-101, in 140 patients undergoing AF ablation without any known SAS. A sleep study was repeated the next night of the ablation with the simultaneous use of the SD-101 and type 3 PM, APNOMONITOR V. Results The respiratory disturbance index (RDI) during sedation (20.0±7.8events/h) was significantly correlated with the RDI measured by the SD-101 during the night (15.8±13.7events/h; r =0.50) and the RDI assessed by the APNOMONITOR V during the night (12.7±12.3events/h; r =0.55). An excellent agreement was found between the RDIs simultaneously measured with the 2 PMs (intraclass correlation coefficient, 0.84), especially for an RDI of ⩾30events/h ( κ statistic value, 0.82). The area under the receiver-operating characteristic curve for the RDI with the use of the SD-101 during sedation to identify the patients with an RDI of ⩾30events/h by both PMs during the night was 0.92. A left atrial diameter of >40mm (odds ratio [OR], 4.10) and an RDI during sedation of >20events/h (OR, 17.75) were independently associated with having an RDI of ⩾30events/h with both PMs during the night. Conclusions Frequent episodes of sedative-induced SDB may have a diagnostic value for SAS in patients with AF.

Background Alcohol consumption and oxidative stress are well-known risk factors for developing atrial fibrillation (AF). Single nucleotide polymorphisms (SNPs) of alcohol dehydrogenase (ADH1B) and aldehyde dehydrogenase 2 (ALDH2) genes encoding enzymes of alcohol and reactive aldehyde metabolism, respectively, are prevalent among East Asians. Here, we examined whether these SNPs were associated with AF in Japanese patients. Methods and results Five hundred seventy-seven Japanese patients with AF undergoing catheter ablation and 1935 controls at Hiroshima University Hospital were studied. Alcohol consumption habits, medical history, electrocardiogram (EKG), electrophysiology and cardiac echocardiography were reviewed. Patients were also genotyped for ALDH2 (rs671) and ADH1B (rs1229984). A significant linear correlation was found between ALDH2 genotype and mean alcohol intake (P = 1.7 × 10−6). Further, ALDH2 (rs671) was associated with AF (P = 7.6 × 10−4, odds ratio [OR] = 0.6). Frequency of the ALDH2 SNP allele A which limits acetaldehyde metabolism was lower in patients with AF (18.8%) than in controls (23.5%). In contrast, we found that the frequencies of the ADH1B SNP genotypes were similar in patients with AF and in controls. Subset analysis among the 182 patients with lone AF and 914 controls (control II) (

It has been reported that dexmedetomidine (dex) has an impact on the cardiac conduction system and even has potential antiarrhythmic actions. We examined the influence of dex on the cardiac electrophysiological properties and atrial fibrillation (AF) inducibility. Adult paroxysmal AF patients were randomly assigned to receive (N = 107) or not receive (N = 108) dex during cardiac electrophysiological studies. The corrected sinus node recovery time (558 ± 331 vs. 459 ± 260 milliseconds; P = 0.02), Wenckebach cycle length (P < 0.001), atrioventricular nodal effective refractory period (317 ± 76 vs. 252 ± 54 milliseconds; P < 0.001), and atrio-His interval (P < 0.001) were longer in patients with dex than in those without. We tested the induction of repetitive atrial firing (RFA) defined as the occurrence of ≥2 successive atrial activities induced by single premature atrial stimuli to determine the AF inducibility. RFA was seen with a similar proportion (41.1% vs. 44.4%), yet it was evoked at a longer stimulus coupling interval in the dex patients, which was potentially attributed to the longer atrial effective refractory period (237 ± 36 vs. 213 ± 27 milliseconds; P < 0.001) and more prolonged atrial conduction delay seen in the dex group. In conclusion, dex may depress the sinus and atrioventricular nodal function, however, it may not reduce the AF inducibility.

Aims Sarcoidosis with cardiac involvement is a rare pathological condition, and therefore cardiac resynchronization therapy (CRT) for patients with cardiac sarcoidosis is even further rare. We aimed to clarify the clinical features of patients with cardiac sarcoidosis who received CRT. Methods and results We retrospectively reviewed the clinical data on CRT at three cardiovascular centres to detect cardiac sarcoidosis patients. We identified 18 (8.9%) patients with cardiac sarcoidosis who met the inclusion criteria out of 202 with systolic heart failure who received CRT based on the guidelines. The majority of the patients were female [15 (83.3%)] and underwent an upgrade from a pacemaker or implantable cardioverter defibrillator [13 (72.2%)]. We found 1 (5.6%) cardiovascular death during the follow-up period (mean ± SD, 4.7 ± 3.0 years). Seven (38.9%) patients had a composite outcome of cardiovascular death or hospitalization from worsening heart failure within 5 years after the CRT. Twelve (66.7%) patients had a history of sustained ventricular arrhythmias or those occurring after the CRT. Among the overall patients, no significant improvement was found in either the end-systolic volume or left ventricular ejection fraction (LVEF) 6 months after the CRT. A worsening LVEF was, however, more likely to be seen in 5 (27.8%) patients with ventricular arrhythmias after the CRT than in those without (P = 0.04). An improved clinical composite score was seen in 10 (55.6%) patients. Conclusions Cardiac sarcoidosis patients receiving CRT may have poor LV reverse remodelling and a high incidence of ventricular arrhythmias.

Cancer therapeutics-related cardiac dysfunction induced by anthracycline is highly problematic, and its early recognition is of importance. Atrial fibrillation (AF) is sometimes seen after anthracycline chemotherapy. We aimed to test whether new-onset AF predicts anthracycline-induced heart failure. We prospectively studied 249 lymphoma patients who received anthracyclines. The patients were followed up with a frequent electrocardiographic examination. Fifteen patients (6%) newly developed AF after the chemotherapy, and during a mean follow-up of 34 months, they had a higher incidence of acute heart failure (40% vs 3.8%; p0.001) and greater all-cause mortality (60% vs 14.1%; p0.001) than those without AF. The onset of AF preceded the development of heart failure by a mean of 2.4 months. New-onset AF was independently associated with both acute heart failure (hazard ratio 12.78; p0.001) and all-cause mortality (hazard ratio 4.77; p0.001). The cumulative anthracycline dose did not differ between the patients with and without heart failure, yet it was another independent predictor of the mortality. In conclusion, new-onset AF may predict unfavorable outcomes after anthracycline chemotherapy in patients with malignant lymphoma.

An animal experiment showed that long-term atrial pacing or persistent atrial fibrillation (AF) caused electrical remodeling of the atrioventricular (AV) node. We aimed to test the hypothesis that persistent AF decreases the AV conductivity in human hearts.We retrospectively compared the cardiac electrophysiological properties between patients with paroxysmal AF who underwent catheter ablation (PXAF, N = 254) and those with persistent or longstanding persistent AF (PSAF, N = 213). The PSAF patients were more likely than PXAF patients to have longer atrial-His (AH) (96.3 ± 25.7 vs. 91.3 ± 20.4 milliseconds; P = 0.02) and His-ventricle (HV) (43.1 ± 9.4 vs. 41.2 ± 8.6 milliseconds; P = 0.02) intervals. The AV nodal effective refractory period (ERP) (299.1 ± 74.6 vs. 276.2 ± 58.9 milliseconds; P0.001) and Wenckebach cycle length (420.9 ± 80.3 vs. 386 ± 58.6 milliseconds; P0.001) were also more prolonged in the PSAF patients. We found a dual AV nodal physiology with a similar frequency in both groups. The AH interval, fast pathway ERP, and Wenckebach cycle length in the PSAF patients were more likely than in the PXAF patients to be prolonged among the patients without dual pathways, while those intergroup differences were never seen among the patients with dual pathways. In subgroup analyses including only PSAF patients, there was no difference in the AV conductivity between the patients with persistent AF and those with longstanding persistent AF.Persistent AF may cause a mild decrease in the AV nodal function in human hearts. Electrical remodeling may be uncommon if dual AV nodal pathways are present, and its extent may not depend on the duration of persistent AF.

Background— Risk stratification of Brugada syndrome (BrS) remains controversial and the majority of patients with BrS have no genetic explanation. We investigated relationships between genotypes of 3 single-nucleotide polymorphisms reported in a recent genome-wide association study and BrS phenotypes. Methods and Results— SCN10A (rs10428132), SCN5A (rs11708996), and downstream from HEY2 (rs9388451) single-nucleotide polymorphisms were genotyped and compared between 95 Japanese patients with BrS and 1978 controls. Relationships between the single-nucleotide polymorphisms and clinical characteristics, 12-lead ECG findings, signal-averaged ECG findings, and electrophysiological parameters were also examined in patients with BrS. Both rs10428132 and rs9388451 were significantly associated with BrS ( P =2.7×10 −14 ; odds ratio, 3.0; P =9.2×10 −4 ; odds ratio, 1.7, respectively). Interestingly, the HEY2 risk allele C was less frequent in BrS patients with ventricular fibrillation than in those without (59% versus 74%; P =4.1×10 −2 ; odds ratio, 0.5). A significant linear correlation was found between HEY2 genotypes and QTc interval (CC: 422±27 ms; CT: 408±21 ms; and TT: 381±27 ms; P = 4.0×10 −4 ). The HEY2 mRNA expression level in the right ventricular specimens from patients with BrS (n=20) was significantly lower in patients with CC genotype than the other genotypes ( P =0.04). Additionally, during 63±28 months follow-up periods after implantable cardioverter defibrillator implantation (n=90), Kaplan–Meier event-free survival curves revealed that the cumulative rate of ventricular fibrillation events was significantly lower in cases with HEY2 CC genotype ( P =0.04). Conclusions— Our findings suggest that HEY2 CC genotype may be a favorable prognostic marker for BrS, protectively acting to prevent ventricular fibrillation presumably by regulating the repolarization current.

Background We aimed to evaluate the feasibility of an oral direct thrombin inhibitor, dabigatran, as a periprocedural anticoagulant for use with ablation of atrial fibrillation (AF). Methods Consecutive patients scheduled to undergo an AF ablation were randomly assigned to receive dabigatran (n = 45) or warfarin (n = 45) to compare their clinical feasibility. Both of those oral anticoagulants were discontinued the day before the ablation and were resumed after confirming hemostasis of the venipuncture site. A bridging therapy with heparin was not used in either of the patient groups. Results Dabigatran was switched to warfarin before the ablation because of dyspepsia in three patients. An occurrence of rebleeding from the venipuncture site was less common in dabigatran-allocated patients than in warfarin-allocated patients (20% vs 44%; P = 0.013). The reduction in the D-dimer level after the initiation of oral anticoagulants was greater in the dabigatran-allocated patients than in the warfarin-allocated patients. The time from the initiation of the anticoagulants to the ablation was significantly shorter in the dabigatran-allocated patients than in the warfarin-allocated patients (43 ± 7 vs 63 ± 13 days; P < 0.0001). There was only one fatal periprocedural complication in a patient receiving warfarin, who had a mesenteric arterial thrombosis after the ablation. Conclusions An anticoagulation strategy with dabigatran may surpass that with warfarin in reducing both the periprocedural risk of minor bleeding and a hypercoagulable state, and the time to ablation in patients undergoing ablation of AF.

Background The indications for catheter ablation have been expanded to include persistent atrial fibrillation (AF) to enable a high degree of sinus rhythm maintenance. We occasionally encounter patients undergoing pacemaker implantation in whom sick sinus syndrome became clinically evident after ablation. This study investigated whether underlying sinus node dysfunction (SND) during persistent AF can be predicted before deciding the indications for ablation. Methods and results In total, 87 consecutive patients with persistent AF who underwent catheter ablation between January 2010 and July 2011 were enrolled in the study. Nocturnal polysomnography as well as transthoracic and transesophageal echocardiography were performed in all patients before ablation. We used the double Lasso catheter and electroanatomical mapping-guided extensive encircling pulmonary vein isolation (EEPVI) method. We performed electrophysiological studies after EEPVI, and SND was defined as a corrected SN recovery time of ≥550 ms. SND was detected in 42 (48%) patients (SND group); the other patients showed normal sinus node function (NSN group). The apnea/hypopnea index (AHI) was significantly greater in the SND group than in the NSN group (25.7 ± 13 vs. 17.5 ± 11, p = 0.002). Multivariate analysis revealed that moderate to severe sleep-disordered breathing (defined as AHI ≥ 15) was an independent predictor of SND after catheter ablation for persistent AF. Conclusion The results suggest that underlying SND in patients with persistent AF can be predicted by evaluating sleep-disordered breathing before catheter ablation.

High-frequency stimulation (HFS) of the atria induces atrial fibrillation (AF) when applied during sinus rhythm and elicits a parasympathetic response when delivered at sites where ganglionated plexi (GPs) are located. However, little is known about its impact after an electrophysiological study.To evaluate the impact of HFS on the short-term and long-term outcomes after the ablation of persistent AF.Thirty consecutive patients with persistent or long-standing persistent AF were randomly assigned to either receive HFS of the left atrium (n = 15) or not (n = 15) during their electrophysiological studies. Patients receiving HFS were examined to determine whether or not a vagal response was elicited by the HFS at sites where GPs were located before and after conventional pulmonary vein isolation without any ablation targeting the GPs. Patients not receiving the HFS underwent the ablation procedure alone. The rate of recurrence of AF within 3 months of the procedure (early recurrence [ER]) and the frequency of that occurring after that period (late recurrence) were compared between the patient groups.The incidence of ER occurred more frequently in patients with HFS than in those without (80% vs 40%; P = .015), whereas the occurrence of late recurrence was similar between the 2 groups (27% vs 33%; P = .73). In the HFS group, the number of GPs decreased from 3.4 ± 1.1 to 1.5 ± 0.8 after the pulmonary vein isolation (P.0001), and the decrease was smaller in the patients experiencing ER than in those without.HFS increases the incidence of ER in patients with persistent AF despite a partial GP modification resulting from the pulmonary vein isolation.

AF Ablation in HD Patients. Introduction: It is not common for patients on chronic hemodialysis (HD) to undergo catheter ablation of atrial fibrillation (AF). We aimed to show the outcomes of AF ablation in the HD patients. Methods and Results: Thirty HD patients who underwent pulmonary vein (PV) isolation for drug refractory paroxysmal AF were retrospectively studied, and their AF recurrence free rate and frequency of periprocedural complications were compared to 60 age- and gender-matched control patients not requiring HD. A nonirrigated ablation catheter was used in both patient groups. During a mean follow-up period of 821 ± 218 days, 16 (54%) of the HD patients remained free from AF recurrence without any antiarrhythmic agents versus 47 (78%) of the control patients with an initial ablation (P = 0.013). A second ablation procedure was performed in 12 patients with an AF recurrence, and consequently 20 (67%) of the HD patients were in sinus rhythm compared to 53 (88%) of the controls during a follow-up duration of 747 ± 221 after the last ablation (P = 0.012). Bleeding from the venipuncture site requiring a prolonged hospital stay was identified in 2 HD patients and 1 control subject, while no life-threatening complications were observed in either patient group. Conclusion: Although the success rate of the PV isolation in HD patients was far from satisfactory, it may be considered as one of the therapeutic options for them. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1289-1294, December 2012)

Atrioventricular (AV) conduction disturbances have often been considered as an etiology of prolonged pauses during atrial fibrillation (AF). We aimed to test whether there was a significant difference in the AV conduction properties between patients with and without clinically significant pauses who underwent ablation of longstanding persistent AF. Ninety-nine patients undergoing ablation of longstanding persistent AF were divided into three groups according to the extent of pauses documented on the ambulatory electrocardiogram during AF; patients without pauses (n = 25), with pauses of

Aims We aimed to determine how many electrical cardioversions (ECs) should be applied to treat repetitive persistent recurrences of atrial fibrillation (AF) following ablation of persistent AF within the early post-procedural period. Methods and results A total of 40 patients with >1 episode of recurrent AF in the form of persistent atrial arrhythmias within 3 months following the ablation were recruited from 108 patients who underwent ablation for persistent or long-standing persistent AF. Electrical cardioversions were applied up to six times, if necessary, to restore sinus rhythm at clinical visits at 2-week intervals until 3 months after the ablation. Fourteen (35%) ablation failures defined as recurrences of AF identified from the 3rd month after the ablation procedure were finally diagnosed during the follow-up period (14 ± 4 month). The patients with an ablation failure more frequently required ECs than those without (3.7 ± 0.3 vs. 1.2 ± 0.2 times; P < 0.0001). A receiver-operating characteristic curve identified a number of ECs of ≥3 as the optimal cut-off value for predicting an ablation failure (area under the curve 0.91; sensitivity, 86%, and specificity, 96%; P = 0.0007). In the multivariate logistic regression analysis, a number of ECs of ≥3 was the only independent predictor of an ablation failure (odds ratio, 11.32; 95% confidence interval, 3.83–58.22; P = 0.0019). Conclusion It was difficult to maintain sinus rhythm in patients with persistent AF who required several ECs for recurrences of AF within the early post-ablation period.

Summary Purpose We evaluated whether time-dependent procedural improvement was independently associated with reduction in atrial fibrillation (AF) recurrences or periprocedural complications in patients who underwent catheter ablation for AF at a single medium-volume center. Methods A total of 208 consecutive patients who underwent AF ablation from June 2006 to June 2009 were enrolled. All procedures were performed by an experienced operator, and the ablation protocol, devices, and equipment remained unchanged throughout the study period. The study period was divided into quarters (1–4 Q) to include the same number of patients within each quarter. The incidence of AF recurrences or periprocedural complications requiring a prolonged hospital stay or surgical intervention was retrospectively compared across the quarters. Results During follow-up (15 ± 3 months), we observed 26 (13%) AF recurrences (27% in 1Q, 15% in 2Q, 6% in 3Q, 2% in 4Q; 1Q vs. 3Q, p = 0.0035; 1Q vs. 4Q, p = 0.0003; 2Q vs. 4Q, p = 0.013) and 15 (7%) periprocedural complications (12% in 1Q, 8% in 2Q, 6% in 3Q, 4% in 4Q), both of which declined progressively over time. Multiple logistic regression analysis revealed that 1Q, but not any other patient background parameters, was an independent predictor of the incidence of AF recurrence or periprocedural complications (odds ratio, 2.45; 95% confidence interval, 1.19–5.20; p = 0.015). Conclusions The time period when the procedure was performed significantly influenced the AF ablation outcome, indicating that operators in medium-volume centers should be committed to providing gratifying outcomes particularly early in the institutional experience with AF ablation.

We hypothesized that excessive suppression of platelet function due to antiplatelet therapy can increase the incidence of bleeding complications. The aim of the present study was to find whether we could predict bleeding events by measuring platelet function.We enrolled 743 subjects whose platelet function was measured using a whole blood aggregometer based on a screen filtration pressure method. Of these subjects, 551 (74.2%) were treated with some type of antiplatelet agent. The endpoints were bleeding or ischemic events requiring hospitalization or extension of hospital stay. We prospectively compared the platelet function of subjects with and without bleeding or ischemic events.During 556 ± 207 days of follow-up, 52 (7.0%) bleeding events and 20 (2.7%) ischemic events were observed. Kaplan-Meier analysis using the log-rank test revealed that an aggregation rate of20% induced by 8 µ M adenosine diphosphate (ADP) was significantly associated with a greater number of bleeding events (11.9% vs. 5.2%; p = 0.0007). Cox proportional hazards model showed that age75 years (hazard ratio [HR], 1.78; 95% confidence interval [CI], 1.03-3.10; p = 0.039), estimated glomerular filtration rate60 ml/min/1.73 m(2) (HR, 1.82; 95% CI, 1.06-3.18; p = 0.031) and aggregation rate20% induced by 8 µ M ADP (HR, 2.18; 95% CI, 1.24-3.80; p = 0.0071) were independent predictors of bleeding events.Low platelet function demonstrated using a whole blood aggregometer was an independent predictor of bleeding complications.

Background: Adequate catheter-to-myocardial contact force (CF) and catheter stability are important to create transmural lesions during catheter ablation of atrial fibrillation (AF). It is known that there are anatomical variations in left atrium (LA) and it is related to the outcome after the ablation. We tested any relationship between the CF and LA anatomical variations. Methods: Consecutive patients undergoing radiofrequency-based extensive encircling pulmonary vein (PV) isolation for the treatment of paroxysmal AF were dichotomized according to the LA anatomical variations; patients who had a PV-bifurcation region of LA ridge that was steep enough to enable a stable catheter-tip contact or a left common PV (group 1, the red arrows in Figure 1), or those who had neither (group 2, the blue arrows in Figure 1). The blinded operators carried out the procedure with the use of CARTO system, and the following VisiTag™ module setting was applied; a minimum time spent in an area of 5 seconds, a maximum distance the catheter has moved of 4mm, a force over time of 25%, and a minimum force of 10g. Low-CF tags was defined as ablation tags on CARTO map located at anterior aspect of left PVs that did not fulfill the pre-determined VisiTag™ criteria. The endpoints were the number of low-CF tags and freedom from AF 1 year after the ablation. Results: Patients in group 1 (n=31) had a smaller number of low-CF tags than those in group 2 (n=55, 2.8±2.1 vs. 5.9±3.8; p=0.013). Freedom from AF was more common in group 1 compared to group 2 (80.6% vs. 60%; p=0.04), and was independently associated with the number of low-CF of Conclusions: Contact of the catheter-tip with the tissue may predict outcome after AF ablation, and it may depend on LA anatomical variations.

The common SCN5A polymorphism, H558R (c.1673A>G,rs1805124), has been reported to be a genetic modulator of Brugada syndrome (BrS) carrying a SCN5A mutation. H558R has been known to improve the sodium channel activity in mutated channels by restoring the abnormal channel gating kinetics or membrane trafficking. The mechanisms by which H558R rescues the SCN5A mutations remain incompletely defined. We investigated the possible mechanism of why H558R modifies the effects brought by an SCN5A mutation. We investigated rs1805124 in 95 BrS patients (91 males, mean age 42 ± 14 years) and 1,875 normal controls (1546 male, mean age 54±18 years). We obtained the right atrial sections during aortic aneurysm operations from 21 patients and rs1805124 was also genotyped in them. Using cDNA of these patients, we examined the expression level of SCN5A by real time RT-PCR and whether splicing of exon 9 to exon 10 in SCN5A was correct by RT-PCR.and evaluate the difference between the genotypes of rs1805124. Additionally, we analyzed the expression ratio of the A allele and G allele separately by specific probes in heterozygous patients. H558R was less frequent in patients with BrS than in normal controls (4.7% vs. 10.3%, P = 0.01). We found strong Linkage disequibrium (LD) in c1141-3C>A (Intron 9) and H558R (r2=0.946). The genotype distribution of the rs1805124 of AA, AG, and GG genotypes in the 21 patients were 13 (61.9 %), 8 (38.1 %), and 0 (0%), respectively. The expression level of SCN5A was similar in the patients with and without H558R. There were not any splicing abnormalities of SCN5A despite of H558R existence. The A allele expression level was mean 1.38 fold higher than that for the G allele (P=0.004). The result suggested that the mutation effect was relieved if the heterozygous mutation rode on the risk allele G. We may have elucidated one reason why H558R modifies the effects brought on by SCN5A mutations.

Objective: Little is known about the clinical features in patients with cardiac sarcoidosis who receive cardiac resynchronization therapy (CRT). We aimed to clarify the clinical response to CRT in patients with cardiac sarcoidosis. Methods: We compared the clinical data on CRT between heart failure patients with cardiac sarcoidosis and those with other etiologies at 3 cardiovascular centers. The primary endpoint was composite outcome of cardiovascular death or hospitalization from worsening heart failure within 5 years after the CRT. Results: The patients with cardiac sarcoidosis (N=18) were more likely than those without cardiac sarcoidosis (N=141) to be female (83.3% vs. 22.7%; P Conclusions: Outcomes after the CRT may be acceptable in patients with cardiac sarcoidosis. A poor left ventricular reverse remodeling and higher occurrence of ventricular arrhythmias may characterize them.

Background: Previous study showed that number of yellow plaque in a coronary artery was associated with future risk of acute coronary syndrome. However, impact of intrastent yellow plaque has not fully understood. Purpose: This study was investigated to assess the association of the grade of intrastent yellow plaque observed by coronary angioscopy at late phase after drug-eluting stents (DES) implantation and clinical outcome. Methods: This study consisted of 97 patients tread with DES implantation (39 patients with sirolimus-eluting stents ; 9 patients with paclitaxel-eluting stents; 24 patients with everolimus-eluting stents; 6 patients with zotalolimus-eluting stents; 19 patients with biolimus-eluting stents ). Coronary angioscopy was performed 8 months after DES implantation. The plaque color at stent segment was grade as 0 (white), 1 (light yellow), 2 (yellow), 3 (bright yellow). The maximum color grade of the plaques in stent segment was assessed. We divided these patients into 2 groups (53 patients with yellow plaque grade 2 or 3; 44 patients with yellow plaque grade 0 or 1). We evaluated the incidence of revascularization, such as percutaneous coronary intervention or coronary artery bypass graft. Results: Kaplan-Meier curves for 7-year Revascularization free rate are shown in Figure. Revascularization free rate was tend to be higher in patients with yellow grade 0/1 than those with yellow grade 2/3. Conclusion: The presence of intrastent yellow plaque at late phase after stent implantation might be associated with the future revascularization in coronary artery disease.

Aim: Risk stratification of ventricular fibrillation (VF) in Brugada syndrome remains controversial and it is difficult to describe using one parameter. We investigated whether we are able to assess VF risk using our non-invasive scoring method of each Brugada syndrome patients. Methods: We enrolled 46 patients with Brugada syndrome (45 men, average age 42 ± 3 years). Thirteen of the subjects had VF history or subsequent VF events (VF+) after implantable cardioverter defibrillator implantation. The frequency of Type1 Brugada ECG and positive TWA were significantly higher in VF+ patients than those without (Type 1 ECG 50% vs 4.8%, P=0.0003 and positive TWA 73.3% vs 6.7%, P Conclusions: The new scoring method using previous reported non-invasive risk factors of VF in Brugada syndrome is useful for assessing risk stratification in daily medical practice.

Left atrial (LA) remodeling progresses to electrical remodeling, contractile remodeling, and subsequently structural remodeling. Little is known about the relationship between LA electrical and anatomical remodeling and LA mechanical function.We aimed to clarify the relationship between LA mechanical function using 3-dimensional speckle-tracking echocardiography (3D-STE) and LA electrical remodeling using an electroanatomic mapping system (CARTO 3) and to estimate atrial fibrillation (AF) substrate in patients with paroxysmal AF (PAF).A total of 52 patients with PAF (41 (79%) men; mean age 61 ± 11 years) undergoing their initial pulmonary vein isolation (PVI) were examined. The standard deviation of the time to peak strain in each LA segment (%SD-TPS) was analyzed as an index of LA dyssynchrony using 3D-STE before PVI. Contact LA bipolar voltage and activation maps were constructed during sinus rhythm before PVI using CARTO 3. The LA total activation time was measured and low-voltage zones (LVZs) were determined with a local bipolar electrogram amplitude of0.5 mV. The patients were divided into those with an LVZ (LVZ group; n = 23) and those without an LVZ (non-LVZ group; n = 29).The %SD-TPS was significantly higher (14.1 ± 5.7 vs 8.0 ± 5.1; P=.0002) in the LVZ group than in the non-LVZ group and was an independent determinant of the LVZ (odds ratio 1.21; 95% confidence interval 1.04-1.49; P=.01). In addition, the LA total activation time was weakly correlated with the %SD-TPS.LA dyssynchrony and conduction delay exist in patients with PAF. The 3D-STE enabled noninvasive estimation of LA electrical remodeling and AF substrate.

It is uncertain whether rate or rhythm control is more favorable for patients experiencing tachycardia-induced cardiomyopathy (TIC) secondary to rapid atrial fibrillation (AF).We compared the electrophysiological and hemodynamic properties and outcome after AF ablation in 20 patients with a history of decompensated TIC who maintained sinus rhythm or had paroxysmal AF (group 1), 32 with a history of decompensated TIC who had persistent or longstanding persistent AF (group 2), 377 without TIC who had paroxysmal AF (group 3), and 225 without TIC who had persistent or longstanding persistent AF (group 4). The corrected sinus node recovery time was more prolonged in group 2 than in groups 1, 3, or 4 (1,066 ± 946 vs. 416 ± 188, 450 ± 322 and 590 ± 329 milliseconds; P0.001, respectively). The mean left atrial pressure in group 2 was greater than that in groups 1, 3, or 4 (13.9 ± 6.5 vs. 7.5 ± 3.1, 8.2 ± 4.1 and 10.8 ± 4.2 mmHg; P0.001, respectively). The left ventricular ejection fraction assessed after the recovery from the decompensation was more decreased in group 2 than in group 1; however, it almost returned to normal if sinus rhythm was maintained after the AF ablation in group 2. The presence of a history of TIC did not predict an AF recurrence after the ablation.Heart rate control during AF without sinus conversion may result in an incomplete cure of TIC, suggesting the advantages of rhythm control with ablation in patients with TIC.

T-wave alternans (TWA) is an indicator of vulnerability to ventricular arrhythmias and is useful for predicting sudden cardiac death (SCD) in patients with various structural heart diseases. We evaluated whether high levels of time-domain TWA on ambulatory ECG (AECG) are associated with a history of ventricular fibrillation (VF) in Brugada syndrome (BrS) patients.We examined the associations among VF history, family history of SCD, spontaneous type 1 electrocardiogram (ECG), late potentials, VF induction by programmed electrical stimulation, and TWA in 45 BrS patients (44 males; mean age, 45 ± 15 years). TWA analyzed from 24-h AECG recordings using the modified moving average method was positive in 13 of 43 patients (30%). Patients with a history of VF had a significantly higher incidence of a positive TWA test (82% vs. 13%; P0.001) and spontaneous type 1 ECG (92% vs. 38%; P = 0.007) than those without VF history. Multivariate analysis indicated that positive TWA (OR 7.217; 95% CI 2.503-35.504; P = 0.002) and spontaneous type 1 ECG (OR 5.530; 95% CI 1.651-34.337; P = 0.020) were closely associated with VF history. Spontaneous type 1 ECG had high sensitivity (92%) but low specificity (63%). Positive TWA was a reliable marker with high sensitivity and specificity (82% and 88%, respectively).Elevated time-domain TWA on AECG confirms arrhythmia risk in symptomatic BrS patients without the need for provocative stimuli.

Although it is relatively rare, there are some patients with persistent or longstanding (LS) persistent atrial fibrillation (AF) who develop recurrences of AF with a paroxysmal form after pulmonary vein (PV) isolation [1]. Since there is no consensus on how to treat those patients, we tested what the results would be if they underwent a repeat ablation procedure. Consecutive patients were eligible for inclusion if they had any symptoms resulting from recurrent paroxysmal or persistent AF after PV isolation for the initial treatment of persistent or LS persistent AF, and then underwent a second ablation procedure. The types of AF were defined according to the current guidelines [2]. Written informed consent was obtained from all patients, and the study protocol was approved by the research committee of the institution. A double lasso guided extensive PV isolation with a cavotricuspid isthmus (CTI) ablation was performed in each patient as an initial ablation procedure. The details of the procedurewere described in our previous work [3]. In the second procedure, if any electrical reconnection was seen in the PVs or CTI, re-ablation was carried out in the samemanner as in the initial session. In principle, a roof line and anterior line [2] were additionally created if the patients had one or no reconnected PV. Finally, the superior vena cava was isolated circumferentially in all patients. The antiarrhythmic drugs withdrawn before the ablation were resumed the evening of the procedure in all patients. We scheduled to follow them up 3, 9, 12, and finally 24 months after the procedure to screen for any AF recurrences defined based on the current guidelines [2]. The end point was an AF recurrence occurring after the 2nd session in patients with a paroxysmal form of AF recurrence and those with a persistent form of AF recurrence after the 1st session.

Anticoagulation with novel oral anticoagulants (NOACs) for patients undergoing catheter ablation of atrial fibrillation (AF) has rapidly spread all over the world. Nevertheless, there is a lack of information on how to use the NOACs during the periprocedural period. In this review, we introduced the current trend in the way to use the NOACs during the periprocedural period of the AF ablation, and discussed its problems and future challenges.