Comparison of atrial arrhythmia recurrence after persistent atrial fibrillation ablation between patients with or without tachycardia-induced cardiomyopathy.

BACKGROUND: The presence of heart failure (HF) has been associated with poorer outcomes in patients undergoing catheter ablation (CA) for atrial fibrillation (AF). However, the effectiveness of CA amongst the subset of patients with tachycardia-induced cardiomyopathy (TIC) remains poorly defined. METHODS AND RESULTS: In a retrospective analysis we compared outcomes of first-time CA for persistent AF in a cohort of patients with previously diagnosed TIC (n = 45; age 58 ± 8 years; 91% male) to those with structurally normal hearts (non-TIC; n = 440; age 55 ± 9 years; 95% male). TIC was defined as an impaired ventricular function (left ventricular ejection function [LVEF] <50%), which was reversed after the treatment of HF. We compared atrial arrhythmias (AAs) recurrence after the CA in the TIC and non-TIC cohorts. In the TIC group, LVEF improved from 35.8% ± 8.1% to 57.5% ± 8.3% after treatment of HF. During 3.3 ± 1.5 years follow-up, AAs-free survival after CA was significantly higher in the TIC group as compared with the non-TIC group (69% vs 42%; P = .001), despite a comparable CA strategy between the two groups. In multivariable analysis, absence of HF with TIC, longer AF duration, and complex fractionated atrial electrogram ablation were independent predictors of arrhythmia recurrence (OR, 1.02; 95% CI, 1.01-1.03; P < .01; OR, 0.40; 95% CI, 0.20-0.79; P < .01 and OR, 2.29; 95%CI; 1.27-4.11; P < .01, respectively). In addition, the outcome after the last procedure was superior in the TIC cohort (89% vs 72%; P = .03) with fewer CA procedures as compared with the non-TIC cohort (1.3 ± 0.5 vs 1.5 ± 0.7; P = .01). CONCLUSIONS: Persistent patients with AF with TIC have a more favorable outcome after the CA as compared with those without.

Atrial fibrillation diagnosed by a medical checkup is associated with a poor outcome of catheter ablation.

Atrial fibrillation (AF), especially asymptomatic cases, is often detected by medical checkups. We investigated the outcome of AF ablation in cases detected by medical checkups. We reviewed the data of 735 patients with AF (56 ± 10 years, paroxysmal: 441 patients) who underwent initial catheter ablation. All patients were divided into two groups based on their AF being diagnosed either by a medical checkup (group M) or not (group NM). AF was diagnosed by medical checkups in 263 (36%) patients. In Group M, the age was younger, time from the diagnosis to ablation shorter, left atrium dimension larger, and left ventricular ejection fraction lower than in Group NM. Male gender, persistent AF, and asymptomatic AF were more frequently seen in Group M than in Group NM. A mean of 13 ± 11 months after the initial ablation procedure, AF recurrence was more frequently observed in group M compared to group NM (P = 0.018). While the AF recurrence rate was similar in both groups in persistent AF patients (P = 0.87), it was more frequently observed in Group M than in Group NM in paroxysmal AF patients (P = 0.005). AF diagnosed by medical checkups was often associated with a worse outcome of catheter ablation, especially in paroxysmal AF patients.

Influence of the concomitant use of heparin on the effects of warfarin during catheter ablation for atrial fibrillation.

Warfarin is widely used to perform catheter ablation for atrial fibrillation (AF). Heparin is usually administered during this procedure to prevent thromboembolic events, while protamine is used to reduce the incidence of bleeding complications. The purpose of this study was to investigate the influence of heparin and protamine administration on the effects of warfarin and its safety. The subjects included 226 AF patients (206 males, 54.9 ± 9.1 years, paroxysmal/persistent AF: 118/108) undergoing AF ablation with the discontinuation of warfarin administration over 2 days. Heparin was administered to achieve an activated clotting time (ACT) above 300 s during the procedure. Several parameters of the coagulation status, including the prothrombin time international normalized ratio (PT-INR) and ACT values, measured immediately before and after protamine infusion were compared. The mean value of PT-INR prior to ablation was 1.9 ± 0.6. At the end of the procedure, the mean ACT and PT-INR values were 348.0 ± 52.9 and 2.9 ± 0.7, respectively. Following the infusion of 30 mg of protamine, both the ACT and PT-INR values significantly decreased, to 159.6 ± 31.0 (p < 0.0001) and 1.6 ± 0.3 (p < 0.0001), respectively. No cases of symptomatic cerebral infarction were observed, although femoral hematomas developed in 17 (7.5 %) of the patients without further consequence. The concomitant use of heparin augments the effect of warfarin. Meanwhile, protamine administration immediately reverses both the ACT and PT-INR, indicating the applicability of protamine for AF ablation in patients under the mixed administration of heparin and warfarin.

Filling defects of the left atrial appendage on multidetector computed tomography: their disappearance following catheter ablation of atrial fibrillation and the detection of LAA thrombi by MDCT.

Filling defects of the left atrial appendage (LAA) on multidetector computed tomography (MDCT) are known to occur, not only due to LAA thrombi formation, but also due to the disturbance of blood flow in the LAA of patients with atrial fibrillation (AF). The purpose of this study was to evaluate the impact of the maintenance of sinus rhythm via ablation on the incidence of LAA filling defects on MDCT in patients with AF. A total of 459 consecutive patients were included in the present study. Prior to ablation, MDCT and transesophageal echocardiography (TEE) were performed. AF ablation was performed in patients without LAA thrombi confirmed on TEE. The LAA filling defects were evaluated on MDCT at 3 months after ablation. LAA filling defects were detected on MDCT in 51 patients (11.1 %), among whom the absence of LAA thrombi was confirmed in 42 patients using TEE. The LAA Doppler velocity in patients with LAA filling defects was lower than that of patients without filling defects (0.61 ± 0.19 vs. 0.47 ± 0.21 m/s; P < 0.0001). The sensitivity, specificity and negative predictive value of MDCT in the detection of thrombi were 100, 91 and 100 %, respectively. No LAA filling defects were observed on MDCT at 3 months after ablation in any of the patients, including the patients in whom filling defects were noted prior to the procedure. MDCT is useful for evaluating the presence of LAA thrombi and the blood flow of the LAA. The catheter ablation of AF not only suppresses AF, but also eliminates LAA filling defect on MDCT suggesting the improvement of LAA blood flow.

The role of successful catheter ablation in patients with paroxysmal atrial fibrillation and prolonged sinus pauses: outcome during a 5-year follow-up.

AIMS: Although patients with paroxysmal atrial fibrillation (AF) and prolonged sinus pauses [tachycardia-bradycardia syndrome (TBS)] are generally treated by permanent pacemaker, catheter ablation has been reported to be a curative therapy for TBS without pacemaker implantation. The purpose of this study was to define the potential role of successful ablation in patients with TBS. METHODS AND RESULTS: Of 280 paroxysmal AF patients undergoing ablation, 37 TBS patients with both AF and symptomatic sinus pauses (age: 62 ± 8 years; mean maximum pauses: 6 ± 2 s) were analysed. During the 5.8 ± 1.2 years (range: 5-8.7 years) follow-up, both tachyarrhythmia and bradycardia were eliminated by a single procedure in 19 of 37 (51%) patients. Repeat procedures were performed in 14 of 18 patients with tachyarrhythmia recurrence (second: 12 and third: 2 patients). During the repeat procedure, 79% (45 of 57) of previously isolated pulmonary veins (PVs) were reconnected to the left atrium. Pulmonary vein tachycardia initiating the AF was found in 46% (17 of 37) and 43% (6 of 14) of patients during the initial and second procedure, respectively. Finally, 32 (86%) patients remained free from AF after the last procedure. Three patients (8%) required pacemaker implantation, one for the gradual progression of sinus dysfunction during a period of 6.5 years and the others for recurrence of TBS 3.5 and 5.5 years after ablation, respectively. CONCLUSION: Catheter ablation can eliminate both AF and prolonged sinus pauses in the majority of TBS patients. Nevertheless, such patients should be continuously followed-up, because gradual progression of sinus node dysfunction can occur after a long period of time.

Association between the early repolarization pattern and nocturnal suicide attempts.

AIM: Numerous recent reports have highlighted the association between mental disorders and electrocardiographic findings. The early repolarization pattern (ERP) on electrocardiogram has been linked with a history of suicide attempts and attention deficit hyperactivity disorder, and associations with impulsivity have also been reported. It is known that suicidal intent is more common at night. Patients who have a mental disorder and ERP may have a higher likelihood of impulsivity, potentially increasing the risk of suicide at night. METHODS: The subjects were 43 patients with a history of suicide attempts who had undergone electrocardiographic examination at Jikei University School of Medicine Kashiwa Hospital and received intervention from our department. Due to the diurnal variation in electrocardiographic findings, only patients who underwent the examination during the daytime were included. Patients' clinical backgrounds were compared according to the presence or absence of ERP, and the association between nocturnal suicide attempts and ERP was examined using multivariate analysis. RESULTS: The frequency of nocturnal suicidal behavior was 76.2% in patients with ERP and 31.8% in those without ERP, but the difference was not significant after Bonferroni correction. In the multivariate analysis, there was a significant association of ERP with nocturnal suicide attempts (p = 0.018). CONCLUSION: The finding of an association between ERP and nocturnal suicide attempts indicates that ERP is a biological indicator that can predict nocturnal suicide attempts.

Improvement of atrioventricular conduction following catheter ablation of atrioventricular nodal reentry tachycardia in a patient with a prolonged PR interval.

We herein present the case of a 60-year-old male with narrow QRS tachycardia who had a remarkable PR prolongation during sinus rhythm. The tachycardia was diagnosed as a slow-fast atrioventricular nodal reentry tachycardia. Slow pathway ablation was performed after the confirmation of the presence of an antegrade fast pathway. Following the elimination of the slow pathway, the PR and atrio-His intervals became shortened from 470 and 420 to 170 and 120 ms, respectively. Moreover, the improvement of atrioventricular conduction after the slow pathway ablation lasted for at least 34 months.

[Nonspecific reacting materials that interferes tacrolimus assay by ACMIA].

We report two cases of falsely elevated levels of Tacrolimus (TAC) measured by affinity column mediated immunoassay (ACMIA). Potential reasons for this are herein explored. Patient 1, a post-renal transplantation patient, was treated by TAC, while patient 2, a patient with rheumatoid arthritis, was not. TAC levels measured by ACMIA of patients 1 and 2 were greater than 40 and 20 ng/ml, respectively. In patient 2, rheumatoid factor (RF) levels were constantly higher than 1,000 IU/ml, and levels of TAC were shown to be correlated with RF. Results of immunoglobulin adsorption tests and gel filtration suggested that the false positivities for TCA were induced by IgG of patient 1 and IgM of patient 2. After the addition of anti-TAC antibody, levels of TAC decreased to an undetectable range in both cases. TAC levels also became undetectable after the addition of MAK33-Framework IEP in patient 1 and IIR in patient 2. In patient 2, the addition of HBR-1 and MAK absorbent prevented the false positive phenomenon. In both cases, human anti mouse antibodies (HAMAs) reacted to anti-TAC mouse monoclonal antibodies within the reagent and produced falsely elevated results. These results were inhibited by MAK33-Framework IEP binding to the hyper-variable region of immunoglobulin; therefore, the causative agent of this phenomenon in patient 1 was likely an anti-idiotype antibody against the mouse monoclonal anti-TAC antibody used in the assay. Furthermore, a close relationship between measured levels of TAC and RF, along with the finding that the addition of HBR-1 and IRR prevents false positive results, suggests that RF produced false positive results through IgM-HAMA activity in patient 2. These data indicate that false positive results of TAC can be due to the presence of HAMAs with different specificities.

Substrate modification by pulmonary vein isolation and left atrial linear ablation in patients with persistent atrial fibrillation: its impact on complex-fractionated atrial electrograms.

UNLABELLED: PV and Linear Ablation for CFAEs. INTRODUCTION: Linear ablations in the left atrium (LA), in addition to pulmonary vein (PV) isolation, have been demonstrated to be an effective ablation strategy in patients with persistent atrial fibrillation (PsAF). This study investigated the impact of LA linear ablation on the complex-fractionated atrial electrograms (CFAEs) of PsAF patients. METHODS AND RESULTS: A total of 40 consecutive PsAF patients (age: 54 ± 10 years, 39 males) who underwent catheter ablation were enrolled in this study. Linear ablation of both roofline between the right and left superior PVs and the mitral isthmus line joining from the mitral annulus to the left inferior PV were performed following PV isolation during AF. High-density automated CFAE mapping was performed using the NAVX, and maps were obtained 3 times during the procedure (prior to ablation, after PV isolation, and after linear ablations) and were compared. PsAF was terminated by ablation in 13 of 40 patients. The mean total LA surface area and baseline CFAEs area were 120.8 ± 23.6 and 88.0 ± 23.5 cm(2) (74.2%), respectively. After PV isolation and linear ablations in the LA, the area of CFAEs area was reduced to 71.6 ± 22.6 cm(2) (58.7%) (P < 0.001) and 44.9 ± 23.0 cm(2) (39.2%) (P < 0.001), respectively. The LA linear ablations resulted in a significant reduction of the CFAEs area percentage in the region remote from ablation sites (from 56.3 ± 20.6 cm(2) (59.6%) to 40.4 ± 16.5 cm(2) (42.9%), P < 0.0001). CONCLUSION: Both PV isolation and LA linear ablations diminished the CFAEs in PsAF patients, suggesting substrate modification by PV and linear ablations. (J Cardiovasc Electrophysiol, Vol. 23, pp. 962-970, September 2012).

Identification of a conduction gap of the mitral isthmus by using a novel high-density mapping catheter.

Peri-mitral atrial flutter, which is a type of macroreentrant atrial tachycardia circulating around the mitral annulus, was terminated with the guidance of the high-density mapping catheter. A 72-year-old woman with atrial fibrillation and atrial tachycardia presented with symptoms of congestive heart failure. The recurrent peri-mitral atrial flutter following the initial catheter ablation for atrial tachycardia and atrial fibrillation was terminated by radiofrequency application on the gap that was identified using a novel high-density mapping catheter.

Real-time dominant frequency analysis of the pulmonary vein in patients with paroxysmal atrial fibrillation.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) can be treated with pulmonary vein isolation (PVI). A spectral analysis can identify sites of high-frequency activity during atrial fibrillation (AF). We investigated the role of the PVs on AF perpetuation by dominant frequency (DF) analysis. METHODS: Thirty-one consecutive patients with PAF who underwent PVI were included in the prospective study. DF was calculated in each of the PVs, 16, five, and five sites in the left atrium, the coronary sinus, and the right atrium, respectively. In patients presenting sinus rhythm at the baseline, AF was induced by pacing. The PVs were then divided into two groups; PVs demonstrated the highest DF (HDF-PV) and others. RESULTS: One patient was excluded from the analysis because sustained AF could not be induced. AF was terminated in 43.3% (13/30) of patients during ablation. Of 92 PVs isolated during AF, 30 and 62 PVs were classified into the HDF-PV and others, respectively. PAF was more frequently terminated by the HDF-PV isolation compared to the others (33.3% [10/30] vs 4.8% [3/62], P = 0.0004). Interestingly, nine of the 30 HDF-PVs showing the highest DF among all 30 regions, including extra PVs, led to AF termination in 88.9% (eight out of nine) of cases. Moreover, the HDF-PVs isolation resulted in a greater AF cycle length prolongation than the other PVs isolation (12.1±5.0 vs 2.7±7.6 ms, P = 0.007). CONCLUSION: Termination of PAF was more frequently observed during ablation of the PVs with the highest DF. The PV showing high DF played an important role in the maintenance of PAF.

Relationship between the early repolarization pattern and a history of suicide attempts among drug-free psychiatric patients.

AIM: Suicide attempts are an important severe psychiatric symptom and a clear outcome for mental disorders. Although the relationship between the early repolarization pattern in electrocardiogram and psychiatric disorders has recently been reported, these reports have not been able to exclude the influence of psychiatric drugs. This study aimed to investigate the relationship between the early repolarization pattern and a history of suicide attempts among patients not receiving psychiatric medication. METHODS: A total of 71 patients with a history of suicide attempts were investigated, 38 of whom were analyzed for this study. We compared the frequency of the early repolarization pattern between a suicide attempt group and a control group. Then, we investigated the association between the early repolarization pattern and the suicide attempt group by logistic regression analysis, including electrocardiographic findings associated with psychiatric disorders. RESULTS: The findings indicated that the frequency of the early repolarization pattern was significantly higher in the suicide attempt group (n = 20; 52.6%) than in the control group (n = 4; 10.5%) (P < 0.001), and the results of the logistic regression analysis indicated that the early repolarization pattern was associated with suicide attempts. CONCLUSIONS: These findings suggest that the early repolarization pattern is associated with a history of suicide attempts.

Dormant pulmonary vein conduction induced by adenosine in patients with atrial fibrillation who underwent catheter ablation.

BACKGROUND: intravenous administration of adenosine triphosphate (ATP) is used to induce transient pulmonary vein (PV) reconduction (dormant PV conduction) following PV isolation. This study investigated the detailed characteristics of dormant PV conduction in patients with atrial fibrillation (AF) who underwent catheter ablation. METHODS: two hundred sixty consecutive patients (235 men; mean age, 54 ± 10 years) who underwent catheter ablation of their AF were included in this study. ATP was injected following PV isolation to induce dormant PV conduction, which was then eliminated by radiofrequency application. RESULTS: dormant PV conduction was induced by ATP in 60.4% (157/260) of the patients and in 25.3% (258/1,021) of the isolated PVs. This transient PV reconduction was more frequently observed in the left superior PV in comparison with other PVs (P < .0001). There was no significant difference in the prevalence of the dormant PV conduction among patients with paroxysmal AF, persistent AF, and long-lasting AF (62%, 66%, and 48%, respectively; P = .13). During the follow-up period, repeat AF ablation was performed in 70 patients with recurrent AF. The dormant PV conduction was less frequently induced in the repeat procedure than in the initial procedure (60.4% vs 31.4%, P < .0001). CONCLUSIONS: dormant PV conduction was evenly induced among AF types. The repeat PV isolation led to the decrease in incidence of the ATP-induced acute transient pharmacological PV reconduction.

Completion of mitral isthmus ablation using a steerable sheath: prospective randomized comparison with a nonsteerable sheath.

BACKGROUND: Although mitral isthmus (MI) ablation in atrial fibrillation (AF) patients has been shown to be an effective ablative strategy, the establishment of the bidirectional conduction block of the MI is technically challenging. We investigated the usefulness of a steerable sheath for MI ablation in patients with persistent AF and its impact on the clinical outcome of persistent AF ablation. METHODS: A total of 80 consecutive patients undergoing MI ablation were randomized to 1 of the following 2 groups: group S (using a steerable long sheath) or group NS (using a nonsteerable long sheath). MI ablation was performed by using an open-irrigated ablation catheter with the guidance of a 3-dimensional mapping system. The endpoint of the MI ablation was the achievement of a bidirectional block. RESULTS: Bidirectional block through the MI was achieved in 87.5% (70/80) of patients with 14.0 ± 6.7 minutes of radiofrequency application. The bidirectional block was more frequently achieved in patients in group S compared to group NS (97.5% (39/40) vs 77.5% (31/40), P = 0.02). Additionally, epicardial ablation within the coronary sinus was less frequently required in group S compared to group NS (12.5% (5/40) vs 72.5% (29/40), P < 0.0001). Atrial tachycardia after the procedure more frequently occurred in the patients in whom MI block had not been achieved during the initial procedure (40.0% (4/10) vs 10.0% (7/70), P = 0.04). CONCLUSIONS: The MI block could be achieved in the majority of patients by using a steerable sheath. An incomplete MI block increased the risk of AT following persistent AF ablation.

Different strategies for performing pulmonary vein isolation in patients with pulmonary vein rhythm.

Pulmonary vein (PV) isolation was performed in atrial fibrillation (AF) patients whose cardiac rhythm was dominated by the ectopic beats originating from the PV. We herein report two cases with dominant PV ectopic rhythm that underwent catheter ablation for the treatment of paroxysmal AF. In one case, a permanent pacemaker implantation was required to treat a symptomatic long sinus pause after the isolation of all four PVs, while no AF was documented during the 5-year period after ablation. However, the isolation of all four PVs except for a PV with a dominant ectopic rhythm was performed in the other case. The latter case was free from both AF and symptomatic bradycardia following the procedure without the implantation of a pacemaker. Selective PV isolation therefore appears to be an effective therapy to both achieve the successful treatment of AF and to prevent the manifestation of sick sinus syndrome.

[Sequential changes in inflammatory and stress responses during 24-hour running].

Running for an extended period of time can cause severe stress on the body, subsequently damaging skeletal muscle and resulting in changes in blood components. However, few reports have examined vital responses during and after running. This study analyzed inflammatory responses during and after running and changes in stress responses as determined by serial changes in blood components. Venous blood was obtained before starting, 6 h after starting, 12 h after starting, and immediately after finishing 24 h of continuous running. Samples were analyzed for high-sensitivity C-reactive protein (hsCRP), pentraxin 3 (ptx3), white blood cells (WBC), myoglobin, creatine kinase (CK), and hormones. Diet and physical activity were standardized 24 h before and after running. Subjects comprised 16 men who agreed to participate in experimental running on November 8 and 9, 2008, at Tokyo Gakugei University. Mean running distance was 151.32 +/- 32.1 km (range, 83.6-210.0 km) in 24 h. A significant increase in hsCRP was seen from 12 h after starting to completion. Compared to hsCRP, ptx3 gradually increased from before starting to after completion, showing a significant difference between pre and post-run ptx3 levels. WBC count increased significantly until 6 h after starting. Neutrophils in leukocytosis increased significantly during the first 6 h. Eosinophils decreased significantly over the course of the 24 h. Cortisol increased, and testosterone decreased significantly from 6 h after starting. Dehydroepiandrosterone sulfate (DHEA-S), myoglobin, and CK increased over the course of the 24 h. Reactive oxygen metabolites (d-ROMs) changed within the normal range though there was a significant decrease, and biological anti-oxidant potential (BAP) stabilized. Active natural killer cells decreased significantly after 24 h running. Biopyrrin (BPn) increased significantly. Changes in stress oxide were small both during and after running, and adaptation for antioxidation was good. DHEAS, a biomarker of aging, was found to increase over the course of the 24 h, suggesting that controlling decreases in DHEA-S may be possible using exercise, particularly in males. The key finding was that DHEA S levels tended to increase with continuous aerobic exercise.

Melt-Spun Fibers from Bio-Based Polyester-Fiber Structure Development in High-Speed Melt Spinning of Poly(ethylene 2,5-furandicarboxylate) (PEF).

Poly(ethylene 2,5-furandicarboxylate) (PEF) is regarded as a bio-based alternative or complementary polyester for the widely used fossil resource-based polyester, poly(ethylene terephthalate) (PET). High-speed melt spinning of PEF of low and high molecular weight (L-PEF, H-PEF) was conducted, and the structure and properties of the resultant as-spun fibers were investigated. The occurrence of orientation-induced crystallization was confirmed for the H-PEF at the take-up velocity of 6.0 km/min, the highest speed for producing PET fibers in the industry. Molecular orientation and crystallinity of the as-spun fibers increased with the increase of take-up velocity, where the H-PEF fibers always showed a higher degree of structural development than the L-PEF fibers. The tensile modulus of the high-speed spun H-PEF fibers was relatively low at 5 GPa, whereas a sufficiently high tensile strength of approximately 500 MPa was measured. These values are adequately high for the application in the general semi-engineering fiber field.

Very long term outcome after linear versus electrogram guided ablation for persistent atrial fibrillation.

The optimal ablation strategy for persistent atrial fibrillation (PsAF) remains to be defined. We sought to compare very long-term outcomes between linear ablation and electrogram (EGM)-guided ablation for PsAF. In a retrospective analysis, long-term arrhythmia-free survival compared between two propensity-score matched cohorts, one with pulmonary vein isolation (PVI) and linear ablation including roof/mitral isthmus line (LINE-group, n = 52) and one with PVI and EGM-guided ablation (EGM-group; n = 52). Overall, 99% of patients underwent successful PVI. Complete block following linear ablation was achieved for 94% of roof lines and 81% of mitral lines (both lines blocked in 75%). AF termination by EGM-guided ablation was accomplished in 40% of patients. Non-PV foci were targeted in 7 (13%) in the LINE-group and 5 (10%) patients in the EGM-group (p = 0.76). During 100 ± 28 months of follow-up, linear ablation was associated with superior arrhythmia-free survival after the initial and last procedure (1.8 ± 0.9 procedures) compared with EGM-group (Logrank test: p = 0.0001 and p = 0.045, respectively). In multivariable analysis, longer AF duration and EGM-guided ablation remained as independent predictors of atrial arrhythmia recurrence. Linear ablation might be a more effective complementary technique to PVI than EGM-guided ablation for PsAF ablation.

Comparison of the clinical outcome after pulmonary vein isolation based on the appearance of adenosine-induced dormant pulmonary vein conduction.

BACKGROUND: The elimination of transient pulmonary vein (PV) reconduction (dormant PV conduction) revealed by adenosine in addition to PV isolation reduced the atrial fibrillation (AF) recurrence after catheter ablation. The dormant PV conduction is induced in approximately half of the AF patients that undergo PV isolation. The present study compared the clinical outcome of AF ablation in patients whose dormant PV conduction was eliminated by additional radiofrequency applications with the outcome in patients without dormant conduction. METHODS: A total of 233 consecutive patients (206 male, 54.2 +/- 10.1 years) that underwent AF ablation were included in the present study. Dormant PV conduction was induced by the administration of adenosine triphosphate after PV isolation and was eliminated by supplemental radiofrequency application. All patients were followed up for >12 months (mean 903 days) after the first ablation. RESULTS: Following PV isolation, dormant PV conduction was induced in 139 (59.7%) of 233 patients and was successfully eliminated in 98% (223/228) of those in the first ablation procedure. After the first procedure, 63.9% (149/233) of patients were free from AF recurrence events. The success rates of a single or final AF ablation in patients with the appearance of the dormant PV conduction were similar to those of patients without dormant conduction (P = .69 and P = .69, respectively). CONCLUSIONS: Dormant PV conduction was induced in over half of the patients with AF. After the elimination of adenosine triphosphate-induced reconnection, the clinical outcome of patients with the dormant PV conduction was equivalent to that of patients without conduction.

Prospective randomized comparison of a steerable versus a non-steerable sheath for typical atrial flutter ablation.

AIMS: Although cavotricuspid isthmus (CTI) ablation can cure typical atrial flutter (AFL), it might be difficult to achieve a bidirectional conduction block in the isthmus in some patients. We investigated the usefulness of a steerable sheath for CTI ablation in patients with typical AFL or atrial fibrillation. METHODS AND RESULTS: A total of 40 consecutive patients (36 males; mean age 55.2 +/- 10.0 years) undergoing CTI ablation were randomized to one of the following two groups: group S (using a steerable long sheath) or group NS (using a non-steerable long sheath). Ablation was performed using an 8 mm tip catheter. The anatomy of the CTI was evaluated by a dual-source computed tomography scan prior to the procedure. The procedural endpoint was the achievement of a bidirectional isthmus conduction block. Bidirectional block in the CTI was achieved in all patients with 485.3 +/- 416.4 s of radiofrequency (RF) application. The CTI anatomy, including the length, depth, and morphology, was similar between the two groups. The duration and total amount of RF energy delivery were significantly shorter and smaller in group S than in group NS (310 +/- 193 vs. 661 +/- 504 s, P = 0.006, and 12,197 +/- 7306 vs. 26,906 +/- 21,238 J, P = 0.006, respectively). CONCLUSION: The use of a steerable sheath reduced the time and amount of energy needed to achieve a bidirectional conduction block in the CTI. For patients in whom the establishment of a conduction block is difficult, a steerable sheath should be considered as a therapeutic option for typical AFL ablation.