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Atrial fibrillation (AF) is a common cardiac arrhythmia, with structural and electrical remodeling being significant risk factors for recurrence post-catheter ablation. The advent of high-power short-duration pulmonary vein isolation (HPSD-PVI) presents a novel approach, potentially enhancing procedural success rates through the creation of transmural lesions without overheating. This study investigates the predictors of atrial tachyarrhythmia (ATA) recurrence and compares outcomes between HPSD-PVI and conventional PVI techniques. A total of 1005 patients undergoing radiofrequency catheter ablation (RFA) for AF were retrospectively analyzed in this study. The cohort was divided based on the ablation strategy: conventional PVI from February 2013 to September 2018, and HPSD-PVI from October 2018 onwards. The primary objective was to compare the predictors of ATA recurrence and the outcome between the two groups. Among 969 patients analyzed after exclusions, independent predictors of recurrence differed between groups; higher CHADS 2 /CHA 2 DS 2 -VASc scores and lower left ventricular ejection fraction (LVEF) were significant in the HPSD-PVI group, while non-paroxysmal AF, larger left atrial volume index (LAVI), and longer AF history were predictors in the conventional PVI group. The HPSD-PVI group showed a trend toward lower ATA recurrence rates compared to the conventional PVI group in the propensity-score-matched (PSM) cohort (log-rank test, p = 0.06). Higher CHADS 2 /CHA 2 DS 2 -VASc scores and lower LVEF were also independent predictors of ATA recurrence in the PSM cohort., (© 2024. Springer Nature Japan KK, part of Springer Nature.)

Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

A 26-year-old man with long QT syndrome (LQTS) underwent subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation. The patient exhibited sinus bradycardia relative to his age. The heart rate decreased, and the QT interval became longer with the administration of β-blockers, the first-line therapy for LQTS. The patient experienced frequent S-ICD discharges. Subsequently, a single-chamber pacemaker was implanted, and the 12-lead electrocardiogram showed atrial pacing and ventricular sensing at 60 beats per minute with a shorter QTc interval. After converting to "double-device therapy," the patient did not experience any ventricular arrhythmia events., Competing Interests: The authors have no competing interests to disclose.Dr. Higuchi, Dr. Yagishita and Dr. Shoda belong to the same endowed department established by contributions from Medtronic Japan, BostonScientific, Biotronik Japan, and Abbott Medical., (© 2024 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society.)

Background and Objective: Treatment for atrial fibrillation (AF) has evolved significantly, with pulmonary vein isolation (PVI) becoming an established treatment. However, the outcomes following catheter ablation for persistent AF remain unsatisfactory. Hybrid catheter-surgical ablation has emerged as a therapeutic approach for persistent AF, combining the strengths of both interventions. The purpose of this narrative review is to comprehensively examine the current state of knowledge regarding hybrid ablation for AF., Methods: A thorough PubMed search using the terms "hybrid ablation", "atrial fibrillation", "catheter ablation", and "guideline on cardiology" within the timeframe of 1980 to 2024 resulted in 138,969 articles. Consensus on the selected articles was reached through a series of structured meetings and discussions., Key Content and Findings: PVI has demonstrated higher sinus rhythm maintenance rates, especially for paroxysmal AF. However, the efficacy is not as high for persistent AF. Additional ablation strategies, such as linear ablation, complex fractionated atrial electrogram ablation, low voltage zone ablation as well as posterior wall isolation, lack consistent evidence of effectiveness. Hybrid ablation, involving collaboration between cardiac surgeons and electrophysiologists, presents a promising alternative for hard-to-treat AF. Recent studies report favorable outcomes of hybrid ablation, with atrial arrhythmia-free rates ranging from 53.5% to 76%, surpassing those of catheter ablation alone, which might result from better lesion durability or intervention for non-PV foci and left atrial appendage excision or closure during hybrid ablation. The rate of complications associated with hybrid ablation is higher than catheter ablation alone., Conclusions: While favorable outcomes of hybrid ablation for persistent AF have been reported, it is not recommended for all AF patients due to its invasiveness compared to catheter ablation. Additionally, some patients with persistent AF maintain sinus rhythm with catheter ablation alone. More clinical data are needed to determine which patients are suitable candidates for hybrid ablation., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-23-1671/coif). The series “Surgical Treatment of Arrhythmias” was commissioned by the editorial office without any funding or sponsorship. The authors have no other conflicts of interest to declare., (2024 Journal of Thoracic Disease. All rights reserved.)

Competing Interests: Funding Support and Author Disclosures Drs Yagishita and Shoda belong to the same endowed department established by contributions from Medtronic Japan, Boston-Scientific, Biotronik Japan, and Abbott Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Competing Interests: The authors have no competing interests to disclose.

Background: The association between the T-peak to T-end interval (Tp-e) and ventricular arrhythmia (VA) events in cardiac sarcoidosis (CS) is unknown. The purpose of this study was to investigate whether Tp-e was associated with VA events in CS patients with implantable cardioverter defibrillators (ICDs) or cardiac resynchronization therapy defibrillators (CRT-Ds)., Methods and results: We retrospectively studied 50 patients (16 men; mean [±SD] age 56.3±10.5 years) with CS and ICD/CRT-D. The maximum Tp-e in the precordial leads recorded by a 12-lead electrocardiogram after ICD/CRT-D implantation was evaluated. The clinical endpoint was defined as appropriate ICD therapy. During a median follow-up period of 85.0 months, 22 patients underwent appropriate therapy and 10 patients died. Kaplan-Meier analysis revealed that the probability of the clinical endpoint was 28.3% at 2 years and 35.3% at 4 years. The optimal cut-off value of the Tp-e for the prediction of the clinical endpoint was 91 ms, with a sensitivity of 72.7% and a specificity of 87.0% (area under the curve=0.81). Multivariate Cox regression analysis showed that Tp-e ≥91 ms (hazard ratio [HR] 5.10; 95% confidence interval [CI] 1.99-13.1; P<0.001) and a histological diagnosis of CS (HR 3.84; 95% CI 1.28-11.5; P=0.016) were significantly associated with the clinical endpoint., Conclusions: Tp-e ≥91 ms was a significant predictor of VA events in patients with CS and ICD/CRT-D.

Background: The long-term relationship between fracture-prone implantable cardioverter-defibrillator (ICD) leads and poor prognosis remains unclear in Japanese patients., Methods: We conducted a retrospective review of the records of 445 patients who underwent implantation of advisory/Linox leads (Sprint Fidelis, 118; Riata, nine; Isoline, 10; Linox S/SD, 45) and non-advisory leads (Endotak Reliance, 33; Durata, 199; Sprint non-Fidelis, 31) between January 2005 and June 2012 at our hospital. The primary outcomes were all-cause mortality and ICD lead failure. The secondary outcomes were cardiovascular mortality, heart failure (HF) hospitalization, and the composite outcome of cardiovascular mortality and HF hospitalization., Results: During the follow-up period (median, 8.6 [4.1-12.0] years), there were 152 deaths: 61 (34%) in patients with advisory/Linox leads and 91 (35%) in those with non-advisory leads. There were 32 ICD lead failures: 27 (15%) in patients with advisory/Linox leads and five (2%) in those with non-advisory leads. Multivariate analysis for ICD lead failure demonstrated that the advisory/Linox leads had a 6.65-fold significantly greater risk of ICD lead failure than non-advisory leads. Congenital heart disease (hazard ratio 2.51; 95% confidence interval 1.08-5.83; p  = .03) could also independently predict ICD lead failure. Multivariate analysis for all-cause mortality demonstrated no significant association between advisory/Linox leads and all-cause mortality., Conclusions: Patients who have implanted fracture-prone ICD leads should be carefully followed up for ICD lead failure. However, these patients have a long-term survival rate comparable with that of patients with non-advisory ICD leads in Japanese patients., Competing Interests: None., (© 2023 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society.)

Background: Appropriate implantable cardioverter-defibrillator (ICD) shocks are associated with an increased risk of mortality and heart failure (HF) events. The first appropriate shock may occur late after implantation. However, whether the timing of the first appropriate shock influences prognosis is unknown. This study aimed to evaluate the clinical significance of the timing of the first appropriate shock in patients with ICD., Methods: This retrospective and observational study enrolled 565 consecutive ICD patients. Patients who received an appropriate shock were divided into the early group (first appropriate shock <1 year after ICD implantation) and late group (first appropriate shock ≥1 year after ICD implantation). All-cause mortality was compared between the two groups., Results: Over a median follow-up of 5.6 years, 112 (19.8%) patients received an appropriate shock, including 32 patients (28.6%) in the early group and 80 patients (71.4%) in the late group. Comparisons of baseline characteristics at ICD implantation revealed that the late group was more likely to receive cardiac resynchronization therapy (66.3% vs. 31.3%, p < 0.001), ICD for primary prevention (60.0% vs. 31.3%, p = 0.001), and angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker treatment (88.8% vs. 71.9%, p = 0.028). Survival after shock was significantly worse in the late group than in the early group (p = 0.027). In multivariable Cox proportional hazards analysis, the late group had an increased risk of all-cause mortality compared with the early group (HR: 2.22; 95% CI 1.01-4.53; p = 0.029). In both groups, the most common cause of death was HF., Conclusions: Late occurrence of the first appropriate ICD shock was associated with a worse prognosis compared with early occurrence of the first appropriate shock. Cardiac death was the most common cause of death in patients who experienced late occurrence of the first appropriate ICD shock, resulting from HF in most cases., (© 2022 Wiley Periodicals LLC.)

Atrial fibrillation (AF) ablation can improve left ventricular ejection fraction (LVEF) and renal function and can even reduce mortality in patients with impaired LVEF. However, the effect of post-ablation cardiorenal dysfunction on the prognosis of patients with impaired LVEF who underwent AF ablation remains unclear. Of the 1243 consecutive patients undergoing AF ablation, the prognosis of 163 non-dialysis patients who underwent AF ablation with < 50% LVEF was evaluated. The primary outcome was a composite of all-cause mortality, heart failure hospitalization, and a need for modification of the treatment for heart failure. During the median follow-up of 4.2 years after the first AF ablation procedure, the primary outcome occurred in 30 of 163 patients (18%). The receiver operating characteristic curve analysis demonstrated that the post-LVEF (LVEF within 1 year after the procedure, and before the occurrence of primary outcome) had larger areas under the curve (0.70) than the pre-LVEF (LVEF before the procedure), and the most optimal cutoff value was LVEF ≤ 42%. Multivariate analysis demonstrated that patients with post-LVEF ≤ 42% and worsening renal function (WRF; an absolute increase in serum creatinine [SCr] ≥ 0.3 mg/dL compared with the SCr at baseline within 1 year after the procedure and before the occurrence of primary outcome) had a 3.4- to 4.3-fold and 3.4- to 3.7-fold higher risk of the primary outcome compared with those without these predictors, respectively. Patients were categorized using post-LVEF ≤ 42% and WRF as follows: group 1 (post-LVEF > 42% without WRF), group 2 (post-LVEF ≤ 42% without WRF), group 3 (post-LVEF > 42% with WRF), and group 4 (post-LVEF ≤ 42% with WRF). Group 4 had a 15.8-fold (P = 0.0001) higher risk of the primary outcome compared with group 1 after adjusting for pre-procedural factors. In patients with impaired LVEF undergoing AF ablation, post-LVEF ≤ 42% and WRF were independent predictors of poor prognosis. The combination of post-LVEF ≤ 42% and WRF is strongly associated with a poor prognosis in patients with AF undergoing ablation, who with these post-ablation cardiorenal dysfunction may have to be treated more intensively after AF ablation., (© 2022. Springer Japan KK, part of Springer Nature.)

Background: Transvenous lead extraction (TLE) is an established procedure for the management of cardiovascular implantable electronic devices. However, some difficulties and risks of complications still exist, especially in old and adhered leads. Evolution RL (Cook Medical, Bloomington, IN, USA) is a newly introduced device for TLE; however, no clinical results have been reported in Japan, and the results with older leads are unknown. We investigated the efficacy and safety of Evolution RL and its usefulness for old leads at two TLE centers in Japan., Methods: A total of 27 consecutive patients who underwent lead extraction using Evolution RL at Shinshu University Hospital and Tokyo Women's Medical University Hospital from September 2017 to December 2019 were retrospectively enrolled. We examined the backgrounds of the patients and leads and investigated the efficacy and safety of the procedures. We divided the leads into two groups according to the number of years of implantation (10 years) and compared the results., Results: Among the 27 patients, 20 (74.1%) were men, and the median age was 62 (14-91) years. The total number of leads was 58, and the median implantation duration was 136 months (8-448). We achieved clinical success in all patients and complete procedural success in 24 patients (88.9%). In three patients, the broken tip of the lead remained in the heart. No major complications were noted. Of the 58 leads, there were 34 leads with more than 10 years of implantation, with significantly more Evolution RLs used (94.1% vs. 54.2%, p = 0.001) and significantly higher percentages of Evolution 11Fr, 13Fr, and steady sheaths used (79.4% vs. 33.3%, p = 0.001, 52.9% vs. 16.7%, p = 0.006, and 64.7% vs. 20.8%, p = 0.001, respectively)., Conclusions: In two TLE centers in Japan, Evolution RL was shown to be safe and effective, even in leads older than 10 years., Competing Interests: Declaration of competing interest The authors declare no conflict of interest for this article., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The relationship between pre-ablation left ventricular diastolic dysfunction (LVDD) and prognosis in patients with left ventricular systolic dysfunction (LVSD) undergoing atrial fibrillation (AF) ablation remains unclear., Methods: The prognosis of 173 patients with impaired left ventricular ejection fraction (<50%) who underwent AF ablation was examined. The primary outcome was a composite of all-cause mortality, heart failure (HF) hospitalization, and worsening HF symptoms requiring unplanned outpatient intensification of decongestive therapy., Results: During the follow-up period (median, 3.5 years), the primary outcome after AF ablation occurred in 28 patients (16%). The receiver operating characteristic curve analysis showed that early septal diastolic mitral annular velocity (e') had a larger area under the curve (0.70) than other LVDD parameters, and optimal cut-off values of LVDD, represented by e', septal E (early diastolic left ventricular filling velocity)/e', and peak tricuspid valve regurgitation velocity (TRV), were 5.0 cm/s, 13.2, and 2.5 m/s, respectively. Multivariate analysis revealed that e' ≤5.0 cm/s (standard hazard ratio [HR], 3.87; 95% confidence interval [CI], 1.73-8.69; p = 0.001), septal E/e' ≥13.2 (HR, 3.62; 95% CI, 1.60-8.21; p = 0.002), and peak TRV ≥ 2.5 m/s (HR, 2.42; 95% CI, 1.13-5.16; p = 0.02) independently predicted the outcome. Patients with New York Heart Association functional status ≥ III had a 3.3-4.5-fold higher risk of the outcome., Conclusions: LVDD or severe HF symptoms predict poor outcomes in patients with LVSD undergoing AF ablation. Therefore, patients with LVDD or severe HF symptoms should receive more intensive treatment even after AF ablation., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author(s).)

Background: Reports of long-term outcomes after atrial fibrillation (AF) ablation for tachycardia-bradycardia syndrome (TBS) are limited. This study aimed to investigate the impact of radiofrequency catheter ablation (RFCA) on clinical outcomes in patients with TBS., Methods: Among 1669 patients who underwent AF ablation between January 2010 and April 2020, we retrospectively enrolled 53 patients (62.3% males; age, 67.1 ± 7.0 years) who had been diagnosed with TBS before RFCA for paroxysmal AF (TBS group). After 1:2 propensity score-matching based on age, gender, AF type, and left atrial dimension, 106 patients were assigned to the control group (non-TBS group). The atrial tachyarrhythmia (ATA) recurrence rate and rate of avoidance of permanent pacemaker implantation (PMI) were examined., Results: During a median follow-up period of 37.7 months, the ATA recurrence rate after a single ablation procedure was significantly higher in the TBS group than in the non-TBS group (51.0% vs. 38.5%; log-rank p  = .008); however, the ATA recurrence rate after the final ablation procedure did not significantly differ between groups. In the TBS group, the rate of PMI avoidance after AF ablation was 92.5%. A Cox-regression multivariate analysis revealed that the presence of non-pulmonary vein/superior vena cava premature atrial contractions (odds ratio, 3.38; 95% confidence interval, 1.49-7.66; p  = .004) was an independent predictor of ATA recurrence in the TBS group., Conclusions: Patients with TBS had higher ATA recurrence rates after the first ablation procedure compared to those without TBS. However, ATA recurrence after AF ablation did not necessarily result in PMI for TBS patients., Competing Interests: None., (© 2022 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of the Japanese Heart Rhythm Society.)

Objectives: The goal of this study was to evaluate whether intermittent VNS reduces electrical heterogeneities and arrhythmia inducibility during sympathoexcitation., Background: Sympathoexcitation increases the risk of ventricular tachyarrhythmias (VT). Vagal nerve stimulation (VNS) has been antiarrhythmic in the setting of ischemia-driven arrhythmias, but it is unclear if it can overcome the electrophysiological effects of sympathoexcitation in the setting of chronic myocardial infarction (MI)., Methods: In Yorkshire pigs after chronic MI, a sternotomy was performed, a 56-electrode sock was placed over the ventricles (n = 17), and a basket catheter was positioned in the left ventricle (n = 6). Continuous unipolar electrograms from sock and basket arrays were obtained to analyze activation recovery interval (ARI), a surrogate of action potential duration. Bipolar voltage mapping was performed to define scar, border zone, or viable myocardium. Hemodynamic and electrical parameters and VT inducibility were evaluated during sympathoexcitation with bilateral stellate ganglia stimulation (BSS) and during combined BSS with intermittent VNS., Results: During BSS, global epicardial ARIs shortened from 384 ± 59 milliseconds to 297 ± 63 milliseconds and endocardial ARIs from 359 ± 36 milliseconds to 318 ± 40 milliseconds. Dispersion in ARIs increased in all regions, with the greatest increase observed in scar and border zone regions. VNS mitigated the effects of BSS on border zone ARIs (from -18.3% ± 6.3% to -2.1% ± 14.7%) and ARI dispersion (from 104 ms 2 [1 to 1,108 ms 2 ] to -108 ms 2 [IQR: -588 to 30 ms 2 ]). VNS reduced VT inducibility during sympathoexcitation (from 75%-40%; P < 0.05)., Conclusions: After chronic MI, VNS overcomes the detrimental effects of sympathoexcitation by reducing electrophysiological heterogeneities exacerbated by sympathetic stimulation, decreasing VT inducibility., Competing Interests: Funding Support and Author Disclosures This study was funded by National Institutes of Health R01 HL148190 (to Dr Vaseghi). Dr Vaseghi has shares in NeuCures Inc; and has patents on neuromodulation at University of California, Los Angeles. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Indication for de novo cardiac resynchronization therapy (CRT) has been recommended in mild heart failure (HF) patients with left ventricular (LV) ejection fraction (LVEF) <50% and atrioventricular block (AVB). In contrast, the indication of CRT upgrade from right ventricular pacing (RVP) has been limited to severe HF patients with LVEF≤35% and AVB. This study examined LV volumetric responses and clinical outcomes in mild HF patients with AVB who underwent CRT upgrade, compared with those of de novo CRT patients., Methods: This retrospective study focused on patients with CRT due to AVB, mild HF at New York Heart Association class II and LVEF<50%. A total of 58 patients were divided into two groups: (1) 27 patients with CRT upgrade from RVP>40% (Upgrade group, UG), and (2) 31 patients with de novo CRT implantation (De novo group, DG). The echocardiographic assessment was performed at baseline and six months after CRT. The study endpoint was a combined endpoint with total mortality, HF hospitalization, or ventricular tachyarrhythmia events., Results: At six months after CRT, the LV end-systolic volume (LVESV) was significantly reduced in both groups (from 144.3±39.4 mL to 111.1±33.5 mL in UG, p<0.01; from 134.5±36.6 mL to 123.5±45.6 mL in DG, p<0.05); however, a significant improvement in LVEF was obtained in UG but not in DG (from 31.7±6.8% to 39.7±8.5% in UG, p<0.01; from 34.2±7.3% to 36.0±9.7% in DG, p=0.15). Consequently, the changes in LVESV and LVEF were significantly greater in UG than in DG. During the follow-up of 989 days, the survival rate for the composite events were similar between both groups (p=0.18)., Conclusions: LV reverse remodeling was significantly greater in UG than DG, and the incidence of clinical composite events at mid-term follow-up was equivalent between UG and DG. CRT upgrade could be an acceptable indication in mild HF patients dependent on RVP., Competing Interests: Declaration of Competing Interest D. Yagisihta, M. Shoda, and K.Ejima belong to an endowed department established by contributions from Medtronic Japan, Boston Scientific, Biotronik, and Abbott Medical. The other authors do not have grants, conflicts, or relationships with industry., (Copyright © 2021. Published by Elsevier Ltd.)

Background: Management of pacemaker (PM) infections among advanced aged patients possesses particular clinical challenges due to higher rates of concurrent cardiovascular disease and medical comorbidities. Novel leadless cardiac pacemakers (LCPs) may provide new opportunities for better management options in this population, however, there is limited data especially in Asian populations to guide the decision making., Methods: We reviewed 11 octogenarians (median age: 86 [minimum 82-maximum 90] years; male: 73%; median body mass index (BMI): 20.1 kg/m 2 ) who received Micra Transcatheter Pacing System (Medtronic Inc, Minneapolis, MN) implantations following transvenous lead extractions (TLEs) for PM infections., Results: All patients had more than two medical comorbidities (average 3.7 comorbidities). The indications for LCP implantations were atrioventricular block in four patients, atrial fibrillation bradycardia in five, and sinus node dysfunction in two. Eight patients (73%) were bridged with temporary pacing using active fixation leads (median interval of 14.0 days), while one with severe dementia underwent a concomitant LCP implantation and TLE during the same procedure. Successful TLEs and LCP implantations were successfully accomplished in all without any complications. The median time from the TLE procedure to discharge was 22 days (minimum 7-maximum 136). All patients remained free of infections during a mean follow-up period of 17.2 ± 6.5 months., Conclusions: LCP implantations were safe and effective after removing the entire infectious PM system in all octogenarians. The novel LCP technology may offer an alternative option for considering a re-implantation strategy after transvenous PM infections in elderly patients, particularly those with severe frailty and PM dependency., Competing Interests: >The authors have no conflict of interest to disclose., (Copyright and License information: Journal of Geriatric Cardiology 2021.)

Background: Acute pulmonary vein reconnection (PVR) is associated with long procedure times and large radiofrequency (RF) energy delivery during pulmonary vein isolation (PVI). Although the efficacy of high-power PVI (HP-PVI) has been recently established, the determinants of acute PVR following HP-PVI remain unclear., Methods: We evaluated data on 62 patients with paroxysmal atrial fibrillation undergoing unipolar signal modification (USM)-guided HP-PVI. A 50-W RF wave was applied for 3-5 seconds after USM. In the segments adjacent to the esophagus (SAEs), the RF time was limited to 5 seconds. Each circle was subdivided into six regions (segments), and the possible predictors of acute PVR, including minimum contact force (CF min ), minimum force-time integral (FTI min ), minimum ablation index (AI min ), minimum impedance drop (Imp-min), and maximum inter-lesion distance (ILD max ), were assessed in each segment., Results: We investigated 1162 ablations in 744 segments (including 124 SAEs). Acute PVR was observed in 21 (17%) SAEs and 43 (7%) other segments ( P  = .001). The acute PVR segments were characterized by significantly lower CF min , FTI min , AI min , and Imp-min values in the segments other than the SAEs and larger ILD max values in the SAEs. Furthermore, lower Imp-min and larger ILD max values independently predicted acute PVR in the segments other than the SAEs and SAEs (odds ratios 0.90 and 1.39 respectively). Acute PVR was not significantly associated with late atrial fibrillation recurrence., Conclusions: Avoiding PVR remains a challenge in HP-PVI cases, but it might be resolved by setting the optimal target impedance drop and lesion distance values., Competing Interests: Authors declare no conflict of interests for this article., (© 2021 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society.)

Background: The number of patients undergoing cardiac resynchronization therapy has increased. Consequently, there is increased frequency in the removal and reimplantation of coronary venous (CV) leads due to infection or malfunction., Methods and results: A total of 345 consecutive patients referred for lead(s) extraction were reviewed. Of these, 34 patients who underwent a CV lead removal were investigated. The indications for CV leads removal were device-related infections in 29 patients and lead malfunctions in 5 patients. The average duration of the CV leads was 4.1±3.8 years. All CV leads were successfully removed without any major complications, except for 1 in-hospital death. Successful CV lead removal by simple traction (ST) was achieved in 21 patients (62%), whereas extraction tools were required in 13 patients (38%). Local infection and CV lead dwell time were significantly associated with successful ST (P=0.04 and P=0.014, respectively). CV lead re-implantation was successfully performed in 25 patients; however, a right-side approach was required in 92%, and occlusion/stenosis of the previous CV was observed in 80% of the patients., Conclusions: CV lead removal is relatively successful and safe. The presence of local infection and a shorter lead duration may enable successful ST of a CV lead. However, the re-implantation procedure should be well prepared for the complexity related to the right-side approach and occlusion/stenosis of the previous CV.

Objectives: This study sought to evaluate the prognostic value of the time interval from left ventricular (LV) pacing to the earliest onset of QRS complex (S-QRS) for long-term clinical outcomes in patients who underwent cardiac resynchronization therapy (CRT)., Background: The electrical latency during LV pacing evaluated by S-QRS is associated with local tissue property, and the S-QRS ≥37 ms has been previously proposed as an independent predictor of mechanical response to CRT., Methods: This study included 82 consecutive patients with heart failure with reduced LV ejection fraction (≤35%) and a wide QRS complex (≥120 ms) who underwent CRT. Patients were divided into a short S-QRS group (SS-QRS; <37 ms) and a long S-QRS group (LS-QRS; ≥37 ms). The primary endpoint was total mortality, including LV assist device implantation or heart transplantation, whereas the secondary endpoint was total mortality or HF hospitalization., Results: S-QRS was 25.9 ± 5.3 ms in SS-QRS and 51.5 ± 13.7 ms in LS-QRS (p < 0.01), and baseline QRS duration and electrical activation at the LV pacing site (i.e., Q-LV) were similar. During mean follow-up of 44.5 ± 21.1 months, 24 patients (29%) reached the primary endpoint, whereas the secondary endpoints were observed in 47 patients (57%). LS-QRS had significantly worse event-free survival for both endpoints. LS-QRS was an independent predictor of total mortality (hazard ratio: 2.6; 95% confidence interval: 1.11 to 6.12; p = 0.03) and the secondary composite events (hazard ratio: 2.4; 95% confidence interval: 1.31 to 4.33; p < 0.01)., Conclusions: The S-QRS ≥37 ms at the LV pacing site was a significant predictor of total mortality and HF hospitalization. S-QRS-guided optimal LV lead placement is critical in patients who receive CRT., Competing Interests: Funding Support And Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Renal dysfunction is a known risk of sudden cardiac death in patients with ischemic heart disease. However, the association between renal dysfunction and sudden death in hypertrophic cardiomyopathy (HC) patients remains unknown. This study investigated the significance of an impaired renal function for the sudden death risk in a cohort of patients with HC. We included 450 patients with HC (mean age 52.9 years, 65.1% men). The estimated glomerular filtration rate (eGFR) was evaluated at the time of the initial evaluation. Renal dysfunction was defined as an eGFR <60 ml/min/1.73 m 2 . Renal dysfunction was found in 171 patients (38.0%) at the time of enrollment. Over a median (IQR) follow-up period of 8.8 (5.0 to 12.5) years, 56 patients (12.4%) experienced the combined end point of sudden death or potentially lethal arrhythmic events, including 20 with sudden death (4.4%), 11 resuscitated after a cardiac arrest, and 25 with appropriate implantable defibrillator shocks. Patients with renal dysfunction were at a significantly higher risk of sudden death (Log-rank p = 0.034) and the combined end point (Log-rank p <0.001) than patients without renal dysfunction. After adjusting for the highly imbalanced baseline variables, the eGFR remained as an independent correlate of the combined end point (adjusted hazard ratio: 1.24 per 10 ml/min decline in the eGFR; 95% confidence interval 1.04 to 1.47; p = 0.013). In conclusion, an impaired renal function may be associated with an incremental risk of sudden death or potentially lethal arrhythmic events in patients with HC., (Copyright © 2020 Elsevier Inc. All rights reserved.)

A 42-year-old woman with tricuspid atresia who underwent a Fontan surgery (atrio-pulmonary connection) was admitted to our hospital due to symptomatic ventricular tachycardia (VT). A defibrillation lead was implanted in a distal site of a coronary vein since there was no usual entry to the ventricle. Ventricular pacing was impossible due to the high threshold, however, good sensing was obtained. Three years later, she felt palpitations and a subsequent shock therapy while climbing stairs. The cardioverter data showed that an appropriate cardioversion therapy successfully converted VT to normal rhythm., (© 2020 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Purpose: To determine the efficacy and identify the relevant factors for durable lesion creation in pulmonary vein isolation (PVI) using a high-power short-duration (HPSD) strategy., Methods: Thirty-two consecutive patients who underwent PVI using HPSD (50 W) (HP group: HP-G) were compared with 32 controls using normal power (25-40 W) (conventional group: C-G). The segments were divided into 12 segments per group; thus, there were 768 segments for analysis. Radiofrequency (RF) ablation (RFA) was mainly performed under guidance with a unipolar electrogram at the distal tip of the ablation catheter in both groups. The high-power strategy reduced radiofrequency energy (P < 0.0001), RFA time (P < 0.0001), acute pulmonary vein reconnection (PVR) segments (P = 0.02), and several three-dimensional-mapping-related indices except for minimum impedance drop (Imp-min)., Results: There was a significant difference only in Imp-min between the subjects with acute PVR and those without in the HP-G (P = 0.002). Multivariate analysis revealed Imp-min to be the only independent predictor of the absence of PVR after adjusting for maximum inter-lesion distance and minimum ablation index (odds ratio [OR] 1.22, 95% confidence interval [CI] 1.07-1.39, P = 0.001). In the region-specific analysis, this was attenuated in posterior segments, where the HP strategy independently predicted the absence of PVR (OR 2.80 [95% CI 1.32-6.30], P = 0.007)., Conclusion: The HPSD strategy reduced RF time, RF energy, and three-dimensional mapping-related indices but also improved the acute outcome. The HP strategy may be a sophisticated strategy under guidance with the impedance drop rather than the ablation index.

Introduction: Some patients with cardiac implantable electronic devices (CIEDs) require atrial fibrillation (AF) ablation, and the superior vena cava (SVC) has been identified as one of the most common non-pulmonary vein foci of AF. This study aimed to investigate the interaction between SVC isolation (SVCI) and CIED leads implanted through the SVC., Methods and Results: We studied 34 patients with CIEDs who had undergone SVCI as part of AF ablation (CIED group), involving a total of 71 CIED leads. A similar number of age-, sex-, and AF type-matched patients without CIEDs formed a control group (non-CIED group). Patients' background and procedural characteristics were compared between the groups. In the CIED group, lead parameters before and after AF ablation were compared, and lead failure after AF ablation was also examined in detail. Procedural characteristics other than fluoroscopic time were similar in both groups. The success rate of SVCI after the final ablation procedure was 91.2% in the CIED group and 100% in the non-CIED group; however, these differences were not statistically significant. Lead parameters before and after the AF ablation did not significantly differ between the two groups. Lead failure was observed in three patients, with a sensing noise in one patient and an impedance increase in two patients after SVCI., Conclusion: SVCI was achievable without lead failure and significant change in lead parameters in most patients with CIEDs; however, it should be noted that lead failure was observed in 8.8% of the study patients after SVCI., (© 2020 Wiley Periodicals LLC.)

Background: Atrial fibrillation (AF) ablation is associated with a good prognosis; nevertheless, the effect of post-procedural systolic function on a patient's prognosis remains uncertain. Methods and Results: Of 1,077 consecutive patients undergoing AF ablation, the prognosis of 150 patients with abnormal left ventricular ejection fraction (LVEF; <50%) was evaluated. Patients were categorized as having reduced LVEF (rEF; LVEF <40%), mid-range ejection fraction (mrEF; 40%≤LVEF<50%), or preserved LVEF (pEF; LVEF ≥50%). Post-procedural LVEF, evaluated 3 months after the procedure, was post-rEF in 28 patients (19%), post-mrEF in 49 (33%), and post-pEF in 73 (49%). During the median follow-up of 31 months, the cumulative ratios of the composite outcome (heart failure hospitalization or death) in the post-rEF, post-mrEF, and post-pEF groups were 18%, 5%, and 2%, respectively, at 1 year and 50%, 13%, and 4%, respectively, at 3 years (P<0.0001). The post-rEF group had a 4.5- to 5.0-fold higher risk of the outcome compared with the post-pEF group, whereas the post-mrEF group showed no risk after adjusting for confounders, including age ≥65 years, preprocedural LVEF category, and recurrence of atrial tachyarrhythmia. Conclusions: Patients with post-mrEF had a comparable prognosis to those with post-pEF over a relatively long follow-up, whereas those with post-rEF had the poorest outcome of the 3 groups, regardless of preprocedural LVEF status., Competing Interests: N.H. is a member of Circulation Reports’ Editorial Team. The other authors have no conflicts of interest to declare., (Copyright © 2020, THE JAPANESE CIRCULATION SOCIETY.)

Introduction: Screening of coexistent typical atrial flutter (AFL) in patients with atrial fibrillation (AF) is sometimes challenging. This study investigated whether a prolonged right atrial conduction time (RACT) estimated by tissue Doppler imaging (TDI) predicts patients with concomitant AFL and AF., Methods and Results: We retrospectively analyzed 398 patients (mean age: 61.6 years, 73.4% men) undergoing catheter ablation of paroxysmal AF. The patients were classified into two groups according to whether they had evidence of AFL (N = 122, 30.7%) determined by a clinical observation (N = 68), induction during procedures (N = 33), or AFL recurrence after procedures (N = 21) or not (N = 276, 69.3%). The preoperative RACT, defined as a longer duration between the onset of the P-wave and peak A'-wave on the right atrial lateral wall or septal wall, and total atrial conduction time (TACT), defined as the same time duration on the left atrial lateral wall, were evaluated in all patients. Patients with evidence of AFL had a significantly longer RACT than those without AFL (p < .001). A multiple logistic regression and receiver operator characteristics curve analysis revealed the ratio of the RACT and TACT (RACT/TACT) was the independent and most superior accurate cofounder for predicting evidence of AFL (area under the curve: 0.867). When adding a discriminator of an RACT/TACT ≧ 93% into the conventional screening, 98.4% of the patients with evidence of AFL were estimated to be treated during the initial procedures., Conclusion: The estimated RACT/TACT using the TDI may be useful for predicting patients with concomitant AFL in patients with AF., (© 2020 Wiley Periodicals LLC.)

Background: In pulmonary vein isolation, the regional differences in the ablation index (AI) and interlesion distance (ILD) remain unclear. This study aimed to evaluate the association between the AI, ILD, and other relevant indices with pulmonary vein reconnections (PVRs) during the surgical intervention with a focus on the heterogeneous regional variability through a retrospective analysis., Methods: We divided the wide area circumferential ablation (WACA) region into 12 segments in 32 consecutive patients, which resulted in a 384 segment analysis to evaluate the association of the minimum AI (AI min) and maximum ILD (ILD max) with acute PVRs, which were defined as spontaneous PVRs or dormant conduction after adenosine triphosphate administration., Results: Acute PVRs were observed in 48 (13%) segments and 40 (63%) WACA regions. The AI min was significantly lower and ILD max greater in segments with PVRs than in those without (372 vs 403 au and 6.5 vs 5.7 mm, respectively). PVRs were more frequent in the left posterior segments, adjacent to the esophagus, than in other segments (23% vs 10%, respectively). Notably, ILD max was significantly greater in the left posterior segments with acute PVRs with AI min < 297 (median; 6.5 vs 5.1 mm); a similar finding was not observed when with AI min ≥ 297., Conclusion: Smaller ILD may prevent acute PVRs when the AI min is low in the left posterior segments., Competing Interests: The authors declare no conflict of interests for this article. Clinical study IRB approval number/date: 4190‐R/October 3, 2019., (© 2020 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society.)

Introduction: Negative component abolition of the unipolar signal (unipolar signal modification [USM]) reflects the lesion transmurality. The purpose of this study was to compare the procedural safety and outcome between high-power and conventional-power atrial radiofrequency applications during a pulmonary vein isolation (PVI) using USM as a local endpoint., Methods and Results: High-power (50 W) and conventional-power (25-40 W) applications were compared among 120 consecutive patients with paroxysmal atrial fibrillation who underwent a USM-guided PVI. The first 60 patients were treated with conventional-power (CP) group and last 60 with high-power (HP) group. The atrial radiofrequency applications lasted for 5 to 10 seconds (CP group) or 3 to 5 seconds (HP group) after the USM. All procedures were performed using 3D mapping systems with image integration and esophageal temperature monitoring. The baseline characteristics were similar between the two groups. The HP group had fewer acute PV reconnections (62% vs 78%; P = .046) and a reduced procedure time (119.3 ± 28.1 vs 140.1 ± 51.2 minutes; P = .04). Freedom from recurrence after a single ablation procedure without any antiarrhythmic drugs was higher in the HP group than CP group (88.3% vs 73.3% at 12-months after the procedure, log-rank; P = .0423). There were no major complications that required any intervention., Conclusions: The high-power PVI guided by USM decreased the procedural time and may improve the procedural outcomes without compromising the safety., (© 2020 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Background The association between first-degree atrioventricular block (AVB) and life-threatening cardiac events in patients with hypertrophic cardiomyopathy (HCM) remains unclear. This study sought to investigate whether presence of first-degree AVB was associated with HCM-related death in patients with HCM. Methods and Results We included 414 patients with HCM (mean age, 51±16 years; 64.5% men). The P-R interval was measured at the time of the initial evaluation and patients were classified into those with and without first-degree AVB, which was defined as a P-R interval ≥200 ms. HCM-related death was defined as a combined end point of sudden death or potentially lethal arrhythmic events, heart failure-related death, and stroke-related death. First-degree AVB was noted in 96 patients (23.2%) at time of enrollment. Over a median (interquartile range) follow-up period of 8.8 (4.9-12.9) years, a total of 56 patients (13.5%) experienced HCM-related deaths, including 47 (11.4%) with a combined end point of sudden death or potentially lethal arrhythmic events. In a multivariable analysis that included first-degree AVB and risk factors for life-threatening events, first-degree AVB was independently associated with an HCM-related death (adjusted hazard ratio, 2.41; 95% CI, 1.27-4.58; P =0.007), and this trend also persisted for the combined end point of sudden death or potentially lethal arrhythmic events (adjusted hazard ratio, 2.60; 95% CI, 1.28-5.27; P =0.008). Conclusions In this cohort of patients with HCM, first-degree AVB may be associated with HCM-related death, including the combined end point of sudden death or potentially lethal arrhythmic events.

Catheter ablation of atrial fibrillation (AF) is known to facilitate reverse remodeling of the left ventricle. However, factors that can improve the left ventricular (LV) systolic function remain elusive. In this study, we investigated factors related to LV ejection fraction (LVEF) improvement following AF ablation in patients with systolic dysfunction. A total of 140 patients with impaired LVEF (<50%) who underwent AF ablation were retrospectively evaluated. The primary outcome was LVEF improvement. A total of 68, 9, and 15 patients achieved LVEF improvement at 3, 6, and 12 months after AF ablation, respectively. Five patients achieved late LVEF improvement. The overall LVEF improvement rate was 69%. In the receiver operating characteristic curve analysis, the LV end-systolic volume (LVESVI) and early diastolic mitral annular velocity (e') had larger areas under the curve (0.79 and 0.75, respectively) than other echocardiographic parameters, and the most optimal cutoff values of LVESVI and e' were 49.8 ml/m 2 and 5.4 cm/s, respectively. Moreover, preprocedural LVESVI ≤49.8 ml/m 2 and e' ≥5.4 independently predicted the outcome after adjusting for confounders (hazard ratio 1.74; 95% confidence interval 1.06 to 2.95; p = 0.03; hazard ratio, 1.99; 95% confidence interval 1.13 to 3.64; p = 0.01). LVEF improvement was achieved in 69% of patients who underwent AF ablation, including 4% with late improvement. Lower LVESVI and higher e' could independently predict LVEF improvement., (Copyright © 2019. Published by Elsevier Inc.)

Background: A challenging decision exists as whether to abandon or remove noninfectious superfluous leads during lead revisions or cardiac implantable electronic device (CIED) upgrades. There is insufficient data in the Asian population to guide decision making., Methods: This study investigated the safety and efficacy of transvenous lead extractions (TLEs) in a high-volume Japanese center. Among a total of 341 patients who underwent lead revisions or CIED upgrades between 2008 and 2018, 53 patients (16%) who underwent TLEs to remove the superfluous leads were analyzed., Results: Indications for TLE were vascular issues (60%), recalled leads (21%), growth of the body size (6%), abandoned leads in young patients (6%), switch to a subcutaneous implanted cardiac defibrillator (4%), need for an MRI conditional CIED (2%), and risks of vascular injury (2%). The population included 29 patients (55%) with nonfunctional leads and 24 (45%) with functional abandoned leads. A total of 74 target leads (mean 1.4 leads/person, median lead age 6.7 years) were extracted with a complete removal achieved in 98%. All coexisting leads, intended for continued use, were not damaged. All new leads (mean 1.4 leads/person) that had been simultaneously implanted during the TLE procedures were successfully implanted. There was one minor complication (2%) involving a pericardial effusion but it did not affect the hemodynamics., Conclusions: In this Japanese single center experience, the removal of noninfectious superfluous leads with TLEs seemed to be a safe and effective therapeutic option., (© 2019 Wiley Periodicals, Inc.)

Background: Little is known about the acute/long-term outcomes of implantation of cardiac implantable electronic devices (CIED) using a transvenous approach for patients with congenital heart disease (CHD). Methods and Results: We retrospectively investigated the acute/long-term results and complications associated with transvenous CIED implantation in 140 patients with CHD. We implanted 77 pacemakers, 51 implantable cardioverter defibrillators (ICD), and 12 cardiac resynchronization therapy (CRT) devices. Although we successfully implanted pacemakers and ICD in all patients, we could not place a coronary sinus (CS) lead in 25% of the patients requiring CRT devices due to coronary vein anomalies associated with corrected transposition of the great arteries (cTGA). Overall complication rate, lead failure rate, and incidence of device infection were 16%, 9%, and 0.7%, respectively. There was no significant difference in overall complication rates between the simple (n=22) and complex CHD (n=118) groups (14% vs. 16%). The 10-year lead survival for the ICD leads (77%) was significantly lower than for the pacemaker leads (91%, P=0.0065). Conclusions: The outcomes of transvenous CIED in patients with CHD seemed acceptable, although there was a relatively high incidence of complications. CS lead placement for cTGA may be hindered by coronary vein anomalies. Lead survival tended to be lower for ICD than for pacemakers in these patients., Competing Interests: N.H. is a member of Circulation Reports’ Editorial Team. The other authors declare no conflicts of interest., (Copyright © 2019, THE JAPANESE CIRCULATION SOCIETY.)