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Background: Managing patients with atrial fibrillation (AF) and comorbid heart failure (HF) with reduced (HFrEF) or mildly reduced ejection fraction (HFmrEF) is of clinical importance but a great challenge. This study aimed to evaluate the clinical benefit of the combined radiofrequency catheter ablation (RFCA) and left atrial appendage closure (LAAC) procedure in AF patients complicated with systolic HF. Methods: AF patients with HFrEF or HFmrEF who underwent the combined RFCA and LAAC procedure were prospectively enrolled in the LAACablation registry. The procedural complications and long-term outcomes were evaluated. Another cohort of AF patients with systolic HF who did not undergo either RFCA or LAAC were used for prognosis comparison. Results: Among 802 AF patients who underwent the combined procedure, 65 patients were comorbid with systolic HF (25 with HFrEF and 40 with HFmrEF). The overall procedural complication rate was 9.2%, which was mainly attributed to acute decompensated HF (6.2%). Accompanied with markedly reduced AF burden (from median [25th, 75th percentile]: 100 [100, 100] to 0 [0, 1.2]%, p < 0.001), upward trajectories of cardiac function were observed in 51 (78.4%) patients, showing improvement in New York Heart Classification (p < 0.01), natriuretic peptide levels (from 1492 [809, 3259] to 413 [163, 880] pg/mL, p < 0.001) and left ventricular EF (from 42.6 ± 5.3 to 53.8 ± 8.2%, p < 0.001). During the 27-month follow-up period, death, thromboembolism, major bleeding, and HF rehospitalization were observed in three, one, one, and four patients, respectively. The observed event rates showed a significant reduction compared with the non-procedure AF-HF cohort (n = 138; for composite endpoint: hazard ratio: 2.509, 95% confidence interval: 1.415–4.449, p = 0.002) and with the respective rates predicted by risk scores. Conclusions: Combining RFCA and LAAC achieves acceptable safety and credible long-term efficacy in AF patients with systolic HF. Further randomized studies are warranted in a larger patient cohort. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation (CA) combined with left atrial appendage occlusion (LAAO) is a feasible approach for atrial fibrillation (AF) patients. Its role in octogenarians with AF is unclear. Hypothesis: In AF patients over 80 years, CA combined with LAAO is a feasible way in restoring sinus rhythm and preventing stroke. Methods: This is a single‐center retrospective study. Patients who underwent CA and LAAO in a single procedure between March 2018 and December 2020 were included. Efficacy endpoints included procedural success rate, AF recurrence rate, and thromboembolic events. Safety endpoints included pericardial effusion/cardiac tamponade, device‐related thrombus (DRT), all‐cause death, and major bleeding. Results: Five hundred and five patients (mean age 69.5 ± 7.7 years; 230 [45.5%] female) were included, with 46 (9.1%) patients aged ≥80 years old (octogenarian group). Prevalence of paroxysmal AF (25 [54.3%] vs. 207 [45.1%], p < 0.001) and CHA2DS2VASc score (4.1 ± 1.3 vs. 3.1 ± 1.4, p < 0.0001) were higher in octogenarian patients. There were six cases (1.2%) of pericardial effusion (all in nonoctogenarian patients). At 3 months postprocedure, 437 patients underwent TEE/CT. Thirty‐two (80%) octogenarian patients and 308 (77.6%) nonoctogenarian patients had no peri‐device leak. After a mean follow‐up of 26.9 ± 9.1 months, AF was documented in 10 (21.7%) patients in octogenarian group and in 103 (22.4%) patients in nonoctogenarian group (p = 0.99). The annual thromboembolic risk was 2.1% and 0.8% in the octogenarian group and nonoctogenarian group, respectively. Death occurred in 16 nonoctogenarian patients. One major bleeding was recorded in the octogenarian group. Conclusions: The combination of CA and LAAO in a single procedure is a feasible treatment option in octogenarians with comparable efficacy and safety profile. [ABSTRACT FROM AUTHOR]

Aims Activation mapping of premature atrial complexes (PACs) proves challenging due to interference by mechanical bumping and non-targeted ectopies. This study aims to compare the mapping efficacy, instant success, and long-term recurrence of catheter ablation for PACs with non-pulmonary vein (PV) and non-superior vena cava (SVC) origins between the novel dual-reference approach (DRA) and the routine single-reference approach (SRA) of mapping. Methods and results Patients with symptomatic, drug-refractory PACs, or frequent residual PACs after atrial tachyarrhythmia ablation were enrolled. During activation mapping, the coronary sinus (CS) catheter was used as the only timing reference in the SRA group. In the DRA group, another catheter, which was spatially separated from the CS catheter, was used as the second reference. The timing difference between the two references was used to discriminate the targeted PACs from the uninterested rhythms. Procedural parameters and long-term recurrence were compared. A total of 188 patients (109 in SRA and 79 in DRA) were enrolled. The baseline characteristics were similar. Compared with the SRA group, the DRA group had less repeated mapping (1.2 ± 0.4 vs. 1.4 ± 0.5, P = 0.004), shorter mapping (15 ± 6 vs. 23 ± 7 min, P < 0.001) and procedural time (119 ± 28 vs. 132 ± 22 min, P = 0.001), similar procedural complication rates (3.6 vs. 3.8%, P > 0.999), higher instant success (96.2 vs. 87.2%, P = 0.039), and lower recurrence rate (15.2 vs. 29.3%, hazard ratio 1.943, P = 0.033) during a 24-month follow-up. Conclusion As a novel strategy, the DRA shortens the procedural time and improves both instant and long-term success of PAC ablation, serving as a promising approach in mapping PACs with non-PV and non-SVC origins. [ABSTRACT FROM AUTHOR]

Background. Combined atrial fibrillation (AF) ablation and left atrial appendage closure (LAAC) has been practiced for management of both the symptoms and the high stroke risk of AF. Data of the combined procedure in selected patients with prior stroke are limited. The aim of this study is to compare the safety and efficacy of combined catheter ablation and LAAC between AF patients with and without prior stroke. Methods and Results. This retrospective study enrolled 296 patients who underwent combined procedures of AF ablation and LAAC. Patients were divided into two groups: 81 patients with prior stroke (Stroke group) and 215 patients without prior stroke (Control group). Combined procedures were successfully performed in all the patients. Patients in the Stroke group had higher CHA2DS2-VASc scores (4.9 ± 1.2 vs. 3.2 ± 1.0, P < 0.001) and higher HAS-BLED scores (3.5 ± 1.1 vs. 3.0 ± 1.0, P < 0.001) compared with those in the Control group. Procedure-related complications in the Stroke group included two pericardial effusions and two groin hematomas, which did not differ significantly fromthe Control group (4.9% vs. 4.2%, P = 0.778). After a mean follow-up of 20 months, the AF-free rate of the Stroke group was comparable with that of the Control group (64.2% vs. 68.4%, P = 0.495). The relative risk reductions in stroke and bleeding (observed rate compared to that predicted from the CHA2DS2-VASc and HAS-BLED scores) were 80% and 79%, respectively, in the Stroke group, and 62% and 62%, respectively, in the Control group. Conclusions. The combination of catheter ablation and LAAC is safe and efficient in selected AF patients with prior stroke. It was observed that patients with prior stroke may benefit more from risk reductions of stroke and bleeding following the combined procedure. [ABSTRACT FROM AUTHOR]

Objectives: To explore the value of detecting the peri‐device leak (PDL) and device endothelialization after left atrial appendage closure (LAAC) by cardiac computed tomography (CT) in patients with atrial fibrillation (AF), who underwent Watchman LAAC combined with radiofrequency ablation of atrial fibrillation (AFCA). Methods: Patients with symptomatic drug‐refractory atrial fibrillation at high risk of stroke (CHA2DS2‐VASc Score ≥ 2), who underwent Watchman LAAC combined with AFCA in our center from March 2017 to December 2018 were enrolled. Maximum diameter of LAA orifice was determined by preoperative CCTA. A standardized view of Watchman device was obtained by postoperative CCTA multiplannar reconstruction to evaluate the PDL and device endothelialization. Results: Approximately 84 patients post successful LAAC and AFCA were enrolled in this study. The satisfactory LAA occlusion rate was 100%. There was no death, bleeding, stroke, and device‐related thrombus (DRT) events. At 6‐month postprocedure, CCTA images evidenced complete endothelialization in 44 patients (no contrast enhancement in LAA); contrast enhancement in LAA and visible PDL in 33 patients; contrast enhancement in LAA but without PDL in seven patients (incomplete device endothelialization). Maximum diameter of LAA orifice could independently predict the occurrence of PDL (odds ratio, 1.31; 95% confidence interval, 1.11–1.55; p =.002), sensitivity was 69.7% and specificity was 80.4% with the cutoff value of maximum diameter of LAA orifice more than 28.2 mm on predicting PDL. Conclusions: CCTA is feasible to evaluate PDL and device endothelialization after LAAC. The maximum diameter of LAA orifice derived from CT can independently predict the occurrence of post‐LAAC PDL. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to describe the feasibility of a surgical left thoracotomy for catheter ablation of scar-related ventricular tachycardia (VT) in patients with inaccessible pericardial access. Background: Pericardial adhesion due to prior cardiac surgery or previous epicardial ablation procedures limits epicardial access in patients with drug-refractory VT originated from the epicardium. Methods: Six patients who underwent a surgical left lateral thoracotomy epicardial access for catheter ablation of VT after failed subxiphoid percutaneous epicardial access were reviewed. Patients' baseline characteristics and procedural characteristics including epicardial access, mapping, and ablation were described. Epicardial access was successfully obtained in all patients by a surgical left lateral thoracotomy. Results: The reasons of pericardial adhesion were prior cardiac surgery (n = 3, 50%) and previous epicardial ablation procedures (n = 3, 50%). Epicardial mapping of the lateral and inferior left ventricle was acquired, and a total of 15 different VTs originated from those regions were abolished. Unless one patient with ST elevation myocardial infarction due to periprocedural occlusion of the posterior descending artery no further complications occurred. All patients were discharged 10.2 ± 4 days after the procedure. VT recurred in 1 patient (17%) and was controlled with oral amiodarone therapy during follow-up (median follow-up: 479 days). Conclusions: A surgical left lateral thoracotomy is feasible and safe for selected patients. This approach provides epicardial ablation in patients with VT located at the infero-lateral left ventricle and pericardial adhesions due to previous cardiac surgery or previous ablation procedures. [ABSTRACT FROM AUTHOR]

Aims  We evaluated the feasibility of left atrial appendage (LAA) closure guided by the image fusion of integrating fluoroscopy into 3D computed tomography (CT). Methods and results  A total of 117 consecutive patients who underwent LAA closure with or without the image fusion were matched (1:2). Each LAA closure step of the Image fusion group was guided by the preprocedure CT and image fusion, especially in the plan of LAA measurement and transseptal puncture. All patients were successfully implanted with a WATCHMAN closure device. Comparing the two groups, the mean number of recapture times and the number of devices per patient of the Image fusion group were significantly lower (0.4 ± 0.5 vs. 0.7 ± 0.8, P  = 0.031 and 1.0 ± 0.2 vs. 1.1 ± 0.3, P  = 0.027, respectively). The one-time successful deployment rate by the support of the image fusion was higher than in the control group (66.7% vs. 44.9%, P  = 0.026). Each case of the Image fusion group was completely occluded with one transseptal puncture, while five of the Non-image fusion group required redo transseptal punctures. During the 45-day follow-up, both group cases presented occlusion efficiency and no major adverse cardiac events were observed. Conclusion  Image fusion technique integrating fluoroscopy into the 3D CT is safe and feasible which can be easily incorporated into the procedural work-flow of percutaneous LAA closure. The fusion image can play an important alternative role in the plan of LAA measurement and transseptal puncture site for improving the LAA closure procedure. [ABSTRACT FROM AUTHOR]

Background: Premature ventricular complexes (PVCs) exhibit circadian fluctuation. We determine if PVCs of different origin exhibit specific circadian patterns.Methods: We analyzed Holter recordings from patients with monomorphic PVCs who underwent catheter ablation. PVC circadian patterns were classified as fast-heart rate- (HR-) dependent (F-PVC), slow-HR-dependent (S-PVC), or HR-independent (I-PVC). PVC origins were determined intraprocedurally.Results: In a retrospective cohort of 407 patients, F-PVC and S-PVC typically exhibited diurnal and nocturnal predominance, respectively. Despite decreased circadian fluctuation, I-PVC generally had heavier nocturnal than diurnal burden. PVCs of left anterior fascicle origin were predominantly S-PVC, while those of posterior hemibranch origin were mostly F-PVC. PVCs originating from the aortic sinus of Valsalva (ASV) were predominantly I-PVC, while most PVCs arising from the left ventricular outflow tract (LVOT) were F-PVC. Using a diurnal/nocturnal PVC burden ratio of 0.92 as the cutoff value to distinguish LVOT from ASV origin achieved 97% sensitivity and, as further verification, an accuracy of 89% (16/18) in a prospective cohort of patients with PVCs originating from either ASV or LVOT. In contrast, PVCs originating from right ventricles, such as right ventricular outflow tract, did not show distinct circadian patterns.Conclusions: The circadian patterns exhibit origin specificity for PVCs arising from left ventricles. An analysis of Holter monitoring provides useful information on PVC localization in ablation procedure planning. [ABSTRACT FROM AUTHOR]

Aim: The feasibility and safety of performing the combined procedure of catheter ablation (CA) and left atrial appendage closure (LAAC) for atrial fibrillation (AF) have been reported by observational studies without controls. The aim of this study was to compare the procedural and long-term outcomes of combined procedures with isolated CA or LAAC.Methods and Results: This study included patients who underwent combined CA and LAAC (combined group), CA alone (CA-only group), or LAAC alone (LAAC-only group). Propensity score matching was used to select controls from the CA-only and LAAC-only groups. Each group contained 76 subjects. The procedures were successfully performed in all the patients. Procedure-related complications of the combined group included one pericardial effusion and two groin haematomas, which did not differ significantly with those of the CA-only group (3.9% vs. 2.6%, P=0.650) or the LAAC-only group (3.9% vs. 2.6%, P=0.650), respectively. The AF-free rate of the combined group was comparable with that of the CA-only group after a mean of 2 years follow-up (67.1% vs. 69.7%, P=0.727). Compared with the LAAC-only group, the combined group achieved similar complete occlusion rate at implant (94.7% vs. 93.4%) and at 45 days (82.9% vs. 85.5%). At the end of follow-up, ischemic stroke and bleeding events of the combined group were low (3.9%) and were comparable with those of the CA-only group (5.3%) and the LAAC-only group (2.6%).Conclusions: The combination of AF-CA and LAAC is safe and efficacious compared with single procedures alone. [ABSTRACT FROM AUTHOR]

Aims: Ventricular arrhythmias (VAs) originating from the para‐Hisian region represent a challenging location. The long‐term success rate of catheter ablation above the septal leaflet of the tricuspid valve is not ideal. This study aimed to investigate the safety and efficacy of catheter ablation for para‐Hisian VAs via a direct approach under the septal valve with reversed C‐curve technique. Methods and Results: Twenty‐five consecutive patients with para‐Hisian VAs were included. Systematic mapping was performed in the right ventricle septum, including both the regions above and under the septal valve. Radiofrequency (RF) ablation was preferentially performed under the valve with reversed C‐curve technique in all patients. If the ablation failed under the valve, it was then performed above the valve and even in aortic sinus cusps. The earliest ventricular activation preceding surface QRS (V‐QRS) under the valve was significantly larger than that above the valve (34.8 ± 5.3 vs 27.8 ± 5.7 ms, P < .01). RF ablation under the valve with reversed C‐curve technique achieved acute success in 22 of 25 (88%) patients. Junctional rhythm developed during ablation in 3 of 25 (12%) patients and no atrioventricular block occurred. In the remaining three patients, RF application above the valve failed to eliminate the VAs and one of them achieved successful ablation in the right coronary cusp. During a mean follow‐up of 17.8 ± 9.4 months, no patients presented with VAs recurrence and no postprocedure complications occurred. Conclusions: Catheter ablation under the valve with reversed C‐curve technique shows to be effective and safe for para‐Hisian VAs. [ABSTRACT FROM AUTHOR]

Introduction: Catheter ablation of atrial fibrillation (AFCA) and left atrial appendage closure (LAAC) exert opposite effects on left atrial (LA) size. We aim to observe the net impact of combined AFCA and LAAC strategy on LA size and explore those factors which might affect the postprocedure LA structural remodeling. Methods: A total of 53 patients, who underwent combined AFCA and Watchman LAAC in our center from March to December 2017, were enrolled. Atrial fibrillation (AF) recurrence was monitored after the procedure. Left atrial volume (LAV) and left atrial appendage volume (LAAV) were measured by Mimics based on dual‐source computed tomography images. Results: At 6 months, sinus rhythm (SR) was maintained in 79.2% patients. LAV was significantly reduced (130.2 ± 36.3 mL to 107.1 ± 30.0 ml; P < .001) in SR maintenance group, but not in AF recurrence group (138.8 ± 39.3 mL to 137.9 ± 36.9 mL; P = .671). In SR group, preoperative LAAV/LAV ratio (B = −0.894; P = .015), NT‐proBNP (B = 0.005; P = .019) and left ventricular ejection fraction (LVEF) (B = −0.778; P < .001) could interactively affect the extent of postoperative LA structural reverse remodeling, among which LAAV/LAV ratio could independently predict the significance of reverse remodeling (≥15% reduction in LAV) (OR, 0.56; 95% CI, 0.34‐0.90; P = .018). A preoperative LAAV/LAV ratio less than 7.1% is indicative of significant LA structural reverse remodeling in this patient cohort. Conclusions: LA structural reverse remodeling could be evidenced in patients with maintained SR following combined AFCA and LAAC. Smaller LAAV/LAV ratio, higher NT‐proBNP or lower LVEF at baseline are associated with more significant LA structural reverse remodeling, while LAAV/LAV ratio can predict the significance of the process after one‐stop treatment. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 44-year-old male patient with repeated syncope for 5 years referred to our hospital. An electrophysiological study was performed. In addition, increasing the output from the proximal CS region may alter the atrial inputs by penetrating the AV node at more than one input. This phenomenon of treatment can be explained as vagal response caused by adjacent vagus ganglion capture.

Aims: Myocardial infarction (MI) induces neural remodelling of the left stellate ganglion (LSG), which may contribute to ischaemia-induced arrhythmias. The neural chemorepellent Semaphorin 3a (Sema3a) has been identified as a negative regulator of sympathetic innervation in the LSG and heart. We previously reported that overexpression of Sema3a in the border zone could reduce the arrhythmogenic effects of cardiac sympathetic hyperinnervation post-MI. This study investigated whether Sema3a overexpression within the LSG confers an antiarrhythmic effect after MI through decreasing extra- and intra-cardiac neural remodelling.Methods and Results: Sprague-Dawley rats were subjected to MI, and randomly allocated to intra-LSG microinjection of either phosphate-buffered saline (PBS), adenovirus encoding green fluorescent protein (AdGFP), or adenovirus encoding Sema3a (AdSema3a). Sham-operated rats served as controls. Two weeks after infarction, MI-induced nerve sprouting and sympathetic hyperinnervation in the LSG and myocardium were significantly attenuated by intra-LSG injection with AdSema3a, as assessed by immunohistochemistry and western blot analysis of growth-associated protein 43 and tyrosine hydroxylase. This was also confirmed by sympathetic nerve function changes assessed by cardiac norepinephrine content. Additionally, intra-LSG injection with AdSema3a alleviated MI-induced accumulation of dephosphorylated connexin 43 in the infarct border zone. Furthermore, Sema3a overexpression in the LSG reduced the incidence of inducible ventricular tachyarrhythmia by programmed electrical stimulation post-MI, and arrhythmia scores were significantly lower in the AdSema3a group than in the PBS and AdGFP groups.Conclusion: Semaphorin 3a overexpression in the LSG ameliorates the inducibility of ventricular arrhythmias after MI, mainly through attenuation of neural remodelling within the cardiac-neuraxis. [ABSTRACT FROM AUTHOR]

Objectives: We evaluated the acute impact of different cardiac pacing sites on two-dimensional speckle-tracking echocardiography (STE) derived left ventricular (LV) rotation and twist in healthy dogs. Methods: Twelve dogs were used in this study. The steerable pacing electrodes were positioned into right heart through the superior or inferior vena cava, into LV through aorta across the aortic valve. The steerable pacing electrodes were positioned individually in the right atrium (RA), right ventricular apex (RVA), RV outflow tract (RVOT), His bundle (HB), LV apex (LVA) and LV high septum (LVS), individual pacing mode was applied at 10 minutes interval for at least 5 minutes from each position under fluoroscopy and ultrasound guidance and at stabilized hemodynamic conditions. LV short-axis images at the apical and basal levels were obtained during sinus rhythm and pacing. Offline STE analysis was performed. Rotation, twist, time to peak rotation (TPR), time to peak twist (TPT), and apical-basal rotation delay (rotational synchronization index, RSI) values were compared at various conditions. LV pressure was monitored simultaneously. Results: Anesthetic death occurred in 1 dog, and another dog was excluded because of bad imaging quality. Data from 10 dogs were analyzed. RVA, RVOT, HB, LVA, LVS, RARV (RA+RVA) pacing resulted in significantly reduced apical and basal rotation and twist, significantly prolonged apical TPR, TPT and RSI compared to pre-pacing and RA pacing (all P<0.05). The apical and basal rotation and twist values were significantly higher during HB pacing than during pacing at ventricular sites (all P<0.05, except basal rotation at RVA pacing). The apical TPR during HB pacing was significantly shorter than during RVOT and RVA pacing (both P<0.05). The LV end systolic pressure (LVESP) was significantly lower during ventricular pacing than during pre-pacing and RA pacing. Conclusions: Our results show that RA and HB pacing results in less acute reduction on LV twist, rotation and LVESP compared to ventricular pacing. [ABSTRACT FROM AUTHOR]

Aim:To investigate whether resveratrol suppressed oxidative stress-induced arrhythmogenic activity and Ca2+ overload in ventricular myocytes and to explore the underlying mechanisms.Methods:Hydrogen peroxide (H2O2, 200 μmol/L)) was used to induce oxidative stress in rabbit ventricular myocytes. Cell shortening and calcium transients were simultaneously recorded to detect arrhythmogenic activity and to measure intracellular Ca2+ ([Ca2+]i). Ca2+/calmodulin-dependent protein kinases II (CaMKII) activity was measured using a CaMKII kit or Western blotting analysis. Voltage-activated Na+ and Ca2+ currents were examined using whole-cell recording in myocytes.Results:H2O2 markedly prolonged Ca2+ transient duration (CaTD), and induced early afterdepolarization (EAD)-like and delayed afterdepolarization (DAD)-like arrhythmogenic activity in myocytes paced at 0.16 Hz or 0.5 Hz. Application of resveratrol (30 or 50 μmol/L) dose-dependently suppressed H2O2-induced EAD-like arrhythmogenic activity and attenuated CaTD prolongation. Co-treatment with resveratrol (50 μmol/L) effectively prevented both EAD-like and DAD-like arrhythmogenic activity induced by H2O2. In addition, resveratrol markedly blunted H2O2-induced diastolic [Ca2+]i accumulation and prevented the myocytes from developing hypercontracture. In whole-cell recording studies, H2O2 significantly enhanced the late Na+ current (INa,L) and L-type Ca2+ current (ICa,L) in myocytes, which were dramatically suppressed or prevented by resveratrol. Furthermore, H2O2-induced ROS production and CaMKII activation were significantly prevented by resveratrol.Conclusion:Resveratrol protects ventricular myocytes against oxidative stress-induced arrhythmogenic activity and Ca2+ overload through inhibition of INa,L/ICa,L, reduction of ROS generation, and prevention of CaMKII activation. [ABSTRACT FROM AUTHOR]

The expression of the chemorepellent Sema3a is inversely related to sympathetic innervation. We investigated whether overexpression of Sema3a in the myocardial infarction ( MI) border zone could attenuate sympathetic hyper-innervation and decrease the vulnerability to malignant ventricular tachyarrhythmia ( VT) in rats. Survived MI rats were randomized to phosphate buffered saline ( PBS, n = 12); mock lentivirus ( MLV, n = 13) and lentivirus-mediated overexpression of Sema3a ( SLV, n = 13) groups. Sham-operated rats served as control group ( CON, n = 20). Cardiac function and electrophysiological study ( PES) were performed at 1 week later. Blood and tissue samples were collected for histological analysis, epinephrine ( EPI), growth-associated factor 43 ( GAP43) and tyrosine hydroxylase ( TH) measurements. QTc intervals were significantly shorter in SLV group than in PBS and MLV groups (168.6 ± 7.8 vs. 178.1 ± 9.5 and 180.9 ± 8.2 ms, all P < 0.01). Inducibility of VT by PES was significantly lower in the SLV group [30.8% (4/13)] than in PBS [66.7% (8/12)] and MLV [61.5% (8/13)] groups ( P < 0.05). mRNA and protein expressions of Sema3a were significantly higher and the protein expression of GAP43 and TH was significantly lower at 7 days after transduction in SLV group compared with PBS, MLV and CON groups. Myocardial EPI in the border zone was also significantly lower in SLV group than in PBS and MLV group (8.73 ± 1.30 vs. 11.94 ± 1.71 and 12.24 ± 1.54 μg/g protein, P < 0.001). Overexpression of Sema3a in MI border zone could reduce the inducibility of ventricular arrhythmias by reducing sympathetic hyper-reinnervation after infarction. [ABSTRACT FROM AUTHOR]

The impact of angiotensin II receptor blockers (ARBs) on electrical remodelling after myocardial infarction (MI) remains unclear. The purpose of the present study was to evaluate the effect of valsartan on incidence of ventricular arrhythmia induced by programmed electrical stimulation (PES) and potential link to changes of myocardial connexins (Cx) 43 expression and distribution in MI rats. Fifty-nine rats were randomly divided into three groups: Sham ( n = 20), MI ( n = 20) and MI + Val (20 mg/kg/day per gavage, n = 19). After eight weeks, the incidence of PES-induced ventricular tachycardia (VT) and fibrillation (VF) was compared among groups. mRNA and protein expressions of Cx43, angiotensin II type 1 receptor (AT1R) in the LV border zone (BZ) and non-infarct zone (NIZ) were determined by real-time PCR and Western blot, respectively. Connexins 43 protein and collagen distribution were examined by immunohistochemistry in BZ and NIZ sections from MI hearts. Valsartan effectively improved the cardiac function, reduced the prolonged QTc (163.7 ± 3.7 msec. versus 177.8 ± 4.5 msec., P < 0.05) after MI and the incidence of VT or VF evoked by PES (21.1% versus 55%, P < 0.05). Angiotensin II type 1 receptor expression was significantly increased in BZ and NIZ sections after MI, which was down-regulated by valsartan. The mRNA and protein expressions of Cx43 in BZ were significantly reduced after MI and up-regulated by valsartan. Increased collagen deposition and reduced Cx43 expression in BZ after MI could be partly attenuated by Valsartan. Valsartan reduced the incidence of PES-induced ventricular arrhythmia, this effect was possibly through modulating the myocardial AT1R and Cx43 expression. [ABSTRACT FROM AUTHOR]

Background: Recently, left bundle branch area pacing (LBBAP) has been shown to be feasible. However, the right ventricular (RV) implantation site for LBBAP remains elusive. We believe that the RV implantation site should be located at the posteromedial basal septum, and in this paper, we propose a new method to help guide lead implantation. The aim of this study is to demonstrate the feasibility of the proposed method.Methods: The RV implantation site was positioned by a combination of a nine-grid system on fluoroscopy and the use of intracardiac echocardiogram (ICE) and then verified by ICE.Results: Fifteen patients were enrolled for LBBAP using our method. The acute success rate was 86.7% (13/15), which demonstrated that our method is useful for assisting with lead implantation. According to ICE, the distance between the implantation site and apex (the front) and the distance between the implantation site and tricuspid annulus (the back) were 44.9 ± 10.7 and 33.2 ± 10.4 mm, respectively, and the ratio of the front and the back was 1.57 ± 0.80. The distance between the implantation site and the front junction point of the left-right ventricle (the upper) and the distance between the implantation site and the back junction point (the lower) were 33.4 ± 10.6 and 24.5 ± 10.2 mm, respectively. The ratio of the upper to the lower was 1.76 ± 1.36. These results suggest that the implantation site was at the posteromedial basal septum. The width of the QRS duration increased from 110.4 ± 33.1 ms at baseline to 114.1 ± 16.1 ms post LBBAP (P > 0.05). The operation time was 133 ± 32.9 min. The time of X-ray fluoroscopy was 21.2 ± 5.9 min. The mean time for lead positioning during LBBAP was 33.8 ± 16.6 min. During a follow-up of 3 months, the LBB capture threshold remained stable in 12 patients, except for one patient who had an increase in the LBB capture threshold to 3.0 v/0.4 ms.Conclusions: Our preliminary results indicate that the posteromedial basal septum could be seen as the implantation site for LBBAP. As a technique for LBBAP, ICE is a useful method for assisting with lead implantation. It is feasible and safe to use a nine-grid system combined with ICE for LBBAP. [ABSTRACT FROM AUTHOR]