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Background: Cardiac resynchronization therapy (CRT) improves cardiac function in patients with heart failure (HF) and dyssynchrony. However, a subset of responders develops a delayed decline in left ventricular (LV) systolic function, referred to as "delayed negative reverse remodeling (DNRR).", Objective: This study aimed to investigate the characteristics and prognosis of DNRR in CRT responders., Methods: A total of 203 patients undergoing CRT device implantation were analyzed. Among them, 100 responders were identified on the basis of a ≥5% absolute LV ejection fraction (LVEF) increase and a ≥15% relative LV end-systolic volume reduction at 6 months after CRT device implantation. DNRR was defined as a ≥5% absolute decrease in LVEF at 1 year after treatment response determination., Results: Of the responders, 22 (22.0%) exhibited DNRR, while 78 (78.0%) were classified as non-DNRR. The DNRR group showed a decline in LVEF from 41.2%±8.3% to 32.7%±9.6% (P<.001), while the non-DNRR group showed improvement from 42.8%±9.5% to 46.2%±10.5% (P<.001). Multivariate analysis identified LV end-systolic volume ≥ 100 mL (odds ratio [OR] 3.575; P=.041), paced QRS duration ≥ 150 ms (OR 4.427; P=.023), synchronized LV pacing rate < 85% (OR 5.753; P=.043) at 6 months after CRT device implantation, and intraventricular conduction disturbance (OR 5.593; P=.018) as independent predictors of DNRR. The DNRR group had significantly worse outcomes, including cardiac death and HF-related hospitalization, than did the non-DNRR group., Conclusion: Despite an initial response to CRT, a subset of patients with HF developed DNRR, which correlated with worse clinical outcomes. Identifying risk factors associated with DNRR may help optimize CRT management and improve long-term patient care., Competing Interests: Disclosures Dr Yanagisawa is affiliated with a department sponsored by Medtronic Japan. Other authors have no conflict of interest., (Copyright © 2025 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Venous vascular access complications are usually nonfatal but are the most common complications after transvenous catheter intervention. Vascular closure devices (VCDs) have recently become available for venous closure., Objective: This study aimed to evaluate the feasibility and efficacy of real-time ultrasound-guided venous closure with suture-mediated VCDs in patients who underwent catheter ablation., Methods: This single-center observational study enrolled 226 consecutive patients who underwent elective catheter ablation with femoral venipuncture. For hemostasis, vessel closure by VCD was performed with real-time ultrasound guidance after 2022 (n = 123) and without ultrasound guidance in 2021 (n = 103). The occurrence of venous access site-related complications (major, minor, or other) was compared., Results: The rate of device failure was significantly lower in patients with ultrasound guidance than in those without (1.6% vs 6.3%; P = .048). The occurrence of all venous access site-related complications was significantly lower in patients with ultrasound guidance than in those without (4.9% vs 18.4%; P = .001). Time to ambulation was shorter in patients with ultrasound guidance than in those without (2.0 ± 0.1 hours vs 2.2 ± 0.6 hours; P < .001)., Conclusion: Real-time ultrasound guidance can reduce device failure, access site-related complications, and time to ambulation in performing venous closure with a VCD., Competing Interests: Disclosures T.M. received lecture fees from Bayer Pharmaceutical Co, Ltd, Daiichi-Sankyo Co, Ltd, Dainippon Sumitomo Pharma Co, Ltd, Kowa Co, Ltd, MSD KK, Mitsubishi Tanabe Pharma Co, Nippon Boehringer Ingelheim Co, Ltd, Novartis Pharma KK, Pfizer Japan Inc, Sanofi-Aventis KK, and Takeda Pharmaceutical Co, Ltd; and received unrestricted research grant for the Department of Cardiology, Nagoya University Graduate School of Medicine from Astellas Pharma Inc, Daiichi-Sankyo Co, Ltd, Dainippon Sumitomo Pharma Co, Ltd, Kowa Co, Ltd, MSD KK, Mitsubishi Tanabe Pharma Co, Nippon Boehringer Ingelheim Co, Ltd, Novartis Pharma KK, Otsuka Pharma Ltd, Pfizer Japan Inc, Sanofi-Aventis KK, Takeda Pharmaceutical Co, Ltd, and Teijin Pharma Ltd. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The difference in coagulation state during the periprocedural period of atrial fibrillation (AF) ablation among patients with uninterrupted anticoagulation has not been fully elucidated., Objective: The purpose of this study was to compare periprocedural trends in coagulation markers among patients on uninterrupted anticoagulation for AF ablation., Methods: In total, 275 consecutive patients who underwent AF ablation were evaluated. These patients were divided according to the anticoagulant they received into the dabigatran group (DG) (n = 64); rivaroxaban group (RG) (n = 62); apixaban group (AG) (n = 60); edoxaban group (EG) (n = 59); and warfarin group (WG) (n = 30). The trends in coagulation markers and the rate of silent stroke (SS) confirmed by postoperative magnetic resonance imaging were evaluated., Results: The fibrin monomer complex (FMC) level on postoperative day 1 and the prothrombin fragment 1+2 (PF1+2) levels on the operative day and postoperative day 1 were higher in DG than in the other groups (P <.05, <.001, and <.001, respectively). The incidence of SS in DG (17%) was significantly higher than in RG (6%), AG (3%, EG (7%), or WG (4%) (P <.05). Dabigatran use independently predicted the occurrence of SS (odds ratio 4.12; 95% confidence interval 1.37-12.7; P <.05)., Conclusion: FMC and PF1+2 levels during the periprocedural period of AF ablation were higher in DG than in the other groups. Dabigatran use independently predicted the occurrence of SS., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The effect of uninterrupted oral anticoagulant use in patients with chronic kidney disease (CKD) during catheter ablation for atrial fibrillation (AF) is not fully understood., Objective: The present study aimed to evaluate the safety and efficacy of periprocedural uninterrupted direct oral anticoagulant (DOAC) use compared with those of uninterrupted warfarin use in patients undergoing catheter ablation for AF stratified by various renal function groups., Methods: A total of 2091 patients were retrospectively included in this study. The study population was divided into 4 groups: creatinine clearance level ≥80 mL/min (n = 1086), 50-79 mL/min (n = 774), 15-49 mL/min (n = 209), and <15 mL/min (n = 22). We investigated periprocedural complications and compared them between uninterrupted DOAC and warfarin groups., Results: There was no significant difference in thromboembolic events among the 4 groups (0.6%, 0.6%, 1.0%, and 0%, respectively; P = .792). However, major bleeding events (0.9%, 1.4%, 4.8%, and 4.5%; P < .001) and minor bleeding events (4.1%, 6.1%, 11.5%, and 13.6%; P < .001) primarily occurred in patients with CKD. The rate of periprocedural complications in the DOAC group was similar to that in the warfarin group for each renal function category. Adverse events did not differ after adjustment using propensity score-matched analysis. Multivariate analysis showed that lower body weight, antiplatelet drug use, initial ablation session, and CKD were independent predictors of adverse events., Conclusion: The periprocedural bleeding risk was increased in patients with CKD. Uninterrupted DOAC and warfarin administration during catheter ablation for AF in patients with CKD is feasible and effective., (Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Anti-Xa activity (AXA) in patients with nonvalvular atrial fibrillation (NVAF) and relationship to bleeding events remains unclear., Methods: We evaluated AXA in 94 patients at both trough and peak rivaroxaban concentrations. Rivaroxaban dosage was determined according to creatinine clearance (CrCl): 10 and 15mg once daily for patients with CrCl 15-49 and CrCl ≥50mL/min, respectively. AXA value distribution and its association with bleeding events were examined in enrolled subjects., Results: The mean peak AXA level was significantly higher than the mean trough level (1.98±0.81 vs. 0.16±0.15IU/mL; p<0.001). The peak AXA level significantly differed among patients with CrCl 15-29, 30-49, 50-79, and ≥80mL/min (2.51±0.83, 1.72±0.76, 2.05±0.82, and 1.66±0.51IU/mL, respectively; p=0.004). Major and non-major clinically relevant bleeding events occurred in 22 patients (23.4% and 14.6% per year, respectively). The mean peak AXA level was significantly higher in patients who experienced bleeding events than in those who did not (2.40±0.70 vs. 1.84±0.80IU/mL; p=0.001). A Cox multivariate analysis showed that the peak AXA level was independently related to the incidence of major and non-major clinically relevant bleeding events (p=0.012). Cumulative bleeding rates were significantly higher in patients with high peak AXA levels (p<0.001)., Conclusion: Peak AXA level was an independent predictor for bleeding events in Japanese NVAF patients receiving rivaroxaban., (Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Background: Atrial fibrillation (AF) and chronic kidney disease (CKD) are closely related. The present study aimed to evaluate the association between estimated glomerular filtration rate (eGFR) and outcomes after cryoballoon catheter ablation for AF., Methods: We included a total of 110 patients (64.0±10.1 years, 64% men) with paroxysmal AF who underwent second-generation cryoballoon catheter ablation in this study. Recurrence and change in renal function after ablation were assessed by stratification of eGFR sub-groups., Results: During a mean follow-up period of 9 months, 20 (18%) patients had AF recurrence after the first catheter ablation procedure. Multivariate Cox regression analysis showed that eGFR [hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.93-0.99, p=0.047], non-pulmonary vein (PV) ectopic beats at initial ablation (HR 2.92, 95% CI 1.03-8.27, p=0.043), and history of stroke (HR 7.47, 95% CI 2.30-24.2, p=0.001) were independent predictors of recurrence after the ablation. Among the CKD groups, recurrence was found in 7% (1/15), 12% (9/73), and 46% (10/22) of the eGFR ≥90mL/min/1.73m 2 , eGFR 60-89.9mL/min/1.73m 2 , and eGFR 30-59.9mL/min/1.73m 2 groups, respectively (p=0.001). Kaplan-Meier survival curves demonstrated that patients with eGFR 30-59.9mL/min/1.73m 2 had significantly worse prognosis than did the other groups (log-rank p<0.001). In addition, non-PV ectopic beats at initial ablation were detected in 7% (1/15), 14% (10/73), and 50% (11/22) of the patients among the three CKD groups, respectively (p<0.001). No patients developed contrast-induced nephropathy after the catheter ablation procedure., Conclusions: Low eGFR at baseline was an independent predictor of recurrence after cryoballoon ablation for paroxysmal AF. The presence of non-PV ectopic beats was significantly increased in patients with impaired renal function, which might be associated with a poor outcome., (Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Background: Close monitoring of intraoperative activated clotting time (ACT) is crucial to prevent complications during the periprocedural period of atrial fibrillation (AF) ablation. However, little is known about the ACT in patients receiving new oral anticoagulant agents (NOACs)., Objective: The purpose of this study was to evaluate change in the ACT among anticoagulant agents used during the periprocedural period of AF ablation., Methods: We examined 869 consecutive patients who underwent AF ablation between April 2012 and August 2014 and received NOACs (n = 499), including dabigatran, rivaroxaban, and apixaban, or warfarin (n = 370) for uninterrupted periprocedural anticoagulation. Changes in intraprocedural ACT were investigated among the anticoagulant agents. Furthermore, the incidence of periprocedural events was estimated., Results: The average time in minutes required for achieving a target ACT >300 seconds was significantly longer in the dabigatran group (DG) and apixaban group (AG) than in the warfarin group (WG) and rivaroxaban group (RG) (60 and 70 minutes vs 8 and 9 minutes, respectively; P < .001). In addition, the proportion of patients who achieved the target ACT after initial heparin bolus was significantly lower in the DG and AG than in the WG and RG (36% and 26% vs 84% and 78%, respectively; P < .001). Furthermore, the incidence of periprocedural complications was equivalent among the groups., Conclusion: The average time required to reach the target ACT was longer in the DG and AG than in the WG and RG., (Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Dipeptidyl peptidase-4 (DPP-4) inhibitors were recently reported to have cardioprotective effects via amelioration of ventricular function. However, the role of DPP-4 inhibition in atrial remodeling, especially of the arrhythmogenic substrate, remains unclear., Objective: We investigated the effects of a DPP-4 inhibitor, alogliptin, on atrial fibrillation (AF) in a rabbit model of heart failure caused by ventricular tachypacing (VTP)., Methods: Rabbits subjected to VTP at 380 bpm for 1 or 3 weeks, with or without alogliptin treatment, were assessed using echocardiography, electrophysiology, histology, and immunoblotting and compared with nonpaced animals., Results: VTP rabbits exhibited increased duration of atrial burst pacing-induced AF, whereas administration of alogliptin shortened this duration by 73%. The extent of atrial fibrosis after VTP was reduced by 39% in the alogliptin-treated group. VTP rabbits treated with alogliptin displayed a 1.6-fold increase in left atrial myocardial capillary density compared with nontreated rabbits. A 2-fold increase in endothelial nitric oxide synthase (eNOS) phosphorylation was observed in the left atrium of alogliptin-treated rabbits compared with nontreated rabbits. Moreover, a nitric oxide synthase inhibitor (N(ω)-nitro-l-arginine methyl ester) blocked the beneficial effects of alogliptin on AF duration, fibrosis, and capillary density., Conclusion: Alogliptin shortened the duration of AF caused by VTP-induced fibrotic atrial tissue by augmenting atrial angiogenesis and activating eNOS. Our findings suggest that DPP-4 inhibitors may be useful in the prevention of heart failure-induced AF., (Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Rivaroxaban is currently used to prevent stroke in patients with atrial fibrillation. Measuring coagulation function may help clinicians to understand the effects of this drug and the associated risk of bleeding., Methods and Results: Rivaroxaban was given to 136 patients with non-valvular atrial fibrillation. Mean age was 74.5±9.0 years (men: 63.2%) and mean CHADS2 score (±SD) was 1.8±1.2. Prothrombin times (PTs) and plasma soluble fibrin (SF) levels were examined in 84 out of 136 patients at baseline and at least 2 weeks thereafter. In 48 patients we were able to collect blood at exact times, namely just before and 3h after rivaroxaban administration, corresponding to the trough and peak concentrations. Mean peak PT in 48 patients was 17.1±3.6s and median peak SF level was 1.46μg/mL. Multiple regression analysis showed that female sex, high brain natriuretic peptide, and high dose were independent factors prolonging the peak PT. Patients with peak PTs ≥20s experienced significantly more bleeding events. Among 29 of 46 patients newly treated with rivaroxaban without any previous anticoagulant, we examined coagulation function at the exact trough and peak times. In 29 patients, peak PT was significantly more prolonged than the baseline or trough PT (p<0.001 for both), whereas trough PT was comparable to the baseline PT. In contrast, both trough and peak SF levels in these newly treated patients were significantly reduced than at baseline (p=0.003 and p<0.001, respectively)., Conclusions: In Japanese patients with non-valvular atrial fibrillation receiving rivaroxaban, a prolonged peak PT (≥20s) could indicate increased risk of bleeding, and both trough and peak SF levels were reduced relative to baseline. PT and SF are both valuable measures of coagulation status in patients receiving rivaroxaban, regardless of prior anticoagulant history., (Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Aims: MicroRNAs (miRNAs) are small non-coding RNAs discovered as potential new gene regulators. Their roles in the development of chronic heart failure (CHF), however, are largely unknown. Reduced catecholamine sensitivity is an early step of CHF. We examined whether altered expression of miRNAs was related to reduced catecholamine sensitivity in patients with CHF., Methods and Results: Maximum first derivative of left ventricular pressure (LV dP/dt(max)) at baseline and during infusion of dobutamine (10 μg kg(-1)min(-1)) were determined in 14 asymptomatic or mildly symptomatic (New York Heart Association class I or II) patients with idiopathic dilated cardiomyopathy (DCM). We performed microarray analysis for a total of 485 miRNAs using endomyocardial biopsy specimens from these 14 patients. Patients were classified into 2 groups based on a percent increase in LV dP/dt(max) by dobutamine infusion (ΔLV dP/dt(max)). These are Group I (n=7) with ΔLV dP/dt(max)>90%, and Group II (n=7) with ΔLV dP/dt(max)<90%. Out of 485 miRNAs, 32 were differentially expressed in the myocardium with reduced catecholamine sensitivity. Among those, four miRNAs were decreased and one miRNA was increased in the Group II compared to the Group I (p<0.01). LVEF measured by left ventriculography at baseline did not differ between the 2 groups. Also there were no differences in plasma norepinephrine levels between the 2 groups., Conclusions: Altered expression of several miRNAs was related to the reduced catecholamine sensitivity in mildly symptomatic patients with DCM. These findings shed light on the potential of miRNAs to provide possible etiologic insights as well as therapeutic targets for CHF., (Copyright © 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Background: Although several ECG algorithms have been proposed for differentiating the origins of outflow tract ventricular arrhythmia (OT-VA), their accuracy still is limited in cases with cardiac rotation., Objective: The purpose of this study was to assess whether a novel "cardiac rotation-corrected" transitional zone (TZ) index would be a useful marker for differentiating right ventricular outflow tract (RVOT) origin from aortic sinus cusp (ASC) origin., Methods: Surface ECGs of OT-VAs with left bundle branch block morphology and inferior axis in 112 patients who were successfully ablated in the RVOT (n = 87) or the ASC (n = 25) were analyzed. The TZ index was defined according to the site of R-wave transition of sinus beats and OT-VAs., Results: The TZ index was significantly lower in the ASC origin than in the RVOT origin (-1.2 ± 0.9 vs 0.3 ± 0.7, P <.0001). A cutoff value of the TZ index <0 predicted the ASC origin with 88% sensitivity and 82% specificity. The previously reported R-wave duration index ≥ 50% had a high specificity of 85% but a low sensitivity of 44%, and R/S-wave amplitude index ≥ 30% had 68% sensitivity and 79% specificity. The area under the curve by receiver operating characteristic curve analysis was 0.90 for the TZ index, which was significantly higher than the R-wave duration index and R/S-wave amplitude index of 0.74 and 0.76, respectively., Conclusion: This novel TZ index can be a more useful marker for differentiating RVOT origin from ASC origin., (Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Mechanical dyssynchrony is an important factor in the response to cardiac resynchronization therapy (CRT). However, no echocardiographic measure can improve prediction of case selection for CRT., Objective: The purpose of this study was to assess the efficacy of a newly combined echocardiographic index for ventricular dyssynchrony and contractility using speckled tracking strain analysis to predict responders to CRT., Methods: Forty-seven patients with severe heart failure in New York Heart Association functional class III/IV, left ventricular ejection fraction /=130 ms were included in the study. Echocardiography was performed, and a novel index (i-Index), the product of radial dyssynchrony and radial strain, was calculated. Responder to CRT was defined as a patient with a >/=15% decrease in left ventricular end-systolic volume at 6-month follow-up., Results: Thirty-two patients (68%) were classified as responders. The i-Index was significantly higher in responders than in nonresponders (3,450 +/- 1180 vs 1,481 +/- 841, P <.001). The area under receiver operator characteristic curve was 0.92 for the i-Index, which was better than the index of radial dyssynchrony only (0.74). A cutoff value of i-Index >2,000 predicted responders with 94% sensitivity and 80% specificity. The index using only radial dyssynchrony had 81% sensitivity and 53% specificity. Furthermore, i-Index decreased in responders (1,985 +/- 1261, P <.001) but not in nonresponders (1,684 +/- 866, P = .48)., Conclusion: Our findings suggest that a novel combined index by radial strain echocardiography might be a predictor of response to CRT. The value of this novel echocardiographic index requires further assessment in larger studies., (Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Oxidative stress is associated with atrial fibrillation (AF). However, little is known about the relationship between serum markers of oxidation and electrical activity in patients with AF., Objective: The purpose of this study was to investigate the possible association between serum markers of reactive oxidative metabolism and atrial remodeling in paroxysmal and persistent AF., Methods: Derivatives of reactive oxidative metabolites (DROM), an index of oxidative stress, were measured in 306 consecutive patients with AF (225 paroxysmal, 81 persistent) undergoing radiofrequency (RF) catheter ablation. Filtered P-wave duration by P-wave signal-averaged ECG and levels of high-sensitivity C-reactive protein (CRP) as an inflammatory marker also were measured., Results: Patients were followed up for 1.2 +/- 0.8 years. DROM levels in patients with persistent AF were significantly higher than in patients with paroxysmal AF (341.6 +/- 85.5 Carratelli [Carr] units vs 305.0 +/- 77.7 Carr units, P <.001). DROM levels showed a tighter, positive correlation with filtered P-wave duration in persistent AF patients (r = 0.56, P <.001) than in all AF patients (r = 0.13, P <.05). DROM levels also showed a weaker but significant correlation with high-sensitivity CRP in patients with AF. Kaplan-Meier analysis revealed that the highest quartile of basal DROM levels exhibited a significantly higher AF recurrence rate after RF catheter ablation in patients with paroxysmal AF (P <.01)., Conclusion: Serum markers of oxidative stress reflect atrial conduction disturbance and predict AF recurrence after RF catheter ablation in paroxysmal AF patients. DROM could serve as a biomarker for predicting risk of AF recurrence after RF catheter ablation.

Background: The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) activator pioglitazone antagonizes angiotensin II actions and possesses anti-inflammatory and antioxidant properties in vitro. There is evidence that pioglitazone improves ventricular remodeling in some experimental models., Objective: The purpose of this study was to assess the effects of pioglitazone on arrhythmogenic atrial structural remodeling versus the effects of the angiotensin II type 1 receptor blocker candesartan in a rabbit model of congestive heart failure., Methods: Rabbits subjected to ventricular tachypacing at 380 to 400 bpm for 4 weeks in the absence and presence of treatment with pioglitazone, candesartan, and combined pioglitazone and candesartan were assessed by electrophysiologic study, atrial fibrosis measurements, and cytokine expression analyses., Results: Atrial fibrillation (AF) lasting longer than 2 seconds was induced in no nonpaced controls but in all ventricular tachypacing-only rabbits (mean duration of AF: 8.0 +/- 1.4 seconds). Pioglitazone reduced the duration of AF (3.5 +/- 0.2 seconds, P <.05) and attenuated atrial structural remodeling, with significant reductions in interatrial activation time (50 +/- 2 ms vs 41 +/- 2 ms, P <.05) and atrial fibrosis (16.8% +/- 0.8% vs 10.9% +/- 0.7%, P <.05; control 1.6% +/- 0.2%), effects comparable to those of candesartan (duration of AF: 3.0 +/- 0.2 seconds; activation time 44 +/- 2 ms; fibrosis: 9.4% +/- 0.6%). Both pioglitazone and candesartan reduced transforming growth factor-beta1, tumor necrosis factor-alpha, and activated extracellular signal-regulated kinase expression similarly, but neither affected p38-kinase or c-Jun N-terminal kinase activation. The effects of combined pioglitazone and candesartan therapy were not significantly different from the effects of pioglitazone or candesartan alone., Conclusion: Pioglitazone can attenuate congestive heart failure-induced atrial structural remodeling and AF promotion, with effects similar to those of candesartan. PPAR-gamma may be a potential therapeutic target for human AF.

Background: The left atrial appendage (LAA) is one of the major sources of focal atrial tachycardias (ATs)., Objective: The purpose of this study was to investigate the detailed electrophysiologic characteristics and catheter ablation of focal ATs originating from the LAA., Methods: The study population consisted of 47 consecutive patients with 50 focal ATs originating from the left atrium (LA): LAA in 13, left pulmonary veins (PVs) in 14, right PVs in 12, and mitral annulus in 11. Programmed electrical stimulation and pharmacologic testing were performed to examine the mechanism of LAA AT. Left atriography was performed prior to radiofrequency ablation to identify the focus in the LAA., Results: The mechanism of LAA AT was automaticity in 11 and triggered activity in 2. The 13 LAA foci were located mainly at the LAA base: 11 on the medial side and 2 on the lateral side. Atrial activation sequences within the distal coronary sinus were helpful in differentiating these LAA foci. The criterion of a negative P wave in leads I and aVL indicating an LAA AT focus was associated with sensitivity of 92.3%, specificity 97.3%, positive predictive value 92.3%, and negative predictive value 97.3%. No complications occurred in any of the 13 patients. All 13 patients were free of atrial arrhythmias without any antiarrhythmic drugs during follow-up of 8 +/- 3 years., Conclusion: LAA ATs have typical electrophysiologic and electrocardiographic characteristics that are helpful in guiding radiofrequency catheter ablation.

Background: How extensive should an appropriate pulmonary vein (PV) ablation be is a matter of controversy., Objective: The study's aim was to investigate the efficacy of minimally extensive PV ablation for isolating the PV antrum (PVA) with the guidance of electrophysiological parameters., Methods: Fifty-five consecutive symptomatic paroxysmal atrial fibrillation (PAF) patients underwent PV mapping with a multielectrode basket catheter (MBC). A 31-mm MBC was deployed in 3-4 PVs as proximally as possible without dislodgement, and the longitudinal PV mapping enabled us to recognize single sharp potentials formed by the total fusion of the PV and left atrial potentials around the PV ostium or the transverse activation patterns that were observed. Those potentials were defined as PVA potentials. Radiofrequency ablation was performed circumferentially targeting PVA potentials with the end point being their elimination., Results: After circumferential PVA ablation, electrical disconnection was achieved in 77% and residual PVA conduction gaps were observed in 23% of all targeted PVs. Those residual conduction gaps were mainly located at the border between ipsilateral PVs (42%) and between the left PVs and left atrial appendage (33%) and were eliminated by a mean of 3 +/- 2 minutes of local radiofrequency deliveries. During the follow-up period (11 +/- 5 months), 46 (84%) patients were free of symptomatic PAF without any anti-arrhythmic drugs. No PV stenosis or spontaneous left atrial flutter occurred., Conclusions: Electrophysiological PVA ablation with an MBC is feasible and effective for curing PAF because this minimally extensive PVA isolation technique targets the optimal sites, achieving both high efficacy and safety.

Objectives: The purpose of this study was to investigate the efficacy of a novel catheter mapping technique for predicting atrial fibrillation (AF) foci., Background: Most AF originates from pulmonary veins (PVs), but some originate from the right atrium., Methods: We developed an algorithm by correlating the cardiac recordings obtained from multielectrode catheters placed in the posterior right atrium (RA) and esophagus during pacing from the PVs and superior vena cava (SVC) or crista terminalis (CT) in 10 AF patients. We tested the algorithm's accuracy prospectively in 46 AF patients., Results: During pacing from the left PVs, the esophageal potentials preceded all other potentials. During pacing from both the right PVs and SVC-CT, the first component (FP) of the double potential (DP) recorded in the posterior RA preceded all other potentials. The amplitude of the FP was higher than that of the second DP component during pacing from the SVC-CT, whereas the reverse occurred from the right PVs. The activation sequence of the FPs and esophageal potentials was from superior to inferior during pacing from the superior PVs, whereas the reverse occurred from the inferior PVs. The accuracy of predicting 34 foci in the right PVs, 28 foci in left PVs, and 6 foci in SVC-CT was 100% for all, respectively. The accuracy of discriminating foci in the superior PVs from those in the inferior PVs was 97% in the right PVs and 96% in the left PVs., Conclusions: The technique using mapping catheters placed in the posterior RA and esophagus is feasible and effective for mapping and ablating AF.

Background: Although exercise-induced electrocardiographic ST segment changes are used to detect coronary artery disease (CAD), their diagnostic value is markedly decreased in patients with left ventricular (LV) hypertrophy. There have been no reports concerning postexercise systolic blood pressure (SBP) response in patients with ultrasound echocardiographic (UCG) LV hypertrophy and CAD., Methods: Sixty-six patients with both UCG-LV hypertrophy (LV mass index 134 g/m2 or greater for men or 110 g/m2 or greater for women) and positive ST depression of at least 0.1 mV during treadmill exercise testing were studied. Coronary cineangiograms showed normal coronary arteries in 19 patients (group 1) and significant CAD in 47 patients (group 2). The SBP ratio was calculated by dividing the SBP 3 min after exercise (3 min SBP) by the SBP at peak exercise (peak SBP)., Results: There were no significant differences between the two groups in LV mass index, SBP at rest, exercise duration, ST depression (at rest and exercise-induced) or 3 min SBP. However, the SBP ratio was significantly higher in group 2 compared with group 1 (0.87+/-0.11 versus 1.01+/-0.18; P=0.004). Analysis of relative cumulative frequency distributions revealed an SBP ratio of 0.92 as the cutoff point for distinguishing a UCG-LV hypertrophy patient with CAD from one without CAD. The sensitivity, specificity and accuracy with an SBP ratio of 0.92 and an ST segment depression of at least 0.1 mV on treadmill exercise testing for detecting CAD in patients with UCG-LV hypertrophy were 77%, 74% and 76%, respectively., Conclusion: These findings suggest that the ratio of early post-exercise SBP to peak exercise SBP may be diagnostically useful in detecting CAD in patients with positive ST depression during an exercise test and UCG-LV hypertrophy.

Plasminogen activator inhibitor-1 (PAI-1) plays a critical role in tissue fibrosis by inactivating matrix metalloproteinases, which might effect on the progression of left ventricular dysfunction. However, little has been known about the expression of PAI-1 during cardiac remodeling. We used a mouse model of myocardial infarction (MI) by coronary ligation, in which the progression of left ventricular remodeling was confirmed by echocardiography. Histological examination showed that interstitial and perivascular fibrosis progressed in the post-MI (PMI) heart at 4 weeks after the procedure. We observed the dramatic induction of cardiac PAI-1 mRNA and PAI-1 antigen in plasma in the PMI mice, as compared with the sham-operated (sham) mice. In situ hybridization analysis demonstrated that strong signals for PAI-1 mRNA were localized to cardiomyocytes in the border of infarct area and around fibrous lesions, and to perivascular mononuclear cells, which seemed to be mast cells, only in hearts of the PMI mice. Importantly, less development of cardiac fibrosis after MI was observed in mice deficient in PAI-1 as compared to wild-type mice. The mRNA expression of cytokines, transforming growth factor-beta, and tumor necrosis factor-alpha, was also increased in hearts of the PMI mice, but not in the sham mice. These observations suggest that cardiomyocytes and mast cells contribute to the increased PAI-1 expression, resulting in the development of interstitial and perivascular fibrosis in the PMI heart, and that the regional induction of cytokines may be involved in this process.

Background: Of 41 patients who had undergone a left-sided simple maze procedure, 4 (9.8%) developed repetitive tachycardia due to atrial flutter, and required radiofrequency catheter ablation. Linear ablation of the right atrial isthmus was effective to treat atrial flutter., Methods: We conducted an electrophysiologic study of atrial flutter and determined its reentry circuit on the atrium. We consider how to reduce atrial flutter after the left-sided simple maze procedure., Results: Common atrial flutter through the right atrial isthmus was induced in all 4 patients, and linear ablation on the right atrial isthmus was effective in 3 of these. An incisional atrial flutter around the right atriotomy was also induced in 2 of 4 patients; both were successfully treated by linear ablation between the right atriotomy and the inferior vena cava., Conclusions: Common atrial flutter through the right atrial isthmus is a risk after the left-sided simple maze procedure. When a left-sided simple maze procedure is performed, sufficient cryoablation on the right atrial isthmus of the arrested heart should be administered to prevent postoperative atrial flutter.