Objective:To investigate the short-term efficacy and safety of cardiac contractility modulation (CCM) in patients with heart failure.Methods:This was a cross-sectional study of patients with heart failure who underwent CCM placement at the First Affiliated Hospital of Xinjiang Medical University from February to June 2022. With a follow-up of 3 months, CCM sensation, impedance, percent output, and work time were monitored, and patients were compared with pre-and 3-month postoperative left ventricular ejection fraction (LVEF) values, and 6-minute walk test distance and New York Heart Association (NYHA) cardiac function classification, and the occurrence of complications was recorded.Results:CCM was successfully implanted in all 9 patients. Seven(7/9) of them were male, aged (56±14) years, 3 patients had ischaemic cardiomyopathy and 6 patients had dilated cardiomyopathy. At 3-month postoperative follow-up, threshold was stable, sense was significantly lower at follow-up than before (right ventricle: (16.3±7.0) mV vs. (8.2±1.1) mV, P<0.05; local sense: (15.7±4.9) mV vs. (6.7±2.5) mV, P<0.05), and impedance was significantly lower at follow-up than before (right ventricle (846±179) Ω vs. (470±65) Ω, P<0.05, local sense: (832±246) Ω vs. (464±63) Ω, P<0.05). The CCM output percentage was (86.9±10.7) %, the output amplitude was (6.7±0.4) V, and the daily operating time was (8.6±1.0) h. LVEF was elevated compared to preoperative ((29.4±5.2) % vs. (38.3±4.3) %, P<0.05), the 6-minute walk test was significantly longer than before ((96.8±66.7)m vs. (289.3±121.7)m, P<0.05). No significant increase in the number of NYHA Class Ⅲ-Ⅳ patients was seen (7/9 vs. 2/9, P>0.05). The patient was not re-hospitalised for worsening heart failure symptoms, had no malignant arrhythmic events and experienced significant relief of symptoms such as chest tightness and shortness of breath. No postoperative complications related to pocket hematoma, pocket infection and rupture, electrode detachment, valve function impairment, pericardial effusion, or cardiac perforation were found. Conclusions:CCM has better short-term safety and efficacy in patients with heart failure.

AIM:To explore the expression of calcium binding and coiled-coil domain 2(CALCOCO2)in ani-mal models of atrial fibrillation(AF)and its role and mechanism in reversing atrial remodeling in AF mice.METHODS:Twelve rats and 12 mice were randomly divided into the following 2 groups(n=6 each):saline control group(saline group)and angiotensin Ⅱ(Ang Ⅱ)-induced AF group(Ang Ⅱ group).Western blot and immunohistochemistry(IHC)were used to detect CALCOCO2 expression in rat and mouse atrial muscle tissues.Another 24 mice were randomly divided into 4 groups(n=6 each):saline-oeNC,Ang Ⅱ-oeNC,saline-oeCALCOCO2,and Ang Ⅱ-oeCALCOCO2.An adeno-asso-ciated virus was used to induce CALCOCO2 overexpression in mouse atrial myocardium.Subsequently,transthoracic echocardiography and intracardiac electrophysiological testing were used to compare mouse cardiac function among the 4 groups.Western blot and TUNEL staining were also used to evaluate the effect of CALCOCO2 on apoptosis of cardiomyo-cytes in AF models.Additionally,IHC was used to assess the effect of CALCOCO2 on the levels of oxidative stress-related proteins[NADPH oxidase 2(NOX2)and NOX4]and fibrosis-related proteins[collagen type Ⅰ(Col Ⅰ),connexin 40(Cx40)and α-smooth muscle actin(α-SMA)]in AF atrial myocardium.RESULTS:The CALCOCO2 protein level in the atrial myocardium of rats and mice was significantly decreased in Ang Ⅱ group compared with saline group,as detected by Western blot and IHC(0.19±0.01 vs 0.32±0.03 for rats,0.37±0.10 vs 1.00±0.10 for mice,P<0.01).Compared with Ang Ⅱ-oeNC group,the mice in Ang Ⅱ-oeCALCOCO2 group exhibited decreased left atrial inner diameter,shorter AF duration,and increased ejection fraction(P<0.05).Semi-quantitative analysis of TUNEL staining revealed a signifi-cantly decreased apoptosis rate of mouse atrial myocytes in Ang Ⅱ-oeCALCOCO2 group compared with Ang Ⅱ-oeNC group(0.30±0.06 vs 0.61±0.03,P<0.01),which was consistent with the Western blot trend of apoptosis-related proteins such as BAX(1.94±0.34 vs 3.14±0.34,P<0.05)and cleaved caspase-3(2.19±0.41 vs 3.52±0.55,P<0.05).The semi-quantitative results of IHC and immunofluorescence revealed significantly increased levels of oxidative stress-related pro-teins(NOX2 and NOX4)and fibrosis-related proteins(Col Ⅰ and α-SMA),as well as decreased Cx40 levels,in Ang Ⅱ-oeNC group compared with saline-oeNC group.However,the expression levels of these proteins were significantly re-versed after CALCOCO2 overexpression(all P<0.05).CONCLUSION:Overexpression of CALCOCO2 reverses AF-in-duced electrical and structural remodeling by inhibiting the oxidative stress,apoptosis and fibrosis in mouse atrial tissues.

Objectives:This study aims to explore the effects of pioglitazone on the attenuation of ventricular arrhythmias(VAs)induced by β1-adrenergic receptor autoantibodies(β1AAb)and its potential mechanisms. Methods:48 SD rats were uniformly randomly divided into four groups using number table:control group received vehicle injection,β1AAb group received back multi-point injection of β1AR-ECLⅡ antigen peptide with adjuvant,2 mg/(kg·time),pioglitazone group received pioglitazone gavage for 2 weeks after 8 weeks of immunization,4 mg/(kg·d),and GW9662 group received pioglitazone+GW9662 intraperitoneal injection for 2 weeks after 8 weeks of immunization,1 mg/(kg·d).Powerlab recorded electrocardiograms and blood collection every 2 weeks.Baseline and week 10 echocardiography were recorded,followed by electrophysiology,histopathology,immunohistochemical staining,and electron microscopy examination after 10 weeks. Results:Compared to control group,β1AAb group showed a higher incidence of ventricular arrhythmias,shorter ventricular effective refractory period(VERP),longer action-recovery interval(ARI),lower left ventricular ejection fraction(LVEF)and left ventricular fractional shortening(LVFS),lower positive staining area ratio of glucose transporter 1(GLUT1)and carnitine palmitoyltransferase 1a(CPT1a),all P＜0.05.Mitochondrial morphology abnormalities and network damage were also significantly observed(P＜0.05).In contrast to β1AAb group,pioglitazone group showed a reduced incidence of ventricular arrhythmias,prolonged VERP,shortened ARI,recovered LVEF and LVFS,increased the positive staining area ratio of GLUT1 and CPT1a,all P＜0.05.Improvement was observed in mitochondrial morphology abnormalities and network damage(P＜0.05).Compared to pioglitazone group,GW9662 group exhibited a higher incidence of ventricular arrhythmias,shorter VERP,and longer ARI,lower LVEF and LVFS,lower positive staining area ratio of GLUT1 and CPT1a,all P＜0.05.Mitochondrial morphology abnormalities and network damage did not recover(P＜0.05). Conclusions:Pioglitazone can reduce VAs induced by β1AAb,improve ventricular electrical conduction and activation recovery time heterogeneity,and mitigate ventricular remodeling caused by β1AAb at the tissue pathology level,accompanied by upregulation of ventricular cardiomyocyte glucose and lipid transport channel proteins and repair of damaged mitochondrial networks.

Objective:To explore the related risk factors for systemic embolism (SE) in patients aged≥75 years with non-valvular atrial fibrillation (NVAF).Methods:A case-control study. NVAF patients aged≥75 years who were hospitalized at the First Affiliated Hospital of Xinjiang Medical University from October 2018 to October 2020 were divided into no SE ( n=1 127) and SE ( n=433) groups according to the occurrence of SE after NVAF. Multivariate logistic regression was used to analyze SE-related factors in patients with NVAF without anticoagulation treatment. Results:In the multivariate model, the following factors were associated with an increased risk of SE in patients with NVAF: history of AF≥5 years [odds ratio ( OR)=2.75, 95% confidence interval ( CI) 1.98-3.82, P<0.01], lipoprotein(a)>300 g/L ( OR=2.07, 95% CI 1.50-2.84, P<0.01), apolipoprotein (Apo)B>1.2 g/L ( OR=1.91, 95% CI 1.25-2.93, P=0.003), left ventricular ejection fraction (LVEF) of 30%-49% ( OR=2.45, 95% CI 1.63-3.69, P<0.01), left atrial diameter>40 mm ( OR=1.54, 95% CI 1.16-2.07, P=0.003), and CHA 2DS 2-VASc score≥3 ( OR=15.14, 95% CI 2.05-112.13, P=0.01). ApoAI>1.6 g/L was negatively correlated with the occurrence of SE ( OR=0.28, 95% CI 0.15-0.51, P<0.01). Conclusions:History of AF≥5 years, lipoprotein(a)>300 g/L, elevated ApoB, left atrial diameter>40 mm, LVEF of 30%-49%, and CHA 2DS 2-VASC score≥3 are independent risk factors for SE whereas ApoAI>1.6 g/L is a protective factor against SE in patients with NVAF.

Hypertrophic obstructive cardiomyopathy (HOCM) is the most common type of hypertrophic cardiomyopathy, which is prone to left ventricular outflow obstruction and causes various adverse effects. It is also the main cause of sudden death in adolescents and athletes. Timely intervention is crucial for the prognosis of patients. Radiofrequency ablation has been widely used in the treatment of various arrhythmias, but it is still a new treatment method in HOCM. This article mainly reviews the clinical application progress of radiofrequency ablation in the treatment of HOCM patients.

Objective:To investigate the association between abnormal left atrial appendage function and thrombotic events in patients with non-valvular atrial fibrillation, and the independent risk factors affecting left atrial appendage function.Methods:Patients with non-valvular atrial fibrillation, who visited the Atrial Fibrillation Center of the First Affiliated Hospital of Xinjiang Medical University from June 1, 2019 to June 1, 2021, were selected. According to left atrial appendage flow velocity (LAAFV), they were divided into normal left atrial appendage function group (297 patients with LAAFV ≥ 40 cm/s) and abnormal left atrial appendage function group (85 patients with LAAFV<40 cm/s). Baseline data and transesophageal echocardiography images were collected from all the patients. The occurrence of thrombotic events was recorded. Univariate and multivariate unconditional logistic regression analyses were conducted to investigate the correlation between abnormal left atrial appendage function and the occurrence of thrombotic events.Results:There were significant differences in gender, type of atrial fibrillation, CHA 2DS 2-VASc score, anticoagulant therapy, total cholesterol, low-density lipoprotein cholesterol, international normalized ratio (INR), left atrial diameter, proportion of patients with right atrial enlargement, left ventricular ejection fraction, inner diameter, sum of inner diameter, depth, and sum of depth of all angles of the left atrial appendage, and incidence of thrombotic events between the two groups (all P<0.05). After adjusting for confounders, multivariate unconditional logistic regression analyses showed that abnormal left atrial appendage function was closely associated with thrombotic events (β=1.168 P=0.002), and left atrial diameter ( OR=1.084, 95% CI 1.019-1.153, P=0.011) and persistent atrial fibrillation ( OR=2.323, 95% CI 1.226-4.403, P=0.010) were independent risk factors affecting left atrial appendage function. Conclusions:Abnormal left atrial appendage function is closely associated with thrombosis. The left atrial diameter and persistent atrial fibrillation were independent risk factors affecting left atrial appendage function.

Objective:The underlying causes of unexplained syncope and palpitations are difficult to determine in clinical practice. This study was designed to investigate the value of the insertable cardiac monitor (ICM) for the diagnosis of the unexplained syncope and palpitations.Methods:A total of 184 patients with syncope or palpitations due to unexplained reasons were enrolled in the First Affiliated Hospital of Xinjiang Medical University (144 patients with unexplained syncope and 40 patients with unexplained palpitations) from October 2015 to October 2019. Among them, 99 patients (77 patients with unexplained syncope and 22 patients with unexplained palpitations) were received ICM implantation (the ICM implanted group) and 85 patients (67 patients with unexplained syncope and 18 patients with unexplained palpitations) were not (the non-ICM implanted group). The patients in the ICM implanted group were followed up once every 3 months until the occurrence of syncope or palpitations. During follow-up, the electrocardiograph (ECG) data recorded by ICM were collected and analyzed retrospectively. The patients in the non-ICM implanted group underwent routine follow-up.Results:The follow-up time of the ICM implanted group was (29.3±9.3) months, and the follow-up time of the non-ICM implanted group was (27.2±10.4) months. The total detection rate (syncope and palpitations) in the implanted ICM group was much higher than that in the non-ICM implanted group (38.4% vs. 3.5%, P<0.001), with syncope detection rate of 40.3% in the implanted ICM group and 3.0% in the non-ICM implanted group ( P<0.001), and palpitation detection rate of 31.8% in the implanted ICM group and 5.6% in the non-ICM implanted group ( P<0.05). Conclusions:Application of ICM greatly improved the diagnosis rate of patients with unexplained syncope and palpitations. It is recommended for patients with unexplained syncope and palpitations to implant ICM as soon as possible.

Objective:To investigate the relationship between indicators of carotid atherosclerosis and onset of ischemic stroke in patients with non-valvular atrial fibrillation (NVAF).Methods:This is a case-control study, a total of 397 NVAF patients with newly diagnosed ischemic stroke (case group) and 3 038 NVAF patients without ischemic stroke (control group) from January 2015 to December 2017 were included in the study. Differences in general clinical features and carotid atherosclerosis indexes between the two groups were compared. Univariate and multivariate logistic regressions were used to analyze the correlation between carotid atherosclerosis indexes and ischemic stroke.Results:Proportions of patients with carotid intima thickening, carotid plaque, stable plaque, unstable plaque, and moderate to severe stenosis were higher in the ischemic stroke group than those in the control group (82.1% vs. 64.4%, 69.3% vs. 50.3%, 43.6% vs. 30.6%, 25.7% vs. 19.7%, and 7.3% vs. 4.0%, respectively, all P <0.05). After adjustment of age, gender, heart failure, hypertension, low density lipoprotein -cholesterol and drug use, multivariate analyses showed that subjects with carotid intima thickening, carotid plaque, stable plaque, unstable plaque, moderate to severe stenosis had 1.766, 2.111, 1.892, 2.256 and 1.824 times the risk for the development of ischemic stroke compared with the subjects without any carotid atherosclerosis indicators. Conclusion:Carotid atherosclerosis, especially with unstable carotid plaque, is associated with ischemic stroke in patients with NVAF.

Objective: Present study analyzed the association betwen the postassium voltage-gated channel KQT-like subfamily member 1 gene (KCNQ1) mutation and the clinical and the electrocardiographic features in 2 pedigrees with congenital long QT syndrome type 1 (LQT1) in Xinjiang Uygur Autonomous Region. Methods: Three family members were diagnosed as LQT1 patients in 2 Uygur congenital LQT1 families, these 3 LQT1 patients served as long QT group, 24 Uygur healthy volunteers served as control group. Electrocardiogram (ECG) and the gene detection were applied to compare the ECG and molecular genetic features between the long QT group and control group, and to explore the relationship between the KCNQ1 gene mutation and the clinical and the electrocardiographic features in these 2 families with congenital long QT syndrome type 1. Results: The LQT1 was diagnosed in 3 cases of the 2 pedigrees. The common features of ECG were QTc>480 ms, prolonged ST segment, and delayed T wave. The gene test evidenced a polymorphism of KCNQ1 gene exon 13:47G➝A(R16R). The mutation of 133G➝A9(G45S) of exon 16 resulted in the change of the original glycine (G) to serine (s). The ECG of the control group were normal, and there were no KCNQ1 gene mutations in control group. Conclusion The exon sequencing results of KCNQ1 gene in 2 Xinjiang Uygur congenital long LQT1 families showed that exon16 missense changes (133G to A (G45S)) can lead to amino acid mutation, this mutation may be a pathogenic mutation. Subsequent validation of the expanded sample will provide a reference for revealing the relationship between the KCNQ1 gene and the pathogenesis of LQT1.

Objective To evaluate the association between LDL-C and ischemic stroke in patients with nonvalvular atrial fibrillation (AF).Method A total of 2 470 patients with nonvalvular AF were included in the present study.The clinical data and laboratory examination results of the patients in the hospital were collected.The subjects were either divided into the ischemic stroke history (n =560),and non-ischemic stroke history groups (n =1 910),or divided into the low-middle risk (n =566) and high risk groups (n =1 904) based on CHA2 DS2-VASc score.Results There were significant differences in the proportion of Han,the ratio of gender,age,hemoglobin,hematocrit,ALT,serum uric acid,HDL-C and LDL-C between the patients with ischemic stroke history and without (all P ＜ 0.05).Similarly,there were significant differences in the proportion of Han,the ratio of gender,age,white blood cell count,hemoglobin,hematocrit,platelet count,ALT,albumin,TG and LDL-C between subjects in the low-middle risk group and those in the high risk group (all P ＜ 0.05).A logistical regression analysis showed that LDL-C was an independent risk factor for both the ischemic stroke history (OR 2.089,95％ CI 1.860-2.347,P ＜0.05),and future ischemic stroke risk (OR 1.270,95％ CI 1.079-1.494,P ＜ 0.05) in patients with nonvalvular AF.Conclusion LDL-C is associated with ischemic stroke in patients with nonvalvular AF,and it is also an independent risk factor for future ischemic stroke in these patients.