Jianghua Zhang

Renal sympathetic denervation suppresses atrial fibrillation induced by acute atrial ischemia/infarction through inhibition of cardiac sympathetic activity

OBJECTIVE This study aims to explore the effects of renal sympathetic denervation (RSD) on atrial fibrillation (AF) inducibility and sympathetic activity induced by acute atrial ischemia/infarction. METHODS Acute ischemia/infarction was induced in 12 beagle dogs by ligating coronary arteries that supply the atria. Six dogs in the sham-RSD group did not undergo RSD, and six dogs without coronary artery ligation served as controls. AF induction rate, sympathetic discharge, catecholamine concentration and densities of tyrosine hydroxylase-positive nerves were measured. RESULTS Acute atrial ischemia/infarction resulted in a significant increase of AF induction rate, which was decreased by RSD compared to controls (P<0.05). The root-mean-square peak value, peak area and number of sympathetic discharges were significantly augmented by atrial ischemia relative to the baseline and control (P<0.05). The number of sympathetic discharges was significantly reduced in the RSD group, compared to the control and sham-RSD groups (P<0.05). Norepinephrine and epinephrine concentrations in the atria, ventricle and kidney were elevated by atrial ischemia/infarction, but were reduced by RSD (P<0.05). CONCLUSIONS Sympathetic hyperactivity was associated with pacing-induced AF after acute atrial ischemia/infarction. RSD has the potential to reduce the incidence of new-onset AF after acute atrial ischemia/infarction. The inhibition of cardiac sympathetic activity by RSD may be one of the major underlying mechanisms for the marked reduction of AF inducibility.

Impact of contact force technology on reducing the recurrence and major complications of atrial fibrillation ablation: A systematic review and meta-analysis

Contact force (CF) monitoring can be useful in accomplishing circumferential pulmonary vein (PV) isolation for atrial fibrillation (AF). This meta-analysis aimed to assess the efficacy and safety of a CF-sensing catheter in treating AF. Randomized controlled trials or non-randomized observational studies comparing AF ablation using CF-sensing or standard non-CF (NCF)-sensing catheters were identified from PubMed, EMBASE, Cochrane Library, Wanfang Data, and China National Knowledge Infrastructure (January 1, 1998–2016). A total of 19 studies were included. The primary efficacy endpoint was AF recurrence within 12 months, which significantly improved using CF-sensing catheters compared with using NCF-sensing catheters [31.1% vs. 40.5%; risk ratio (RR)=0.82; 95% confidence interval (CI), 0.73–0.93; p<0.05]. Further, the acute PV reconnection (10.1% vs. 24.2%; RR=0.45; 95% CI, 0.32–0.63; p<0.05) and incidence of major complications (1.8% vs. 3.1%; OR=0.59; 95% CI, 0.37–0.95; p<0.05) significantly improved using CF-sensing catheters compared with using NCF-sensing catheters. Procedure parameters such as procedure duration [mean difference (MD)=-28.35; 95% CI, -39.54 to -17.16; p<0.05], ablation time (MD=-3.8; 95% CI, -6.6 to -1.0; p<0.05), fluoroscopy duration (MD=-8.18; 95% CI, -14.11 to -2.24; p<0.05), and radiation dose (standard MD=-0.75; 95% CI, -1.32 to -0.18; p<0.05] significantly reduced using CF-sensing catheters. CF-sensing catheter ablation of AF can reduce the incidence of major complications and generate better outcomes compared with NCF-sensing catheters during the 12-month follow-up period.

Effects of Cardiac Resynchronization Therapy on Ventricular Electrical Remodeling in Patients With Heart Failure

Cardiac resynchronization therapy (CRT) reverses structural remodeling of the left ventricle. We investigated whether CRT reverses left-ventricular electrical remodeling.Eighty patients were enrolled and implanted with CRT-devices. Echocardiography and electrocardiography data were obtained from each patient prior to implantation and two years after implantation. At two years after implantation, the patients were classified into a responder group and a non-responder group based on echocardiography.Over the next 2 years, 75 patients completed follow-up, and 5 patients had died. Echocardiography results showed that 23 patients could be classified as non-responders and 52 as responders. Larger numbers of non-responders were diagnosed with either ischemic cardiomyopathy (ICM) or nonspecific intraventricular conduction delay (NICD). The intrinsic QRS duration was not changed in responders, patients with dilated cardiomyopathy, or in the patient categories of male and female. However, the intrinsic QRS duration was significantly prolonged in non-responders and patients with ischemic cardiomyopathy (P = 0.041). The mean left ventricular end-diastolic diameter in the responder group was significantly decreased by CRT (P < 0.05), while there was no significant change in intrinsic QRS duration.While CRT does not reduce the intrinsic QRS duration, it can delay negative ventricular electrical remodeling. Continuous CRT is necessary.

Comparison of standard and modified transvenous techniques for complex pacemaker lead extractions in the context of cardiac implantable electronic device-related infections: a 10-year experience.

AIMS Complete lead extraction of cardiac implantable electronic devices (CIED) for device-related infections remains a complex procedure for chronically implantated leads. We present data from a single-centre registry of consecutive patients with extractions over 10 years. METHOD AND RESULTS Patients were identified from the centres electronic database with CIED-related infections who underwent lead extraction using either the standard technique and equipment or a modified innovative transvenous lead technique extraction using an ablation catheter. Of 151 patients with CIED-related infections, not responding to simple manual traction to effect lead extraction, average age 65 ± 8 years (range 45-82), 64% being male, 75 underwent standard (S) extraction, and 76 underwent modified (M) extraction. Procedural, lead extraction, and fluoroscopy exposure times with S and M methods, respectively, were 65 ± 14 vs. 52 ± 6 min (P < 0.01), 56 ± 12 vs. 36 ± 8 min (P < 0.001), and 48 ± 12 vs. 31 ± 7 min (P < 0.001). Retrieval rates were numerically lower with the standard technique at 92 vs. 96% but did not achieve significance, with respective complication rates of 6.7 and 5.3%. CONCLUSION In our single-centre study, a modified extraction technique to retrieve leads for infections of CIEDs using a steerable ablation catheter has improved procedural parameters over the standard technique, without compromising clinical lead extraction success rates. This may be a promising approach for a future, prospective trial.

Left atrial appendage occlusion in atrial fibrillation for stroke prevention: A systemic review

BACKGROUND Atrial fibrillation (AF) is an arrthymia characterized by increased risk of ventricle arrthymias and thromboembolism especially ischemic stroke. Most thrombus originated in the left atrial appendage, thus left atrial occlusion (LAAO) may be an effective alternative for stroke prevention in atrial fibrillation. OBJECTIVE To assess the effect and safety of left atrial occlusion for stroke prevention in atrial fibrillation. METHODS AND RESULTS We searched Pub Med, CENTRAL in The Cochrane Library, Embase, CBM-Disk, CNKI for published trials, ClinicalTrials.gov, ISI Proceedings for conference abstracts, and WHO International Clinical Trial registration Platform for ongoing studies. The search results were extracted, and then the quality of included studies was assessed. By RevMan 5.3, meta analysis was used if there was low heterogeneity. Three randomized controlled clinical trials involving 1165 participants were included (percutaneous 1114 in 2 trials, surgical 51 in 1 trial). The current data suggest that left atrial occlusion may be as efficacious as warfarin in stroke prevention (RR 0.78 [0.33, 1.84]) and mortality reduction (RR 0.68 [0.40, 1.16]) for AF. CONCLUSION In contrast to warfarin left atrial occlusion with Watchman device may have the same effectivity in stroke reduction. Surgical LAAO may also get positive outcomes compared with warfarin, but owing to the small sample size the evidence is less powerful. Total outcomes of percutaneous and surgical LAAO support this approach.

Reference values of brachial-ankle pulse wave velocity according to age and blood pressure in a central Asia population

Background Brachial-ankle pulse wave velocity (baPWV), a direct measure of aortic stiffness, has increasingly become an important assessment for cardiovascular risk. The present study established the reference and normal values of baPWV in a Central Asia population in Xinjiang, China. Methods We recruited participants from a central Asia population in Xinjiang, China. We performed multiple regression analysis to investigate the determinants of baPWV. The median and 10th-90th percentiles were calculated to establish the reference and normal values based on these categories. Results In total, 5,757 Han participants aged 15–88 years were included in the present study. Spearman correlation analysis showed that age (r = 0.587, p < 0.001) and mean blood pressure (MBP, r = 0.599, p <0.001) were the major factors influencing the values of baPWV in the reference population. Furthermore, in the multiple linear regression analysis, the standardized regression coefficients of age (0.445) and MBP (0.460) were much higher than those of body mass index, triglyceride, and glycemia (-0.054, 0.035, and 0.033, respectively). In the covariance analysis, after adjustment for age and MBP, only diabetes was the significant independent determinant of baPWV (p = 0.009). Thus, participants with diabetes were excluded from the reference value population. The reference values ranged from 14.3 to 25.2 m/s, and the normal values ranged from 13.9 to 21.2 m/s. Conclusions This is the first study that has established the reference and normal values for baPWV according to age and blood pressure in a Central Asia population.

Idiopathic premature ventricular complexes originating from the distal great cardiac vein: Clinical, cardiac and electrophysiological characteristics and catheter ablation outcome

Aims: Although catheter ablation for idiopathic ventricular arrhythmia (VA) has been generally well‐established, VA originating from the great cardiac vein (GCV) may be clinically challenging due to its epicardial origin, proximity to coronary arteries and limited accessibility. The purpose of this study was to explore its electrophysiological characteristics and identify effective mapping/ablation strategies for idiopathic premature ventricular complexes (PVCs) originating from the GCV. Materials and methods: Between January 2013 to January 2018, 12 patients (who were diagnosed with PVCs originating from the GCV) among the 305 patients with idiopathic left ventricular outflow tract tachycardia were included. The origin of the ectopy was localized by mapping, the characteristics of the electrocardiogram (ECG) were analyzed, and all the patients with PVCs originating from GCV were treated by radiofrequency catheter ablation (RFCA). The safety and efficacy of RFCA were evaluated. Key findings: The origin of the ectopy was successfully localized in GCV for all 12 patients by mapping, and access to GCV via the coronary sinus was feasible. Successful RFCA was achieved in 11 of 12 patients (91.67% acute procedural success) without perioperative complications. During a median follow‐up of 12.6 ± 6.5 months, only one patient had recurrent VA (recurrence rate: 9.1%). Significance: ECG characteristics may be helpful for identifying patients with PVCs originating from the GCV. RFCA within the coronary venous system appears to be safe and effective for these patients, and should be considered when routine RFCA from the endocardium or aortic sinus of the Valsalva is not effective.

Ethnicity and anticoagulation management of hospitalized patients with atrial fibrillation in northwest China

The therapeutic management and health challenges caused by atrial fibrillation (AF) differ between different groups. The purpose of this study was to investigate the clinical features of patients hospitalized with AF and to explore the use of anticoagulation treatments in Han and Uygur patients in Xinjiang, northwest China. Data were collected from a retrospective descriptive study involving patients hospitalized at 13 hospitals in Xinjiang, China from Jul 1, 2014 to Jun 31, 2015. Anticoagulation management was measured according to guideline-recommended risk scores. A total of 4,181 patients with AF were included (mean age 69.5 ± 11.7 years, 41.4% females; 71.5% Han, 28.5% Uygur). The prevalence of AF in Uygur individuals may occur earlier than in Han individuals (mean age 64.9 vs 71.3, P < 0.001). Most of the hospitalized patients with AF had a high risk of stroke (CHA2DS2-VASc score ≥2; 80.6% Han vs 73.7% Uygur, P < 0.05); this risk was especially high in elderly patients. In AF patients, the application of anticoagulants according to the guidelines is far from expected, and the underutilization of anticoagulants exists in both ethnic groups.