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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.This retrospective study focused on patients with CRT due to AVB, mild HF at New York Heart Association class II and LVEF50%. A total of 58 patients were divided into two groups: (1) 27 patients with CRT upgrade from RVP40% (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.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, p0.01; from 134.5±36.6 mL to 123.5±45.6 mL in DG, p0.05); 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, p0.01; 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).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.

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 (CFmin), minimum force‐time integral (FTImin), minimum ablation index (AImin), minimum impedance drop (Imp‐min), and maximum inter‐lesion distance (ILDmax), 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 CFmin, FTImin, AImin, and Imp‐min values in the segments other than the SAEs and larger ILDmax values in the SAEs. Furthermore, lower Imp‐min and larger ILDmax 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., In high‐power pulmonary vein isolation, impedance drop has a superiority to predict in‐procedure gap as compared with ablation index.

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).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.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.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).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.

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

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.

A 28-year-old woman with polysplenia was referred to our hospital for atrial lead failure. She had undergone an intracardiac repair (ICR) for incomplete atrioventricular septal defect and the implantation of epicardial pacing leads due to complete atrioventricular block at the age of 1 year. When she was 13 years old, an endocardial dual-chamber pacemaker was implanted via the right subclavian vein because of epicardial lead failure. The contrast-enhanced computed tomography scan revealed an inferior vena cava defect with an azygos vein connection to the superior vena cava, occlusion of the right brachiocephalic vein, a defect of the left brachiocephalic vein, and a persistent left superior vena cava ligated at the ICR. Therefore, lead exchange was indicated. During the operation, the temporary pacing lead and the guidewire for emergent deployment of the Bridge Occlusion Balloon® were advanced through the azygos vein and placed at the right ventricle and the hepatic vein, respectively. Both 11-Fr and 13-Fr mechanical rotational dilator sheaths were needed for the lead extraction owing to dense calcification and tight adhesions. The atrial lead was successfully extracted without any complications despite extremely restricted venous access. A new atrial lead was inserted through the space created by the 13-Fr sheath.

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

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.

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. 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

Background Left ventricular (LV) lead placement at the late activation site (LAS) has been proposed as an optimal LV pacing site (ie, Q-LV interval). However, LAS may be relevant to local electrical conduction, measured as an interval from LV pacing stimulation to QRS onset (S-QRS interval). Objective The purpose of this study was to evaluate the prognostic value of S-QRS for reverse remodeling and the impact of S-QRS on pacing QRS configuration in patients undergoing cardiac resynchronization therapy (CRT). Methods Sixty consecutive heart failure patients with a wide QRS complex underwent CRT. A site with Q-LV ≥95 ms was targeted for LV lead placement. A responder was defined as one with >15% reduction in LV end-systolic volume 6 months after CRT. Results LV lead placement with Q-LV ≥95 ms was achieved in 52 of 60 patients (86.7%). Thirty-two of 52 patients (61.5%) were responders. S-QRS was significantly shorter in responders than nonresponders (P Conclusion In addition to a sufficient Q-LV, S-QRS can be a useful indicator of optimal LV lead position to achieve reverse remodeling. S-QRS contributes to the pacing QRS configuration associated with CRT response.

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.

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.

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 eGFR60 ml/min/1.73 m

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.

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. 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 ventricular tachycardia to normal rhythm.

Funding Acknowledgements None Background Atrial fibrillation (AF) ablation has been known to contribute to a good prognosis in heart failure patients and improve their systolic function. However, the impact of the post-procedural systolic function on the prognosis in them remains unclear. Purpose To investigate the impact of the left ventricular ejection fraction (LVEF) following AF ablation in patients with systolic dysfunction. Methods Out of 1078 consecutive patients who underwent AF ablation including extensive pulmonary vein and superior vena cava isolation, 170 with an impaired pre-procedural LVEF (< 50%) were evaluated. They experienced at least one echocardiographic follow-up within one year after the index procedure. The primary outcome was the composite of all-cause death or heart failure hospitalisations (HFHs). In addition, we categorised the patients into three groups according to the post-procedural LVEF within one year to evaluate the outcome: reduced LVEF (rEF, LVEF < 40%), mid-range EF (mrEF, 40% ≤ LVEF < 50%) and preserved LVEF (pEF, LVEF > 50%). Results After the index procedure, the patients’ LVEF improved with an average increase of 8%, and the post-procedural LVEF consisted of an rEF in 27 (16%), mrEF in 41 (24%), and pEF in 102 (60%) patients. During a median follow-up of 31 months, a total of 22 (13%) patients experienced the composite outcome, including 18 (11%) HFHs and 10 (6%) all-cause deaths (5 with cardiac issues, 2 any malignancies, and 3 other issues). In the Kaplan-Meier analysis using a Bonferroni correction, there was a significant difference in achieving the outcome between the rEF and mrEF, and rEF and pEF, but not between the mrEF and pEF groups (Figure). In a univariate analysis, the hazard ratio of the outcome was shown as follows: an age ≥ 65 years (hazard ratio, HR: 3.4 [95% confidence interval, CI: 1.4–8.5], p = 0.006), history of HFHs for AF (HR: 1.7 [95%CI: 0.7–4.0], p = 0.25), known underlying heart disease (HR: 1.9 [95%CI: 0.8–1.2], p = 0.13), pre-procedural LVEF < 40% (HR: 3.1 [95%CI: 1.3–7.5], p = 0.009), atrial tachyarrhythmia recurrence (HR: 3.0 [95%CI: 1.2–7.8], p = 0.01), and the post-procedural LVEF category (mrEF and rEF, compared with pEF) (HR: 2.0 [95%CI: 0.4–7.7], p = 0.34; and HR: 8.6 [95%CI: 2.7–37.5], p < 0.0001). Furthermore, in a multivariate analysis, patients with a rEF was the sole independent predictor of the composite outcome after adjusting for confounders including an age≥65 years and pre-procedural LVEF < 40% (HR: 12.0 [95%CI: 3.9–40.0], p < 0.0001), whereas those with a mrEF was not (HR: 1.8 [95%CI: 0.4–7.3], p = 0.42), as compared to those with a pEF. Conclusions Patients with a mrEF had a comparable prognosis to those with a pEF in a relatively long follow-up, while those with a rEF had the poorest outcome of the three categories, regardless of the pre-procedural LVEF severity. Abstract Figure. The difference in the rate of outcome

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

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.

Twiddler syndrome is an uncommon complication that occurs by twisting of the generator and may cause torsion, dislodgement, and injury of the leads. We report a rare case of a twiddler syndrome associated with an abdominal permanent pacemaker. Abdominal twiddler syndrome may possess a unique mechanism, which may not be seen in chest twiddler syndrome.

Introduction The guidelines suggest that an adjuvant substrate modification in addition to pulmonary vein isolation (PVI) may be needed for persistent atrial fibrillation (PerAF) assuming that catheter ablation is less successful for PerAF than paroxysmal AF (PAF). To revisit the above assumption, we compared the outcome of the same catheter ablation strategy between PAF and PerAF. Methods and Results Two-hundred and thirty-three consecutive patients (mean age 60±10 years, 53 PerAF and 8 long-lasting PerAF) without structural heart disease underwent catheter ablation of AF by the same strategy using an empiric thoracic vein isolation (a wide circumferential PVI plus empiric superior vena cava isolation) as a major part of the strategy without any adjuvant substrate modification. The duration of AF in the patients with PerAF was 6 ± 4 months. During 25±10 months of follow-up after single procedures, 71 (30%) patients had atrial tachyarrhythmia recurrences without antiarrhythmic drugs. A Kaplan-Meier analysis of the recurrence-free survival rate after a single procedure and after repeat procedures revealed no significant difference between the patients with PAF and those with PerAF (Log-rank, p=0.38 and p=0.27, respectively). A Cox regression multivariate analysis of the variables including the age, gender, PerAF, body mass index, left ventricular ejection fraction, and left atrial volume index demonstrated that none of the variables were an independent predictor of an atrial tachyarrhythmia recurrence after a single ablation procedure. Conclusion In patients without underlying heart disease, the procedural outcome of an empiric thoracic vein isolation is comparable for PAF and PerAF. This article is protected by copyright. All rights reserved

BACKGROUND Tetralogy of Fallot (TOF) is one of the common congenital heart diseases (CHD) in implantable cardioverter defibrillator (ICD) recipients, but few studies have reported the long-term outcomes of and the anti-tachycardia pacing (ATP) efficacy in repaired TOF.Methods and Results:Twenty-one repaired TOF patients with an ICD implanted between April 2003 and March 2015 were investigated retrospectively. ICD therapy and clinical outcome were analyzed. Mean patient age was 39±11 years; 62% were male; and mean age at repair surgery was 9.4±6.8 years. During a median follow-up of 5.6 years (range, 2.6-8.4 years), no patients died. Appropriate ATP were delivered in 11 patients (52%), with appropriate shocks in 5 patients (24%) and inappropriate shocks in 5 patients (24%). The success rate of ATP was 98% for fast ventricular tachycardia (VT; cycle length ≤320 ms) and 98% for slow VT (cycle length >320 ms). ATP effectiveness increased from 81.5% with the first ATP attempt to 93.7% with the second ATP attempt, to 97.5% with the third ATP attempt, and to 98.6% with the fourth or successive ATP attempt (P

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

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.

Studies analyzing optimal voltage thresholds for scar detection with electroanatomic mapping frequently lack a gold standard for comparison.The purpose of this study was to use a porcine infarct model with ex vivo magnetic resonance imaging (MRI) integration to characterize the relationship between interelectrode spacing and bipolar voltage thresholds and examine the influence of 3-dimensional scar on unipolar voltages.Thirty-two combined endocardial-epicardial electroanatomic maps were created in 8 postinfarct porcine subjects (bipolar 2-mm, 5-mm, and 8-mm interelectrode spacing and unipolar) for comparison with ex vivo MRI. Two thresholds were compared: (1) 95% normal distribution and (2) best fit to MRI. Direct electrogram analysis was performed in regions across from MRI-defined scar and adjacent to scar border zone.A linear increase in optimal thresholds was observed with wider bipole spacing. The 95% thresholds for scar were lower than MRI-matched thresholds with moderate sensitivity for nontransmural scar (54% endo, 63% epi). Unipolar endocardial scar area exceeded MRI-defined scar, resulting in mismatched false scar in 5 of 8 (63%). Endocardial and epicardial unipolar voltages were lower than normal in regions adjacent and across from scar.Variations in interelectrode spacing necessitate tailored bipolar voltage thresholds to optimize scar detection. Statistical 95% thresholds appear to be conservative and not fully sensitive for the detection of scar defined by high-resolution ex vivo MRI. In the presence of endocardial scar, unipolar mapping to quantitatively characterize epicardial scar may be overly sensitive due to 3-dimensional spatial averaging.

Introduction Many patients with successful atrial flutter (AFL) ablation will develop atrial fibrillation (AF) during follow-up. This study aimed to determine whether prolonged inter-atrial conduction time (IACT) is associated with risk for new-onset AF after ablation of isolated, typical AFL. Methods Participants were 80 consecutive patients who underwent successful radiofrequency ablation of isolated, typical AFL from 2004 to 2012. Patients with any history of AF prior to AFL ablation were excluded. IACT was defined as the interval from the earliest onset of the P-wave on the ECG to the latest activation in the coronary sinus catheter during sinus rhythm measured after AFL ablation. New-onset AF was identified from 12-lead ECGs, 24-h ambulatory monitoring, and device interrogations. Results During a mean follow-up of 4.1 ± 2.5 years after successful AFL ablation, 22 patients (27.5%) developed new-onset AF. Cox regression multivariate analysis demonstrated that IACT was the independent predictor of new-onset AF after AFL ablation (hazard ratio: 1.03; 95% confidence interval: 1.00-1.06; p = 0.02). IACT was accurate in predicting new-onset AF (AUC = 0.70). The optimal cut-off point of IACT for predicting new-onset AF was 120 ms (sensitivity 47.6%, specificity 89.8%). Kaplan-Meier curves showed that new-onset AF after AFL ablation was significantly higher in patients with IACT ≥120 ms than in patients with IACT< 120 ms (p = 0.0016). Conclusion Prolonged IACT predicted new-onset AF after ablation of isolated AFL. This finding may contribute to guiding decisions regarding the maintenance of anticoagulation after AFL ablation. This article is protected by copyright. All rights reserved

There are some cases that are difficult to cure with only circumferential pulmonary vein isolation (CPVI) of persistent atrial fibrillation (PerAF). Recently, prolonged interatrial conduction times (IACTs), which seem to be associated with progressive remodeled atria, have been reported as a predictor of new-onset AF. This study aimed to investigate the prognostic value of a prolonged IACT for predicting AF recurrences after CPVI of PerAF. One hundred thirteen patients who underwent CPVI without an empirical substrate modification of PerAF were retrospectively analyzed. The IACT was defined as the interval from the earliest P-wave onset on the ECG to the latest activation in the coronary sinus and was measured after achieving the CPVI and conversion to sinus rhythm. During a mean 22.7-month follow-up after the initial procedure, 56 patients (50%) had AF recurrences. Patients with AF recurrence had a longer IACT than those without AF recurrence (p

Atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) patients is highly associated with deterioration of their clinical condition, such as worsening heart failure symptoms, and an increased thromboembolic stroke risk and cardiac mortality rate. This study aimed to investigate the long-term clinical course after catheter ablation (CA) in HCM patients with AF. Among 566 primary HCM patients at our institution, 94 who underwent rhythm control therapy to manage AF from 2002 to 2016 were retrospectively analyzed. The eligible patients were divided into two groups: those who managed AF with CA (n = 34) and those without CA (n = 60). The endpoints were the incidence of initial clinical events, including HCM-related death or an unplanned heart failure hospitalization, or new-onset thromboembolic strokes. During a mean follow-up of 5.8 years, 6% in the CA group and 28% in the non-CA group had a progression of the AF type into permanent AF (Log-rank: p = 0.012). In the Kaplan-Meyer curve analyses, the incidence of clinical events was significantly lower in the CA group than non-CA group (p = 0.025). The annual rates for the incidence of clinical events were 1.2% in the CA group and 6.7% in the non-CA group. In a Cox multivariate analysis, CA therapy (adjusted hazard ratio 0.22; 95% confidence interval: 0.05–0.97; p = 0.046) was the only independent predictor of the incidence of clinical events. In conclusion, CA may be associated with a favorable long-term clinical course in HCM patients with AF.

The recent development of high-density high-spatial resolution three-dimensional mapping has provided detailed information for understanding complicated atrial activation patterns at a level not previously possible. Using this technology, we report a case with recurrent common atrial flutter, demonstrating the presence of a bridging epicardial fiber that traveled across the previous cavotricuspid isthmus ablation lesion with apparent epicardial-endocardial breakthrough (EEB) sites located on both sides of the ablation line. The entrainment study indicated that the EEB site, located adjacent to the coronary sinus ostium, was part of the recurrent circuit and a focal ablation targeting that site terminated the tachycardia.

Vagal nerve stimulation (VNS) has been shown to have antiarrhythmic effects, but many of these benefits were demonstrated in the setting of vagal nerve decentralization. The purpose of this study was to evaluate the role of afferent fiber activation during VNS on efferent control of cardiac hemodynamic and electrophysiological parameters. In 37 pigs a 56-electrode sock was placed over the ventricles to record local activation recovery intervals (ARIs), a surrogate of action potential duration. In 12 of 37 animals atropine was given systemically. Right and left VNS were performed under six conditions: both vagal trunks intact ( n = 25), ipsilateral right ( n = 11), ipsilateral left ( n = 14), contralateral right ( n = 7), contralateral left ( n = 10), and bilateral ( n = 25) vagal nerve transection (VNTx). Unilateral VNTx significantly affected heart rate, PR interval, Tau, and global ARIs. Right VNS after ipsilateral VNTx had augmented effects on hemodynamic parameters and increase in ARI, while subsequent bilateral VNTx did not significantly modify this effect (%change in ARI in intact condition 2.2 ± 0.9% vs. ipsilateral VNTx 5.3 ± 1.7% and bilateral VNTx 5.3 ± 0.8%, P < 0.05). Left VNS after left VNTx tended to increase its effects on hemodynamics and ARI response ( P = 0.07), but only after bilateral VNTx did these changes reach significance (intact 1.1 ± 0.5% vs. ipsilateral VNTx 3.6 ± 0.7% and bilateral VNTx 6.6 ± 1.6%, P < 0.05 vs. intact). Contralateral VNTx did not modify VNS response. The effect of atropine on ventricular ARI was similar to bilateral VNTx. We found that VNS activates afferent fibers in the ipsilateral vagal nerve, which reflexively inhibit cardiac parasympathetic efferent electrophysiological and hemodynamic effects.

BACKGROUND: To evaluate the impact of changes in the filtered QRS duration (fQRS) on signal‐averaged electrocardiograms (SAECGs) from pre‐ to postimplantation on the clinical outcomes in nonischemic heart failure (HF) patients under cardiac resynchronization therapy (CRT). METHODS: We studied 103 patients with nonischemic HF and sinus rhythm who underwent CRT implantation. SAECGs were obtained within 1 week before and 1 week after implantation and narrowing fQRS was defined as a decrease in fQRS from pre‐ to postimplantation. Echocardiography was performed before and 6 months after CRT implantation. The primary outcome was death from any cause. The secondary outcomes were hospitalization due to worsened HF and occurrence of ventricular tachyarrhythmias. RESULTS: Of the 103 CRT patients, 53 (51%) showed narrowing fQRS. Left ventricular end‐diastolic volume and end‐systolic volume were significantly reduced (both p

AimsThe effects of inotropic agents on left ventricular (LV) synchrony in heart failure patients are still unknown. The purpose of this study was to investigate the effects of dobutamine on LV mechanical dyssynchrony and LV systolic performance in patients with dilated cardiomyopathy (DCM) and a narrow QRS using real-time three-dimensional echocardiography (RT3DE).Methods and resultsThirty-three patients with idiopathic DCM and a narrow QRS underwent low-dose dobutamine stress echocardiography (LDSE) with RT3DE. A time-global LV volume curve and time-regional LV volume curves were derived from RT3DE. Regional LV stroke volumes were summed in each stage, and the dobutamine-induced increase in the sum of regional LV stroke volumes was considered as the sum of regional contractile reserve. Systolic dyssynchrony index (SDI) was calculated as follows: (standard deviation of time to minimal volume for regional LV segments)×100/RR duration. Among the 33 patients, low-dose dobutamine increased global LV stroke volume (SV) in 28 (85%), but decreased global LVSV in the remainder (15%). The sum of regional contractile reserve was modestly correlated with the dobutamine-induced increase in global LVSV (R=0.57, p

Objective To evaluate the impact of diastolic dysfunction on the outcome of atrial fibrillation (AF) ablation. Methods Eighty consecutive patients with drug-refractory symptomatic AF who underwent AF ablation were enrolled (65 males, 58±10years, 65 paroxysmal AF, 15 persistent AF). All patients underwent extensive pulmonary vein isolation with a double lasso technique using CARTO MERGE. Diastolic dysfunction was defined as a ratio of the mitral inflow early filling velocity to the velocity of the early medial mitral annular ascent of >10. The clinical and echocardiographic data were compared between the patients with and without diastolic dysfunction, and between the patients with and without AF recurrences after the AF ablation. Results Twenty-nine out of all the patients (36.3%) had diastolic dysfunction. Compared with the patients without diastolic dysfunction, the patients with diastolic dysfunction had higher brain natriuretic peptide (p=0.001) and C-reactive protein (p=0.023) levels, and a larger left atrial diameter (P=0.019). The AF-free rate after a single or repeat AF ablation procedure in the patients with diastolic dysfunction was lower than that in those without diastolic dysfunction (p=0.005 and p=0.013 by the log-rank test, respectively). In the univariate analysis, the patients with persistent AF and diastolic dysfunction were likely to have AF recurrences after a single AF ablation. The multivariate analysis indicated diastolic dysfunction as the only independent predictor of an AF recurrence after a single AF ablation (P=0.023). Conclusion The patients with diastolic dysfunction had a worse outcome of the AF ablation not only for a single procedure but also a repeat procedure.

Summary Objectives The purpose of this study was to explore the possibility of using our novel echocardiographic index of inefficient left ventricular (LV) contraction in patient selection for cardiac resynchronization therapy (CRT). Methods Forty consecutive patients with LV ejection fraction ≤35% were divided into 2 groups, 9 CRT candidates and 31 non-CRT candidates based on conventional criteria. A global LV time–area curve and regional LV time–area curves in 6 radial sectors were obtained using two-dimensional echocardiography in the short-axis view with speckle tracking. Fractional inefficient contraction (FIC, %) was calculated as follows: (1 − global LV area change/sum of regional LV area changes) × 100. LV dyssynergy and dyssynchrony were quantified as the standard deviations of minimal values of circumferential speckle-tracking strain and their timings in the 6 sectors, respectively. Results There was no significant difference in LV dyssynchrony between CRT candidates and non-CRT candidates (79 ± 61 ms vs. 58 ± 26 ms, respectively). In contrast, FIC was significantly larger in CRT candidates than in non-CRT candidates (15.7 ± 11.0% vs. 5.4 ± 3.5%, respectively, p = 0.0018), with less overlap between groups. FIC showed a positive correlation with dyssynchrony (r = 0.64) and a negative correlation with dyssynergy (r = −0.42). Conclusions Our novel echocardiographic index of inefficient LV contraction, which increases with more dyssynchrony or less dyssynergy, may prove more useful in patient selection for CRT than other indices that focus on LV temporal dyssynchrony alone.

Aims To evaluate the feasibility of integrating three-dimensional images created by intra-procedural cone-beam computed tomography (CBCT) into three-dimensional electroanatomical maps (EAM) and compare its accuracy with that of pre-procedural multi-slice CT (MSCT). Methods and results In 24 patients with drug-refractory atrial fibrillation (AF), atriography using CBCT with pulmonary arterial contrast injection was performed at the beginning of the AF ablation procedure. Intra-procedural CBCT images and pre-procedural MSCT images were individually imported into the EAM system and compared their integration accuracy (point-to-surface distance) of each image and EAM just before ablation. The CBCT images were assessed qualitatively and quantitatively in comparison with MSCT images. All CBCT images were graded as optimal or useful in delineating the left atrium–pulmonary vein anatomy and were successfully integrated with the EAM. Overall, integration accuracy was similar for CBCT and MSCT. However, in 11 patients, the MSCT was performed 5 or more days prior to EAM, resulting in significantly shorter surface-to-point distance in CBCT than that in MSCT ( P = 0.047). Radiation exposure with CBCT was significantly reduced compared with MSCT ( P < 0.001). Conclusion It is feasible to integrate CBCT image into EAM, and the integration is relatively accurate. Intra-procedural atriography by CBCT may replace pre-procedural MSCT as the imaging source for image integration.

Sympathoexcitation is associated with ventricular arrhythmogenesis. The aim of this study was to determine the role of thoracic dorsal root afferent neural inputs to the spinal cord in modulating ventricular sympathetic control of normal heart electrophysiology. We hypothesize that dorsal root afferent input tonically modulates basal and evoked efferent sympathetic control of the heart. A 56-electrode sock placed on the epicardial ventricle in anesthetized Yorkshire pigs ( n = 17) recorded electrophysiological function, as well as activation recovery interval (ARI) and dispersion in ARI, at baseline conditions and during stellate ganglion electrical stimulation. Measures were compared between intact states and sequential unilateral T1–T4 dorsal root transection (DRTx), ipsilateral ventral root transection (VRTx), and contralateral dorsal and ventral root transections (DVRTx). Left or right DRTx decreased global basal ARI [Lt.DRTx: 369 ± 12 to 319 ± 13 ms ( P < 0.01) and Rt.DRTx: 388 ± 19 to 356 ± 15 ms ( P < 0.01)]. Subsequent unilateral VRTx followed by contralateral DRx+VRTx induced no further change. In intact states, left and right stellate ganglion stimulation shortened ARIs (6 ± 2% vs. 17 ± 3%), while increasing dispersion (+139% vs. +88%). There was no difference in magnitude of ARI or dispersion change with stellate stimulation following spinal root transections. Interruption of thoracic spinal afferent signaling results in enhanced basal cardiac sympathoexcitability without diminishing the sympathetic response to stellate ganglion stimulation. This suggests spinal dorsal root transection releases spinal cord-mediated tonic inhibitory control of efferent sympathetic tone, while maintaining intrathoracic cardiocentric neural networks.

The safety and efficacy of an empiric superior vena cava isolation (SVCI) in addition to circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (PAF) have not been clarified. A total of 186 consecutive patients who underwent catheter ablation of PAF were included. All patients underwent a CPVI. Patients in the first half underwent an additional SVCI only if SVC-triggered AF or rapid SVC activity was observed during the procedure (n = 93, as-needed SVCI, group I), and those in the second half underwent an empirical SVCI after the CPVI (n = 93, empiric SVCI, group II). The CPVI was successfully performed in all patients. An SVCI was performed in 8 of 93 patients (9%) in group I and 81 of the 93 patients (87%) in group II. In the remaining 12 patients in group II, an SVCI was not performed because of the lack of SVC potentials. During a mean follow-up of 27 ± 12 months, the atrial tachyarrhythmia recurrence rate after a single ablation procedure in the patients in group II was lower than that in group I (44% vs 23%, p = 0.035). A Cox regression multivariate analysis demonstrated that an empiric SVCI was an independent predictor of an atrial tachyarrhythmia recurrence after a single ablation procedure (odds ratio: 0.57, 95% confidence interval 0.31 to 0.999; p = 0.049). Neither sinus node injury nor any injury to the phrenic nerve was observed. In conclusion, an empiric SVCI in addition to the CPVI improved the outcome of AF ablation in patients with PAF without any additional adverse effects.

Background Myocardial infarction (MI) induces remodeling in stellate ganglion neurons (SGNs). Objective We investigated whether infarct site has any impact on the laterality of morphologic changes or neuropeptide expression in stellate ganglia. Methods Yorkshire pigs underwent left circumflex coronary artery (LCX; n=6) or right coronary artery (RCA; n=6) occlusion to create left- and right-sided MI, respectively (control: n=10). At 5 ± 1 weeks after MI, left and right stellate ganglia (LSG and RSG, respectively) were collected to determine neuronal size, as well as tyrosine hydroxylase (TH) and neuropeptide Y immunoreactivity. Results Compared with control, LCX and RCA MIs increased mean neuronal size in the LSG (451 ± 25 vs 650 ± 34 vs 577 ± 55 μm 2 , respectively; P = .0012) and RSG (433 ± 22 vs 646 ± 42 vs 530 ± 41 μm 2 , respectively; P = .002). TH immunoreactivity was present in the majority of SGNs. Both LCX and RCA MIs were associated with significant decreases in the percentage of TH-negative SGNs, from 2.58% ± 0.2% in controls to 1.26% ± 0.3% and 0.7% ± 0.3% in animals with LCX and RCA MI, respectively, for LSG ( P = .001) and from 3.02% ± 0.4% in controls to 1.36% ± 0.3% and 0.68% ± 0.2% in LCX and RCA MI, respectively, for RSG ( P = .002). Both TH-negative and TH-positive neurons increased in size after LCX and RCA MI. Neuropeptide Y immunoreactivity was also increased significantly by LCX and RCA MI in both ganglia. Conclusion Left- and right-sided MIs equally induced morphologic and neurochemical changes in LSG and RSG neurons, independent of infarct site. These data indicate that afferent signals transduced after MI result in bilateral changes and provide a rationale for bilateral interventions targeting the sympathetic chain for arrhythmia modulation.

Background— T-peak to T-end interval (Tp-e) is an independent marker of sudden cardiac death. Modulation of Tp-e by sympathetic nerve activation and circulating norepinephrine is not well understood. The purpose of this study was to characterize endocardial and epicardial dispersion of repolarization (DOR) and its effects on Tp-e with sympathetic activation. Methods and Results— In Yorkshire pigs (n=13), a sternotomy was performed and the heart and bilateral stellate ganglia were exposed. A 56-electrode sock and 64-electrode basket catheter were placed around the epicardium and in the left ventricle (LV), respectively. Activation recovery interval, DOR, defined as variance in repolarization time, and Tp-e were assessed before and after left, right, and bilateral stellate ganglia stimulation and norepinephrine infusion. LV endocardial and epicardial activation recovery intervals significantly decreased, and LV endocardial and epicardial DOR increased during sympathetic nerve stimulation. There were no LV epicardial versus endocardial differences in activation recovery interval during sympathetic stimulation, and regional endocardial activation recovery interval patterns were similar to the epicardium. Tp-e prolonged during left (from 40.4±2.2 ms to 92.4±12.4 ms; P P P P R =0.86). Of note, norepinephrine infusion did not increase DOR or Tp-e. Conclusions— Regional patterns of LV endocardial sympathetic innervation are similar to that of LV epicardium. Tp-e correlated with whole heart DOR during sympathetic nerve activation. Circulating norepinephrine did not affect DOR or Tp-e.

Myocardial infarction (MI) induces neural and electrical remodeling at scar border zones. The impact of focal MI on global functional neural remodeling is not well understood. Sympathetic stimulation was performed in swine with anteroapical infarcts (MI; n = 9) and control swine ( n = 9). A 56-electrode sock was placed over both ventricles to record electrograms at baseline and during left, right, and bilateral stellate ganglion stimulation. Activation recovery intervals (ARIs) were measured from electrograms. Global and regional ARI shortening, dispersion of repolarization, and activation propagation were assessed before and during sympathetic stimulation. At baseline, mean ARI was shorter in MI hearts than control hearts (365 ± 8 vs. 436 ± 9 ms, P < 0.0001), dispersion of repolarization was greater in MI versus control hearts (734 ± 123 vs. 362 ± 32 ms2, P = 0.02), and the infarcted region in MI hearts showed longer ARIs than noninfarcted regions (406 ± 14 vs. 365 ± 8 ms, P = 0.027). In control animals, percent ARI shortening was greater on anterior than posterior walls during right stellate ganglion stimulation ( P = 0.0001), whereas left stellate ganglion stimulation showed the reverse ( P = 0.0003). In infarcted animals, this pattern was completely lost. In 50% of the animals studied, sympathetic stimulation, compared with baseline, significantly altered the direction of activation propagation emanating from the intramyocardial scar during pacing. In conclusion, focal distal anterior MI alters regional and global pattern of sympathetic innervation, resulting in shorter ARIs in infarcted hearts, greater repolarization dispersion, and altered activation propagation. These conditions may underlie the mechanisms by which arrhythmias are initiated when sympathetic tone is enhanced.

Background— Radiofrequency ablation for ventricular tachycardia is an established therapy. Use of chemical agents for scar homogenization represents an alternative approach. The purpose of this study was to characterize the efficacy of collagenase (CLG) application on epicardial ventricular scar homogenization. Methods and Results— Myocardial infarcts were created in Yorkshire pigs (n=6) by intracoronary microsphere injection. After 46.6±4.3 days, CLG type 2, type 4, and purified CLG were applied in vitro (n=1) to myocardial tissue blocks containing normal myocardium, border zone, and dense scar. Histopathologic studies were performed to identify the optimal CLG subtype. In vivo high-density electroanatomic mapping of the epicardium was also performed, and border zone and dense scar surface area and late potentials were quantified before and after CLG-4 application (n=5). Of the CLG subtypes tested in vitro, CLG-4 provided the best scar modification and least damage to normal myocardium. During in vivo testing, CLG-4 application decreased border zone area (21.3±14.3 to 17.1±11.1 mm 2 , P =0.043) and increased dense scar area (9.1±10.3 to 22.0±20.6 mm 2 , P =0.043). The total scar area before and after CLG application was 30.4±23.4 and 39.2±29.5 mm 2 , respectively ( P =0.08). Late potentials were reduced by CLG-4 application (28.8±21.8 to 13.8±13.1, P =0.043). During CLG-4 application (50.0±15.5 minutes), systolic blood pressure and heart rate were not significantly changed (68.0±7.7 versus 61.8±5.3 mmHg, P =0.08; 77.4±7.3 versus 78.8±6.0 beats per minute, P =0.50, respectively). Conclusions— Ventricular epicardial scar homogenization by CLG-4 application is feasible and effective. This represents the first report on bioenzymatic ablation of arrhythmogenic tissue as an alternative strategy for lesion formation.