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Background While advances in the characterization of the structural substrate in arrhythmogenic right ventricular cardiomyopathy (ARVC) have been made, the ventricular tachycardia (VT) circuit remains incompletely described. Objective The purpose of this study was to delineate the reentrant VT circuit with simultaneous epicardial and endocardial mapping (SEEM) in ARVC. Methods Twenty-three consecutive patients with ARVC and VT underwent SEEM at 4 centers between 2014 and 2020. Retrospective analysis was performed on combined isochronal activation maps. Results Of the 30 VT circuits, 24 were delineated with SEEM (956 [341–1843] endocardial points and 1763 [882–3054] epicardial points). The apex and outflow tract rarely harbored VT circuits, with 50% distributed in the inferior wall and 43% in the free wall. The entire tachycardia cycle length was recorded from the epicardium in 71% of circuits. In all circuits, a large proportion of the tachycardia cycle length was recorded from the epicardium relative to the endocardium. Localized epicardial reentry was observed in 35% of patients (14 mm × 15 mm), which was associated with smaller endocardial low voltage area (39 cm2 vs 104 cm2; P = .002) and preserved right ventricular ejection fraction (35% vs 25%; P = .046) compared with those with larger circuit dimensions. Seventy percent of termination sites were achieved from the epicardium. Conclusion High-resolution recordings from both myocardial surfaces confirm a consistent predominance of epicardial participation during reentry in ARVC. Only the perivalvular inflow region of the “triangle of dysplasia” had a strong propensity to harbor VT circuits, with the greatest proportion located in the inferior wall. Localized epicardial reentry may be a manifestation of earlier stage disease with a relative paucity of endocardial substrate.

We present a case of wide-complex tachycardia in which the clinical electrophysiological diagnosis was considered to be bundle branch re-entry ventricular tachycardia. A series of ventricular entrainment attempts were performed from the left and right ventricular septum to confirm the diagnosis. Entrainment pacing with a general current output (10 mA) was performed from the right ventricular septum with manifest fusion and a post-pacing interval similar to tachycardia cycle length. Thereafter, another entrainment attempt with a greater current output (20 mA) was performed from the same site. Paradoxically, concealed fusion was demonstrated by selective RB capture only, though there was no clear "RB" potential seen. In this case, we attempt to explain and illustrate the mechanism of paradoxical near-field inability to capture with increasing current strength.

Mechanisms of scar-related ventricular tachycardia (VT) are largely based on computational and animal models that portray a 2-dimensional view.The authors sought to delineate the human VT circuit with a 3-dimensional perspective from recordings obtained by simultaneous endocardial and epicardial mapping.High-resolution mapping was performed during 97 procedures in 89 patients with structural heart disease. Circuits were characterized by systematic isochronal analysis to estimate the dimensions of the isthmus and extent of the exit region recorded on both myocardial surfaces.A total of 151 VT morphologies were mapped, of which 83 underwent simultaneous endocardial and epicardial mapping; 17% of circuits activated in a 2-dimensional plane, restricted to 1 myocardial surface. Three-dimensional activation patterns with nonuniform transmural propagation were observed in 61% of circuits with only 4% showing transmurally uniform activation, and 18% exhibiting focal activation patterns consistent with mid-myocardial reentry. The dimensions of the central isthmus were 17 mm (12 to 28 mm) × 10 mm (9 to 19 mm) with 55% exhibiting a minimal dimension of 1.5 cm. QRS activation was transmural in 63% and located 43 mm (34 to 52 mm) from the central isthmus. On the basis of 6 proposed definitions for epicardial VT, the prevalence of an epicardial circuit ranged from 21% to 80% in ischemic cardiomyopathy and 28% to 77% in nonischemic cardiomyopathy.A 2D perspective oversimplifies the electrophysiological circuit responsible for reentrant human VT and simultaneous endocardial and epicardial mapping facilitates inferences about mid-myocardial activation. Intricate activation patterns are frequently observed on both myocardial surfaces, and the epicardium is functionally involved in the majority of circuits. Human reentry may exist within isthmus dimensions smaller than 1 cm, whereas QRS activation is often transmural and remote from the critical isthmus target. A 3-dimensional perspective of the VT circuit may enhance the precision of ablative therapy and may support a greater role for adjunctive strategies and technology to address arrhythmogenic tissue harbored in the mid-myocardium and subepicardium.

Objective: The purpose of this study was to evaluate the difference in effectiveness and safety of high-power, short-duration (HPSD) radiofrequency catheter ablation (RFA) guided by relatively low ablation index (AI) values and conventional RFA in paroxysmal atrial fibrillation (PAF) patients. Methods: The HPSD RFA strategy (40–50 W, AI 350–400 for anterior, 320–350 for posterior wall; n = 547) was compared with the conventional RFA strategy (25–40 W, without AI; n = 396) in PAF patients who underwent their first ablation. Propensity-score matching analyses were used to compare the outcomes of the two groups while controlling for confounders. Results: After using propensity-score matching analysis, the HPSD group showed a higher early recurrence rate (22.727% vs. 13.636%, p = 0.003), similar late recurrence rate, and comparable safety (p = 0.604) compared with the conventional group. For late recurrent atrial arrhythmia types, the rate of regular atrial tachycardia was significantly higher in the HPSD group (p = 0.013). Additionally, the rate of chronic pulmonary vein reconnection and non-pulmonary vein triggers during repeat procedures was similar in both groups. Conclusions: For PAF patients, compared with the conventional RFA strategy, the HPSD RFA strategy at relatively low AI settings had a higher early recurrence rate, similar long-term success rate, and comparable safety.

BackgroundCatheter ablation target at the site with large His activation in the left ventricle poses a high risk of atrioventricular (AV) block. We aimed to identify far-field (FF) and near-field (NF) His activation at left upper septum (LUS).MethodsThree-D mapping of the aortic root and left ventricle was performed in 12 dogs. Two sites located at either the base or apex of the triangle interposed between the hinges of the the noncornary coronary cusp (NCC) - right coronary cusp (RCC) were chosen for a single radiofrequency (RF) application. Bipolar and unipolar pacing with different outputs at both sites was attempted to discern NF and FF His activation.ResultsThe sites chosen for NF and FF ablation were located at the base and apex of the triangle, which were 8.03 ± 1.18 mm (group 1) and 3.42 ± 0.61 mm (group 2) away from the RCC-NCC junction. Lower A/V ratios were found in group 1. Pacing could not differentiate NF from FF His activation. In group 1, ablation resulted in III degree AV block in all 6 dogs, whereas neither PR prolongation nor AV block occurred in group 2. Pathologic examination of group 1 showed complete/partial necrosis of the His bundle (HB) and left bundle branch in all 6 dogs. In group 2, no necrosis of the HB was seen in the 6/6 dogs.ConclusionAnatomical localization in the triangle of RCC-NCC junction can help differentiate NF from FF His activation.

Objective: Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. About half of sudden deaths from AMI are mainly because of malignant ventricular arrhythmias (VA) after AMI. The sodium channel gene SCN5A and potassium channel genes KCNQ1 and KCNH2 have been widely reported to be genetic risk factors for arrhythmia including Brugada syndrome and long QT syndrome (LQTS). A few studies reported the association of SCN5A variant with ventricular tachycardia (VT)/ventricular fibrillation (VF) complicating AMI. However, little is known about the role of KCNQ1 and KCNH2 in AMI with VA (AMI_VA). This study focuses on investigating the potential variants on SCN5A, KCNQ1, and KCNH2 contributing to AMI with VA in a Chinese population. Materials and Methods: In total, 139 patients with AMI_VA, and 337 patients with AMI only, were included. Thirty exonic sites were selected to be screened. Sanger sequencing was used to detect variants. A subsequent association study was also performed between AMI_VA and AMI. Results: Twelve variants [5 on KCNH2(NM_000238.3), 3 on KCNQ1(NM_000218.2), and 4 on SCN5A(NM_198056.2)] were identified in AMI_VA patients. Only 5 (KCNH2: c.2690A>C; KCNQ1: c.1927G>A, c.1343delC; SCN5A: c.1673A>G, c.3578G>A) of them are missense variants. Two (KCNQ1: c.1343delC and SCN5A: c.3578G>A) of the missense variants were predicted to be clinically pathogenic. All these variants were further genotyped in an AMI without VA group. The association study identified a statistically significant difference in genotype frequency of KCNH2: c.1539C>T and KCNH2: c.1467C>T between the AMI and AMI_VA groups. Moreover, 2 rare variants (KCNQ1: c.1944C>T and SCN5A: c.3621C>T) showed an elevated allelic frequency (more than 1.5-fold) in the AMI_VA group when compared to the AMI group. Conclusion: Twelve variants (predicting from benign/VUS to pathogenic) were identified on KCNH2, KCNQ1, and SCN5A in patients with AMI_VA. Genotype frequency comparison between AMI_VA and AMI identified 2 significant common variants on KCNH2. Meanwhile, the allelic frequency of 2 rare variants on KCNQ1 and SCN5A, respectively, were identified to be enriched in AMI_VA, although there was no statistical significance. The present study suggests that the ion-channel genes KCNH2, KCNQ1, and SCN5A may contribute to the pathogenesis of VA during AMI.

Background To estimate the prevalence of elevated blood glucose level (EBG, including type 2 diabetes mellitus and impaired fasting glucose), and its association with non-valvular atrial fibrillation (NVAF) in Guangzhou, China. Methods The population-based follow-up Guangzhou Heart Study collected baseline data from July 2015 to August 2017 among 12,013 permanent residents aged > 35 from 4 Guangzhou districts. Two streets (Dadong and Baiyun) in the Yuexiu District, and one street (Xiaoguwei) and two towns (Xinzao and Nancun) in the Panyu District were chosen as representative of urban and rural areas, respectively. Each participant completed a comprehensive questionnaire, and underwent physical examination, blood sample collection for laboratory testing, electrocardiography, and other evaluations. Multivariable logistic regression analyses were used to estimate the independent association between hyperglycemia and NVAF prevalence. Results The prevalence of EBG in overall study population was 29.9%. Compared with residents without EBG, the odds ratio (OR) for AF among residents with EBG was significantly higher (1.94, 95% confidence interval [CI]: 1.40–2.70, P P = 0.007), and driven by women (OR = 1.80, 95% CI: 1.12–2.91, P = 0.016). Conclusions In Guangzhou, China, prevalence of EBG is high among residents aged > 35 years and associated with a multivariate adjusted increase in prevalence of NVAF overall and in women.

Background: To explore an effective, reproducible and less invasive surgical approach for lone atrial fibrillation (AF). Methods: A modified “mini-maze” including pulmonary vein isolation (PVI), box-lesion and left atrial appendage (LAA) resection was applied for AF patients in our center from January 2016 to June 2017. A 2.5 cm thoracotomy extended with tissue retractor was made as working port in the fourth intercostal space on each anterior side of the chest. The thoracoscope was inserted in another port lateral to main port for observing. During PVI, the tip of the clamp could be adjusted to reach as superior as the roof of left atrium for transmural lesions. The floor line was made by linear ablation pen. The LAA was removed by stapler before PVI for better exposure of the roof. Results: This modified “mini-maze” was successfully completed in 53 non-paroxysmal AF patients except 1 was converted to sternotomy due to intraoperative hemorrhage. All patients recovered uneventfully. Seven-day Holter was accessed in 3, 6 and 12 months respectively in all patients. The mean follow-up was 14 (range, 3–30) months. Sinus rhythm was achieved in 48.1%, 64.8% before discharge and 3 months after surgery respectively, Twenty-eight patients in sinus rhythm or not, underwent catheter mapping and ablation three months after the operation to conform the lesion set made by this procedure. Sinus rhythm reached 87.0% after subsequent catheter ablation without any anti-arrhythmia treatment at 12 months. All patients survived without stroke, hemorrhage and pulmonary vein stenosis. Conclusions: Modified “mini-maze” procedure is safe, less invasive and highly reproducible for lone AF. Sequential hybrid procedure will shape the treatment of non-paroxysmal AF.

The role of catheter ablation as an adjunct and alternative to ICD implantation is not known in patients at risk for recurrent ventricular tachycardia (VT) and sudden cardiac death (SCD) across Asia. Patients with nonischemic etiologies of cardiomyopathy, which are highly prevalent in Asia, have not been previously enrolled in randomized trials of VT ablation. To evaluate whether preemptive catheter ablation in patients with monomorphic VT and an indication for ICD implantation results in improved clinical outcomes compared to ICD implantation with standard medical therapy alone. To examine the natural history of ablation outcomes in the absence of background ICD therapy in patients that refuse randomization. The PAUSE-SCD study (NCT02848781) is a prospective, multi-center, randomized controlled trial enrolling patients with structural heart disease (EF

Aims Inadvertent puncture of the aortic root (AR) is a well-known complication of transseptal puncture (TSP). Strategies for handling of this potentially lethal complication have not been identified yet. In this study, we present typical anatomical locations and clinical management of aortic root puncture (ARP) due to TSP. Methods and results All patients with ARP were retrospectively collected from seven hospitals. Aortic root puncture was identified and classified regarding angiographical and intraoperative findings in cardiac surgery: (i) TSP from the right atrium (RA) to the non-coronary sinus (NCS), (ii) TSP from RA to the non-coronary sinutubular junction (STJ), and (iii) TSP from RA to the ascending aorta (AA). A total of 24 patients with inadvertent ARP were identified. In 19 patients, penetration of the aorta was accomplished by the inner dilator, in 5 patients by the complete sheath. Previous cardiac surgery had been performed in six patients. There were 13 RA-to-NCS punctures, 2 RA-to-STJ punctures, and 9 RA-to-AA punctures. No cardiac tamponade (CT) occurred in patients with RA-to-NCS and RA-to-STJ punctures. In 8 of 9 patients with RA-to-AA puncture, CT occurred immediately requiring urgent pericardiocentesis and surgical repair. Two patients died after surgical repair. In the 16 patients without surgical therapy, no shunt from the AR to the RA was observed 3 months after the procedure. Conclusion Aortic root puncture due to mislead TSP via NCS or STJ is usually not associated with a severe clinical course while ARP into the AA via the epicardial space generally leads to CT requiring surgical repair.

Background Ablation of para-Hisian ventricular arrhythmias (PH-VAs) is challenging because of the close relationship of the origin site and His bundle. Using pacing techniques to differentiate the near-field from far-field His activations, thereby avoiding atrioventricular block, has been reported in patients with para-Hisian accessory pathways. Objectives We applied the same pacing technique and 3-dimensional mapping to guide radiofrequency (RF) ablation in patients with right-sided PH-VAs and investigated the clinical outcome of such cases. Methods Fourteen patients with right-sided PH-VAs were included in this study. The earliest activation sites were confirmed in the right ventricle on the 3-dimensional map. Pacing with different outputs was performed at the largest His potential site (P1) and the earliest activation site (P2). If the minimum His bundle-right bundle branch–captured output at P2 was higher than that at P1, RF ablation was performed at the site. Results All the patients in this study had monomorphic premature ventricular contractions (PVCs) with a mean QRS duration of 118.3 ± 8.1 ms. A His-right bundle branch potential with an amplitude of 0.05 ± 0.02 mV was recorded at P2, with a mean distance of 5.97 ± 1.84 mm away from P1. PVCs were successfully eliminated in 13 of 14 patients (92.9%). One patient exhibited persistent right bundle branch block after ablation, and 1 recurrence of ablated PVCs occurred during a median follow-up period of 15 months. Conclusion Using a simple pacing technique to evaluate the safety of RF energy application led to a high success rate of RF catheter ablation of right-sided PH-VAs without atrioventricular block.

The incidence of atrial tachycardia (AT) after rheumatic mitral valvular (RMV) surgery has been well described. However, there have been few reports on the characteristics, mechanism, and long-term ablation outcome of ATs after RMV surgery and concomitant Cox-MAZE IV procedure.The present study reviewed consecutive patients who underwent AT ablation between May 2008 and July 2013. All patients were refractory to antiarrhythmic drugs (AADs) and had a history of RMV surgery and Cox-MAZE IV procedure. A total of 34 patients underwent AT ablation after RMV surgery and concomitant Cox-MAZE IV procedure, and presented 57 mappable and 2 unmappable ATs. The 57 mappable ATs included 14 focal-ATs and 43 reentry-ATs. Ten of the 14 focal-like ATs were located at the pulmonary vein (PV) antrum and border of a box lesion. Of the 43 reentry-ATs, 16 were marco-reentrant around the mitral annulus (MA) and 16 around the tricuspid annulus. There were 41 atypical ATs (non-cavotricuspid isthmus related) including 16 ATs related to the box lesion and 21 ATs related to other Cox-MAZE IV lesions. The AT were successfully terminated in 33 (97.1%) patients. After mean follow-up of 46.9 ± 15.7 months, 25 (73.5%) patients maintained sinus rhythm without AADs after a single procedure and 28 (82.4%) patients after repeated procedures.The recurrent ATs after RMV surgery and concomitant Cox-MAZE IV were mainly reentry mechanism, and largely related to LA. An incomplete lesion or re-conductive gaps in a prior lesion might be the predominant mechanisms for these ATs. Catheter-based mapping and ablation of these ATs seems to be effective and safe during a long-term follow-up.

Objectives This study sought to determine the long-term outcomes of catheter ablation (CA) of ventricular tachycardia (VT) in a series of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) without background implantable cardioverter-defibrillator (ICD) therapy. Background Endo-epicardial CA of VT has been demonstrated to be highly effective in reducing recurrent VT in patients with ARVC. Methods Thirty-two patients (age 45 ± 13 years, 72% male) with ARVC and VT underwent CA in the absence of ICD therapy. ICD was recommended in all cases, but implantation was not performed due to patient refusal (63%) or financial hardship (37%). CA was guided by activation/entrainment mapping for mappable VT and pace mapping/targeting of abnormal substrate in cases of unmappable VT. Results Symptoms associated with clinical VT included palpitations (78%), chest pain and shortness of breath (22%), pre-syncope (16%), and syncope (13%). Prior to ablation, 22 patients (69%) failed a mean of 1.3 ± 0.5 antiarrhythmic drugs. Epicardial mapping and ablation was performed as first-line strategy (20 [63%]) or in case of recurrent VT or persistent inducibility after endocardial-only ablation (3 [9%]—surgical epicardial cryoablation in 1 patient). After a mean of 1.6 (range 1 to 3) procedures, all patients demonstrated noninducibility of sustained VT from at least 2 RV sites; 75% also had stimulation on isoproterenol with no inducible VT. At a median follow-up of 46 months (range 26 to 65 months) following the last ablation, no deaths were observed and freedom from recurrent VT was 81%. Conclusions In this multicenter international registry of patients with ARVC and VT, CA performed in the absence of background ICD was associated with a low rate of symptomatic VT recurrence (19%) without mortality during 46-month median follow-up. These data suggest that further prospective studies may refine selection of patients with structural heart disease at low risk for SCD, possibly obviating the benefit of ICD therapy.

Background: The feasibility and safety of left bundle branch pacing (LBBP) in patients with conduction diseases following prosthetic valves (PVs) have not been well described.Methods: Permanent LBBP was attempted in patients with PVs. Procedural success and intracardiac electrical measurements were recorded at implant. Pacing threshold, complications, and echocardiographic data were assessed at implant and follow-up visit.Results: Twenty-two consecutive patients with atrioventricular (AV) conduction disturbances (10 with AV nodal block and 12 with infranodal block) underwent LBBP. The PVs included aortic valve replacement (AVR) in six patients, mitral valve repair or replacement (MVR) with tricuspid valve ring (TVR) in four patients, AVR with TVR in one patient, AVR with MVR plus TVR in three patients, transcatheter aortic valve replacement (TAVR) in five patients, and MVR alone in three patients. LBBP succeeded in 20 of 22 (90.9%) patients. LBB potential was observed in 15 of 22 (68.2%) patients, including 10 of 15 (66.7%) patients with AVR/TAVR and five of seven (71.4%) patients without AVR/TAVR. AVR and TVR served as good anatomic landmarks for facilitating the LBBP. The final sites of LBBP were 17.9 ± 1.4 mm inferior to the AVR and 23.0 ± 3.2 mm distal and septal to the TVR. The paced QRS duration was 124.5 ± 13.8 ms, while the baseline QRS duration was 120.0 ± 32.5 ms (P = 0.346). Pacing threshold and R-wave amplitude at implant were 0.60 ± 0.16 V at 0.5 ms and 11.9 ± 5.5 mV and remained stable at the mean follow-up of 16.1 ± 10.8 months. No significant exacerbation of tricuspid valve regurgitation was observed compared to baseline.Conclusion: Permanent LBBP could be feasibly and safely obtained in the majority of patients with PVs. The location of the PV might serve as a landmark for guiding the final site of the LBBP. Stable pacing parameters were observed during the follow-up.

Objectives This study aimed to investigate the prevalence of congenital heart disease (CHD) among school children in Qinghai province, a high-altitude region in China. Methods A cross-sectional study was conducted among school-aged children in 2019. All subjects completed a survey with a structure questionnaire and underwent CHD screening. CHD was screened by standard physical examination and further confirmed by echocardiography. Multivariate logistic regression were used to estimate the association of CHD prevalence with gender, nationality, and altitude. Results A total of 43,562 children aged 3–19 years participated in the study. The mean (SD) age was 11.2 (3.3) years. 49.7% were boys, and 80.0% were of Tibetan. CHD was identified in 293 children, with an overall prevalence of 6.73 ‰. Among them, 239 were unrecognized CHD, yielding a prevalence of 5.49 ‰. Atrial septal defect accounted for 51.9% of the CHD, followed by patent ductus arteriosus (31.1%), ventricular septal defect (9.9%). The CHD prevalence was significantly higher in female (8 ‰), Han race (18 ‰), children lived in Qumalai county (13 ‰), and children lived in a higher altitude (13 ‰). Female had greater prevalence of total CHD, atrial septal defect, and patent ductus arteriosus, but insignificant difference was observed in ventricular septal defect prvalence than male. In multivariable logistic regression analyses, female (OR, 1.48; 95% CI, 1.17–1.87, P = 0.001), Han population (OR, 3.28; 95% CI, 1.67–6.42, P = 0.001), and higher altitudes (OR, 2.28; 95% CI, 1.74–3.00, P Conclusions The prevalence of CHD in Qinghai province was 6.73 ‰. Altitude elevation, female, and Han population were independently association with CHD prevalence.

Objectives: Although the latest international guidelines recommend the use of uninterrupted non-vitamin K antagonist oral anticoagulants (NOAC) during atrial fibrillation (AF) ablation, it does not reflect current clinical practice, as most centers still use a minimally interrupted NOAC strategy. The purpose of this study was to evaluate the safety and effectiveness of minimally interrupted NOAC compared with bridging therapy and uninterrupted vitamin K antagonist (VKA) for nonvalvular AF ablation.Patients and Methods: A total of 4520 patients who underwent AF ablation between January 2010 and December 2018 were included in the analysis. According to their periprocedural anticoagulation strategies, patients were divided into three groups: Bridging heparin group (n = 1848); Uninterrupted VKA group (n = 796) and Minimally interrupted NOAC group (Total n = 1876; dabigatran: n = 865; rivaroxaban, n = 1011). A combined complication endpoint (CCE) as composed of any bleeding complications and thromboembolic events was analyzed.Results: Rates of thromboembolisms were similar among the three groups (0.22% for Bridging heparin group, 0.25% for Uninterrupted VKA group, and 0.11% for Minimally interrupted NOAC group, p = 0.626). There was a significant difference among the three groups for the incidence of overall bleeding events (8.50% for Bridging heparin group, 4.52% for Uninterrupted VKA group, and 2.67% for Minimally interrupted NOAC group, p < 0.001). A significant difference of CCE rates was shown in the Minimally interrupted NOAC group as compared with the Uninterrupted VKA group (2.77 vs. 4.77%, p = 0.008) and the Bridging heparin group (2.77 vs. 8.71%, p < 0.001). There was no significant difference in CCE rates among the different NOACs (dabigatran 2.89% vs. rivaroxaban 2.67%, p = 0.773).Conclusions: In patients undergoing AF ablation, minimally interrupted NOACs during the periprocedural period appears safer and equally effective when compared to the bridging heparin and uninterrupted VKA therapy.

In this study we evaluated the feasibility and efficacy of predicting conduction system abnormalities under 3-dimensional (3D) electroanatomic mapping guidance during transcatheter closure of perimembranous ventricular septal defects (pmVSDs) in adults.Methods and Results:The distribution of the His-Purkinje system (HPS) close to the margins of pmVSDs in the left ventricle was identified using 3D electroanatomic mapping and near-field HPS was further confirmed by different pacing protocols. Of the 20 patients in the study, 17 (85%) were successfully treated by transcatheter intervention. The minimum distance between the margins of the pmVSD and near-field HPS, as measured by 3D electroanatomic mapping, ranged from 1.3 to 3.9 mm (mean [± SD] 2.5±0.7 mm). Five patients with a minimum distance2 mm had a higher risk (3/5; 60%) for adverse arrhythmic events, whereas patients with a distance2 mm were at a much lower risk (1/15; 6.7%) of procedure-related conduction block (P=0.032). No other adverse events were recorded during the follow-up period (median 30 months).A minimum distance between the pmVSD and near-field HPS2 mm was associated with a relatively high risk of closure-related conduction block. 3D electroanatomic mapping may be helpful in guiding decision making for transcatheter closure and reduce the incidence of adverse arrhythmic events.

Objectives This study aimed to evaluate the electrophysiological mechanisms of post-surgical atrial tachycardias (ATs) during mapping with an automated high-resolution mapping system (Rhythmia, Boston Scientific, Marlborough, Massachusetts). Background Mapping and ablation of post-operative ATs following previous open-heart surgery is often challenging because the potential mechanisms remain incompletely understood. Methods Fifty-one consecutive patients underwent mapping and ablation of post-surgical ATs. Results A total of 64 ATs were identified, and the mechanism was macro re-entry in 58 of 63 (92.1%) ATs, focal in 4 ATs, localized micro re-entry in 1 AT, and undetermined in 1 AT. Of 11 patients who underwent surgical repair of congenital heart disease, 6 (54.5%) had peri-tricuspid re-entrant AT, 5 had either right atrial (RA) free-wall incisional ATs or figure-8 re-entrant ATs, with an isthmus between the tricuspid annulus and the RA free-wall incision or between the incisions, and none had left atrial (LA) or focal ATs. In 32 patients with valve replacement and 8 who underwent valvuloplasty, peri-tricuspid ATs were observed in 14 (43.4%) and 6 (75%) patients, RA free wall or septal incisions-related ATs were seen in 7 and 2 patients, and LA macro re-entrant ATs were observed in 12 patients and 1 patient, respectively. A macro pseudo re-entry pattern was identified in 8 of 51 patients (15.7%). All these activations could be easily excluded by manually moving the window of interest, except in 2 cases with a figure-8 re-entrant configuration. Conclusions RA macro re-entrant ATs predominate, irrespective of the types of initial surgical procedures, but LA ATs occur more frequently in patients with valve replacement. Pseudo re-entry atrial activation is common and easily recognized by adjusting the mapping window.

Objectives: The aim of the study was to examine the association of CHADS2/CHA2DS2-VASc scores with left atrial thrombus (LAT) and spontaneous echocardiographic contrast (SEC) in non-anticoagulated nonvalvular atrial fibrillation (NVAF) spontaneous patients, and to develop a new scoring system for LAT/SEC prediction. Methods: Consecutive non-anticoagulated NVAF patients with or without LAT/SEC by transesophageal echocardiography were identified in the Guangdong General Hospital. Results: Among 2,173 patients, the prevalence of LAT/SEC was 4.9%. Both predictive values of CHADS2 and CHA2DS2-VASc scores for the presence of LAT/SEC were low-to-moderate (receiver operating characteristic [ROC] = 0.591 and 0.608, respectively, p = 0.90). By multivariate analysis, non-paroxysmal AF, decreased left ventricular ejection fraction, and left atrial enlargement were positively associated with LAT/SEC, while CHADS2/CHA2DS2VASc scores were not. A new scoring system based on these 3 factors above significantly improved the discrimination for LAT/SEC (ROC = 0.792). Conclusions: CHADS2/CHA2DS2-VASc scores had limited value in predicting LAT/SEC; a new scoring system that combines AF type and echocardiographic parameters may better predict LAT/SEC as a surrogate for cardioembolic risk in NVAF patients.

Background: This study was designed to identify the pathogenic mutation in a Chinese family with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) using whole genome sequencing (WGS). Methods and Results: Probands II:1 and II:2 underwent routine examinations for diagnosis. Genomic DNA was extracted from the peripheral blood of family members and analyzed using WGS. A total of 60,285 single-nucleotide polymorphisms (SNP) and 13,918 insertions/deletions (InDel) occurring in the exonic regions of genes and predisposing to cardiomyopathies and arrhythmias were identified. When filtered using the 1000 Genomes Project (2014 version), NHLBI ESP6500, and ExAC databases, 12 missense SNP and 2 InDel in exonic regions remained, the allele frequencies of which were Conclusions: A homozygous mutation of DSG2 p.F531C was identified as the pathogenic mutation in patients with ARVC/D involving both ventricles, as a result of widened and impaired intercalated discs, interrupted myocardial fibers, and abnormally hyperplastic interstitial fibers, collagen fibers, and adipocytes.

Introduction: Chronic kidney disease (CKD) has been associated with incident atrial fibrillation (AF) and its complications, but data from Asian cohorts are limited. Aim: To explore the relationship of AF recurrence after catheter ablation (CA) with eGFR as a continuous variable, and with different renal function categories (normal: estimated glomerular filtration rate [eGFR] ≥90 mL/min/1.73 m 2; mild CKD: eGFR 60–89 mL/min/1.73 m 2; moderate CKD: eGFR 45–59 mL/min/1.73 m 2; severe CKD: 2), using data from the Guangzhou Atrial Fibrillation Ablation Registry. Methods: We studied consecutive symptomatic adult patients with non-valvular AF, refractory to at least one antiarrhythmic drug and eligible for CA, in Guangdong General Hospital between June 2011 and August 2015. Results: Data were available from 1407 consecutive patients (mean age 57.3 ± 11.5 years; 68% men) with non-valvular AF undergoing radiofrequency or cryoballoon ablation. During a mean follow-up of 20.7 ± 8.8 months, 18.6% of patients with paroxysmal AF and 50.5% with non-paroxysmal AF had AF recurrence. On multivariable analysis, eGFR (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.96–0.97) was an independent risk factor for AF recurrence, with a good predictive value (area under the curve 0.74, 95% CI 0.72–0.77; P < 0.01). In the normal renal function, and mild, moderate and severe CKD categories, AF recurrence rates were 11.5%, 29.3%, 72.0% and 93.3%, respectively. Compared with normal renal function, there were stepwise increased risks of AF recurrence with mild CKD (HR 3.30, 95% CI 2.55–4.26; P < 0.01), moderate CKD (HR 9.43, 95% CI 6.76–13.16; P < 0.01) and severe CKD (HR 12.35, 95% CI 6.93–21.99; P < 0.01). Conclusions: In a large cohort of Asian patients with AF, renal dysfunction increased the risk of AF recurrence after CA. AF recurrence gradually increased with worsening kidney function in this cohort.

ObjectivesThere are country and regional variations in the prevalence of hyperuricaemia (HUA). The prevalence of HUA and non-valvular atrial fibrillation (NVAF) in southern China is unknown.DesignA cross-sectional study.Setting and participantsA total of 11 488 permanent residents aged 35 or older from urban and rural areas of Guangzhou, China were enrolled. A questionnaire was used to compile each participant’s demographic information and relevant epidemiological factors for HUA and NVAF. All participants were assessed using a panel of blood tests and single-lead 24-hour ECG.Main outcome measuresHUA was defined as serum uric acid level >420 μmol/L in men and >360 μmol/L in women. NVAF was diagnosed as per guidelines.ResultsThe prevalence of HUA was 39.6% (44.8% in men and 36.7% in women), and 144 residents (1.25%) had NVAF. Prevalence of HUA increased with age in women but remained stably high in men. After adjusting for potential confounders, age, living in urban areas, alcohol consumption, central obesity, elevated fasting plasma glucose level, elevated blood pressure, lower high-density lipoprotein cholesterol level and elevated triglycerides level were associated with increased risk of HUA. Residents with HUA were at higher risk for NVAF. Serum uric acid level had a modest predictive value for NVAF in women but not men.ConclusionsHUA was highly prevalent among citizens of southern China and was a predictor of NVAF among women.

Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. About half of sudden deaths from AMI are mainly because of malignant ventricular arrhythmias (VA) after AMI. The sodium channel gene SCN5A and potassium channel genes KCNQ1 and KCNH2 have been widely reported to be genetic risk factors for arrhythmia including Brugada syndrome and long QT syndrome (LQTS). A few studies reported the association of SCN5A variant with ventricular tachycardia (VT)/ventricular fibrillation (VF) complicating AMI. However, little is known about the role of KCNQ1 and KCNH2 in AMI with VA (AMI_VA). This study focuses on investigating the potential variants on SCN5A, KCNQ1, and KCNH2 contributing to AMI with VA in a Chinese population.In total, 139 patients with AMI_VA, and 337 patients with AMI only, were included. Thirty exonic sites were selected to be screened. Sanger sequencing was used to detect variants. A subsequent association study was also performed between AMI_VA and AMI.Twelve variants [5 on KCNH2(NM_000238.3), 3 on KCNQ1(NM_000218.2), and 4 on SCN5A(NM_198056.2)] were identified in AMI_VA patients. Only 5 (KCNH2: c.2690AC; KCNQ1: c.1927GA, c.1343delC; SCN5A: c.1673AG, c.3578GA) of them are missense variants. Two (KCNQ1: c.1343delC and SCN5A: c.3578GA) of the missense variants were predicted to be clinically pathogenic. All these variants were further genotyped in an AMI without VA group. The association study identified a statistically significant difference in genotype frequency of KCNH2: c.1539CT and KCNH2: c.1467CT between the AMI and AMI_VA groups. Moreover, 2 rare variants (KCNQ1: c.1944CT and SCN5A: c.3621CT) showed an elevated allelic frequency (more than 1.5-fold) in the AMI_VA group when compared to the AMI group.Twelve variants (predicting from benign/VUS to pathogenic) were identified on KCNH2, KCNQ1, and SCN5A in patients with AMI_VA. Genotype frequency comparison between AMI_VA and AMI identified 2 significant common variants on KCNH2. Meanwhile, the allelic frequency of 2 rare variants on KCNQ1 and SCN5A, respectively, were identified to be enriched in AMI_VA, although there was no statistical significance. The present study suggests that the ion-channel genes KCNH2, KCNQ1, and SCN5A may contribute to the pathogenesis of VA during AMI.

BackgroundBiomarkers have been related to the arrhythmia recurrence following catheter ablation (CA) of atrial fibrillation (AF). We hypothesized that concurrent measurement of several biomarkers would additively improve their predictive value.MethodsOne thousand four hundred and ten consecutive AF patients (68% male; 57.2 ± 11.6 years) undergoing CA were enrolled. Baseline characteristics, serum B type brain natriuretic peptide (BNP) and high sensitivity C reactive protein (hsCRP), estimated glomerular filtration rate (eGFR), ablation parameters, arrhythmia data at discharge, 1, 3, 6, and then every 6 months post CA were collected. Follow-up ended when arrhythmia recurred or until 31st December 2016.ResultsThree hundred and sixty-five (25.9%) patients had arrhythmia recurrence post-CA during a mean follow-up of 20.7 ± 8.8 months. BNP, hsCRP, and eGFR levels and their cut-off values of 237.45 pg/mL, 1.6 mg/dL, and 82.5 mL/min/1.73 m2 were good predictors for AF recurrence (all P < 0.01). On multivariate analysis, increasing BNP and hsCRP, decreasing eGFR, gender, and early recurrence (ER) were independent predictors of AF recurrence (all P < 0.01). Compared to BNP alone, BNP plus eGFR or both eGFR and CRP showed incrementally better predictive values (ROC comparisons, all P < 0.01). Similar findings were evident in the subgroups of patients with paroxysmal or nonparoxysmal AF.ConclusionMeasurement of BNP, CRP, and eGFR were incrementally additive to clinical risk factors in a cumulative manner to improve prediction of arrhythmia recurrence post-CA of AF. The implications of poor arrhythmia outcome in AF patients with multiple abnormal biomarkers pre-CA procedure may help with patient selection and inform the likelihood of success or the need of more complicated CA procedure(s).

Aims Cerebrovascular complications are relatively uncommon, but severe adverse events are associated with catheter ablation of atrial fibrillation (AF). This study aimed to investigate the incidence, risk factors, and hospital outcomes of cerebrovascular events complicating AF ablation. Methods and results Cerebrovascular complications occurring during the procedure or hospitalization after AF ablation were assessed. Cerebrovascular events occurred in 9 of 1946 consecutive procedures (0.46%). Seven patients (0.36% per procedure) were diagnosed with ischaemic stroke and two patients (0.1% per procedure) with intracranial haemorrhage (ICH). Six events (6/9, 66.7%) occurred during the ablation and the remainders within 24 h after the ablation. Multivariable analysis revealed that previous ischaemic stroke [odds ratio (OR) 10.549; 95% confidence interval (CI) 2.551–43.625, P = 0.001] and mechanical valve replacement (OR 3.261; 95% CI 1.337–7.953, P = 0.009) were independent predictors. In a separate model, CHA2DS2-VASc score ≥3 (OR 7.992; 95% CI 2.046–31.215, P = 0.003) and mechanical valve replacement (OR 4.104; 95% CI 1.644–10.245, P = 0.002) were significantly associated with cerebrovascular complications. All patients survived to discharge except the two cases with ICH. Conclusion Cerebrovascular complications related to catheter ablation of AF are relatively infrequent and typically occur early either during the procedure or within the first 24 h after AF ablation. Previous ischaemic stroke, mechanical valve replacement, and CHA2DS2-VASc score ≥3 are independent predictors of such complications. The majority of these events are ischaemic stroke with a benign clinical outcome, while ICH may correlate with poor prognosis.

Background Cardiac involvement in Danon disease typically manifests as left ventricular hypertrophy (LVH) and ventricular preexcitation. This study aimed to identify patients with Danon disease among patients with LVH and concurrent electrocardiographic preexcitation. Methods Electrocardiographic preexcitation was identified in 10 of 197 patients with unexplained LVH in whom genetic testing was performed using next‐generation sequencing. Results Three (3/10, 30%) patients with Danon disease were found in association with different mutations in the gene of lysosome‐associated membrane protein 2 (LAMP2). Compared to seven patients without Danon disease, these three patients presented with distinctive clinical phenotypes, including onset at an earlier age (20 ± 2 years vs. 53 ± 9 years, p

Background The ECG characteristics of the distal coronary venous system ventricular arrhythmias (VAs) share common features with VAs arising from the aortic cusps or the endocardial left ventricular outflow tract (LVOT) beneath the cusps. The purpose of this study was to identify specific electrocardiographic and electrophysiological characteristics of VAs originating from the distal great cardiac vein (GCV). Methods Based on the successful ablation site, patients with idiopathic VAs from the distal GCV, left coronary cusp (LCC) or the subvalvular left ventricular outflow tract (LVOT) area were included in the present study. Results The final population consisted of 39 patients (35 males, mean age 51 ± 23 years). All VAs displayed a right bundle branch block (RBBB) morphology with inferior axis. Among these patients, 15 were successfully ablated at the GCV, 15 at the LCC and 9 at the subvalvular region. A “w” pattern in lead I was present in 12 out of 15 (80%) VAs originating from the distal GCV compared to none of VAs arising from the other two sites (p

BACKGROUND: Obesity or overweight is related to worse outcomes in patients with atrial fibrillation (AF) following catheter ablation (CA). The role of being underweight in relation to recurrent arrhythmias post AF ablation is less certain. We conducted a retrospective study to investigate the association of body mass index (BMI) with arrhythmia outcomes in AF patients undergoing CA.METHODS: In a cohort of 1410 AF patients (mean age 57.2 ± 11.6 years; 68% male) undergoing single CA, the association between BMI and AF ablation outcome was analyzed using BMI as a continuous variable and by four BMI categories (RESULT: We observed a positive association between a cut off value of BMI and risk of AF recurrence post AF ablation. BMI ≥26.36 kg/m2 was related to more AF recurrence (c-statistic 0.55, 95%CI 0.51-0.58; P CONCLUSION: BMI had good predictive value for AF ablation outcomes with a cut off value of ≥26.36 kg/m2. Apart from being obese/overweight, being underweight might also be a risk factor for AF recurrence post ablation.

Background Sudden cardiac death (SCD) induced by malignant ventricular tachycardia (MVT) among young adults with right ventricular cardiomyopathy/dysplasia (ARVC/D) is a devastating event. Parts of ARVC/D patients have a mutation in genes encoding components of cardiac desmosomes, such as desmoglein-2 (DSG2), plakophilin-2 and desmoplakin. Case presentation Here we report a potentially pathogenic mutation in the DSG2 gene, which was identified in a family with ARVC/D using Whole Exome Sequencing (WES) and Sanger Sequencing. In all, Patient III:1 with ARVC/D carried the compound heterozygous mutations of DSG2 p.F531C and KCNE5 p.D92E/E93X, which were both inherited from her mother (II:2), who died of SCD. Carriers of DSG2p.F531C showed various phenotypes, such as ARVC/D, SCD, MVT and dilated cardiomyopathy. For III:1, there were significant low-voltage regions in the inferior-apical, inferior-lateral wall of the right ventricular epicardium and outflow tracts of the right ventricle. Under the guidance of a three-dimensional mapping system, MVT was successfully ablated with an epicardial–endocardial approach targeting for late, double or fragmental potentials after implantable cardioverter-defibrillator (ICD) electrical storms. No VT recurrence was observed during the one year of follow-up. Conclusions When coexisting with heterozygous KCNE5 p.D92E/E93X, heterozygous DSG2 p.F531C as a genetic background was found to predispose to ARVC/D, SCD and MVT, which were successfully ablated using an epicardial–endocardial approach. Electronic supplementary material The online version of this article (10.1186/s12881-018-0580-2) contains supplementary material, which is available to authorized users.

This study sought to determine the long-term outcomes of catheter ablation (CA) of ventricular tachycardia (VT) in a series of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) without background implantable cardioverter-defibrillator (ICD) therapy.Endo-epicardial CA of VT has been demonstrated to be highly effective in reducing recurrent VT in patients with ARVC.Thirty-two patients (age 45 ± 13 years, 72% male) with ARVC and VT underwent CA in the absence of ICD therapy. ICD was recommended in all cases, but implantation was not performed due to patient refusal (63%) or financial hardship (37%). CA was guided by activation/entrainment mapping for mappable VT and pace mapping/targeting of abnormal substrate in cases of unmappable VT.Symptoms associated with clinical VT included palpitations (78%), chest pain and shortness of breath (22%), pre-syncope (16%), and syncope (13%). Prior to ablation, 22 patients (69%) failed a mean of 1.3 ± 0.5 antiarrhythmic drugs. Epicardial mapping and ablation was performed as first-line strategy (20 [63%]) or in case of recurrent VT or persistent inducibility after endocardial-only ablation (3 [9%]-surgical epicardial cryoablation in 1 patient). After a mean of 1.6 (range 1 to 3) procedures, all patients demonstrated noninducibility of sustained VT from at least 2 RV sites; 75% also had stimulation on isoproterenol with no inducible VT. At a median follow-up of 46 months (range 26 to 65 months) following the last ablation, no deaths were observed and freedom from recurrent VT was 81%.In this multicenter international registry of patients with ARVC and VT, CA performed in the absence of background ICD was associated with a low rate of symptomatic VT recurrence (19%) without mortality during 46-month median follow-up. These data suggest that further prospective studies may refine selection of patients with structural heart disease at low risk for SCD, possibly obviating the benefit of ICD therapy.

Background: Female sex has been linked with worse prognosis in patients with atrial fibrillation (AF). Clinical risk stratification of women with AF may help decision-making before catheter ablation (CA). Aim: To evaluate arrhythmia outcomes and the predictive value of clinical scores for arrhythmia recurrence in a large cohort of Chinese patients with AF undergoing CA. Methods: A total 1410 of patients (68.1% men) who underwent AF ablation with scheduled follow-up were analysed retrospectively. Baseline characteristics and ablation outcome were compared between men and women. The predictive values of risk scoring systems for AF recurrence were assessed in women. Results: Recurrence, early recurrence and complications after CA were similar in women and men over similar follow-up periods (20.7 ± 8.0 vs 20.7 ± 9.1 months; P > 0.05). Compared with men, women with AF recurrence were older and had a larger left atrial diameter (LAD), less paroxysmal AF, lower left ventricular ejection fraction, lower estimated glomerular filtration rate (eGFR) and higher serum concentrations of B-type natriuretic peptide (BNP) and C-reactive protein (CRP) (all P < 0.01). Multivariable analysis showed that age, non-paroxysmal AF, body mass index, coronary artery disease, LAD, early recurrence, eGFR, BNP and CRP were independent risk factors with sex differences (all P < 0.05) in the whole cohort. In women, only non-paroxysmal AF, early recurrence, BNP, CRP (all P < 0.01) and history of stroke/transient ischaemic attack (P = 0.016) were independent risk factors. Of the clinical scoring systems tested, MB-LATER, APPLE, CAAP-AF and BASE-AF2 scores (C-indexes 0.73, 0.72, 0.68 and 0.72, respectively; all P < 0.01) had a modest predictive value for AF recurrence after CA in women. Conclusions: CA for AF has similar recurrence risks in women and men, but there are sex differences in the clinical characteristics and risk factors associated with AF recurrence.

INTRODUCTION: Several clinical scoring systems have been derived to predict the arrhythmia outcome of catheter ablation (CA) for atrial fibrillation (AF) but which is better is not clear. Simple clinical risk scores (that any clinician can use in the everyday clinic) can help assess the likelihood of recurrence of AF following CA and the simple MB-LATER score has recently been described. We compare the predictive ability of seven existing clinical scoring systems (HATCH, CHADS2 , CHA2 DS2 -VASc, BASE-AF2 , APPLE, CAAP-AF, and MB-LATER) in a Chinese cohort of AF patients undergoing CA.METHODS AND RESULTS: 1410 patients (mean age 57.2 ± 11.6 years; 68% male) with AF undergoing CA during 2011-2015 were enrolled in final analysis. Symptoms, 12 lead ECG and Holter ECGs were recorded before discharge, and at 1, 3, 6 months, and every 6 months thereafter to detect the arrhythmia relapse. During a mean 20.7 ± 8.8-month follow-up, recurrence occurred in 365 patients(25.9%). All tested scores were predictors of AF recurrence with areas under the curve (AUCs) of 0.58, 0.57, 0.57, 0.75, 0.74, 0.71, and 0.73 respectively (all P < 0.01). Compared to all other scores, the MB-LATER score showed improved reclassification (NRI range 30%-82.6%, P < 0.01) and discrimination indexes (IDI range 2.6%-18.6%, all P < 0.01) in predicting AF recurrence.CONCLUSION: Based on net reclassification and discrimination analysis, the MB-LATER score performed best for predicting AF recurrent postablation, in a large "all comers" Chinese cohort. This simple clinical risk score (that any clinician can use in the everyday clinic) can help assess the likelihood of recurrence of AF following catheter ablation.

To investigate the safety and midterm outcome of concomitant left atrial appendage (LAA) closure and catheter ablation (CA) as a one-stage hybrid procedure for non-valvular atrial fibrillation (AF) in a multicenter registry. A total of 50 consecutive patients with symptomatic drug-resistant non-valvular AF with CHA2DS2-VASc score ≥ 2 and contraindications for antithrombotic therapy were included in the prospectively established LAA closure registry, and underwent concomitant LAA closure (48 for WATCHMAN and 2 for ACP) and CA procedure (40 for radiofrequency and 10 for cryoballoon CA). Two cardiac tamponades, one peripheral vascular complications and one mild air embolism were observed during perioperative period. After mean follow-up of 20.2 ± 11.5 months, 18 (36%) patients presented with atrial arrhythmia relapse and 45 (91.8%) patients presented with complete sealing; furthermore, there were two transient ischemic attacks and one ischemic stroke under an off-oral anticoagulant situation, respectively. Concomitant CA and LAA closure as a one-stage hybrid procedure might be feasible and potentially decrease costs in patients with symptomatic non-valvular AF with high stroke risk and contraindication to antithrombotic treatment, and as safe as LAA closure procedure only during the perioperative period. However, it was necessary to further validate the mid-term safety.