BACKGROUNDThe congenital Long QT syndrome (LQTS) is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval, syncope, ventricular arrhythmias, and sudden death. The chromosome 7-linked type 2 congenital LQTS (LQT2) is caused by gene mutations in the human ether-a-go-go-related gene (HERG).

METHODSA Chinese family diagnosed with LQTS were screened for KCNQ1, HERG and SCN5A, using polymerase chain reaction (PCR), direct sequencing, and clong sequencing. We also investigated the mRNA expression of the HERG gene.

RESULTSWe identified a novel I414fs + 98X mutation in the HERG gene. The deletion mutation of 14-bp in the first transmembrane segment (S1) introduced premature termination codons (PTCs) at the end of exon 6. This mutation would result in a serious phenotype if the truncated proteins co-assembled with normal subunit to form the defective channels. But only the proband was symptomatic.

CONCLUSIONSWe found that the mRNA level of the HERG gene was significantly lower in I414fs + 98X carriers than in noncarriers. We found a novel I414fs + 98X mutation. The mRNA level supports that NMD mechanism might regulate the novel mutation.

Adult ; ERG1 Potassium Channel ; Ether-A-Go-Go Potassium Channels ; genetics ; Female ; Frameshift Mutation ; Humans ; Long QT Syndrome ; genetics ; RNA, Messenger ; analysis

In order to explore the potential influences of the disulfide bridge on the physical and chemical properties of PrP protein, the expressed recombinant human wild-type PrP protein was purified for using in an established redox process for the reduction and oxidation of the ethanethiol group within PrP. Sedimentation tests illustrated that redox process remarkably promoted the aggregation of recombinant PrP. Thioflavin T binding assay revealed an enhanced fibrillization of the recombinant human PrP after redox process. Far-UV circular dichroism demonstrated that the PrP treated with redox process showed a significant p-sheet rich structure. Furthermore, PrP-specific Western blot identified that the recombinant PrP after redox possessed stronger proteinase K-resistance. Those data indicates that the formation of the disulfide bridge induces the alteration of the secondary structure and enhances the progresses of aggregation and fibrillization of PrP protein.
Amyloid ; chemistry ; Endopeptidase K ; metabolism ; Humans ; Oxidation-Reduction ; Prions ; chemistry ; metabolism ; Protein Multimerization ; Protein Structure, Secondary ; Proteolysis ; Sulfhydryl Compounds ; chemistry

Reviewing important clinical trials in the field of arrhythmia in 2023,involving atrial fibrillation,pacing,and other aspects.Both the CIRDA-DOSE study and the EARLY-AF study affirmed the efficacy of cryoballoon ablation in treating atrial fibrillation,alter its progression to persistent atrial fibrillation.The MANIFEST-PF study examined the success rate and safety of pulse field ablation in atrial fibrillation,and the ADVENT study also confirmed its safety and effectiveness not inferior to conventional thermal ablation.In the LBBAP study,LBBAP reduced the occurrence of sustained VT/VF and new-onset atrial fibrillation compared to BVP.For patients with a high right ventricular pacing burden and reduced ejection fraction in pacemakers or ICDs,the BUDAPEST CRT upgrade study affirmed the benefits of upgrading to CRT-D.The DANPACE Ⅱ study showed that minimizing atrial pacing in patients with sinus node dysfunction does not reduce the incidence of atrial fibrillation.The IDE study demonstrated the safety of Aveir DR dual-chamber leadless pacemaker at 3 months post-operation,providing reliable atrial pacing and atrioventricular synchrony.The iSUSI study is a registry study of subcutaneous implantable cardioverter-defibrillators,finding similar inappropriate and appropriate shock rates in patients with and without heart failure.

Objective: To evaluate the effect of Li's catheter in cardiac resynchronization therapy (CRT) implantation. Methods: This study was a retrospective cohort study. Patients with indications for CRT implantation who visited the Department of Cardiology, Peking University People's Hospital from January 1, 2016 to January 1, 2022 were enrolled. Patients were divided into Li's catheter group (CRT implantation with Li's catheter) and control group (CRT implantation with the traditional method). The general clinical data of the patients were obtained through the electronic medical record system. Li's catheter is a new type of coronary sinus angiography balloon catheter independently developed by Dr. Li Xuebin (patent number: 201320413174.1). The primary outcome was the success rate of CRT device implantation, and the secondary outcomes included efficacy and safety parameters. Efficacy indicators included operation time, coronary sinus angiography time, left ventricular lead implantation time, X-ray exposure time, left ventricular lead threshold, and diaphragm stimulation. Safety outcomes included incidence of coronary sinus dissection, cardiac tamponade, and pericardial effusion. Results: A total of 170 patients were enrolled in this study, including 90 in Li's catheter group and 80 in control group. Age, male proportion of patients, proportion of patients with ischemic cardiomyopathy, hypertension, diabetes mellitus, chronic renal insufficiency, New York Heart Association (NYHA) functional classification, left ventricular ejection fraction, left ventricular end-diastolic diameter, proportion of left bundle branch block, and preoperative QRS wave width were similar between the two groups (all P>0.05). In Li's catheter group, 34 cases (37.8%) implanted with CRT defibrillators, and 28 cases (35.0%) implanted with CRT defibrillators in control group, the difference was not statistically significant (P=0.710). The success rate of CRT device implantation in Li's catheter group was 100% (90/90), which was significantly higher than that in control group (93.8%, 75/80, P=0.023).The operation time was 57.0 (52.0, 62.3) minutes, the time to complete coronary sinus angiography was 8.0 (6.0, 9.0) minutes, and the time of left ventricular electrode implantation was 8.0 (7.0, 9.0) minutes in Li's catheter group, and was 91.3 (86.3, 97.0), 18.0 (16.0, 20.0), 25.0 (22.0, 27.7) minutes respectively in control group, all significantly shorter in Li's catheter group (all P<0.05). The exposure time of X-ray was 15.0 (14.0, 17.0) minutes in Li's catheter group, which was also significantly shorter than that in control group (32.5 (29.0, 36.0) minutes, P<0.001). There was no coronary sinus dissection and cardiac tamponade in Li's catheter group, and 1 patient (1.1%) had diaphragmatic stimulation in Li's catheter group. In control group, 6 patients (6.7%) had coronary sinus dissection, and 1 patient (1.1%) developed pericardial effusion, and 3 patients (3.3%) had diaphragmatic stimulation. The incidence of coronary sinus dissection in Li's catheter group was significantly lower than that in control group (P=0.011). The postoperative left ventricular thresholds in Li's catheter group and control group were similar (1.80 (1.60, 2.38) V/0.5 ms vs. 1.80 (1.60, 2.40) V/0.5 ms, P=0.120). Conclusions: Use of Li's catheter is associated with higher success rate of CRT implantation, short time of coronary sinus angiography and left ventricular electrode implantation, reduction of intraoperative X-ray exposure, and lower incidence of coronary vein dissection in this patient cohort.
Cardiac Resynchronization Therapy/methods* ; Cardiac Tamponade/therapy* ; Catheters ; Heart Failure/therapy* ; Humans ; Male ; Pericardial Effusion ; Retrospective Studies ; Stroke Volume ; Treatment Outcome ; Ventricular Function, Left

Objective: For patients with paroxysmal atrial fibrillation, superior vena cava isolation on the basis of pulmonary vein isolation may further improve the long-term success rate of radiofrequency ablation. We aimed to explore the efficacy and safety of superior vena cava isolation by high-power and short-duration (HPSD) ablation plus conventional radiofrequency ablation (RA) in patients with paroxysmal atrial fibrillation. Methods: It was a prospective randomized controlled study. From January 1, 2019 to June 1, 2020, 180 patients who underwent radiofrequency ablation for paroxysmal atrial fibrillation in our center were consecutively screened. Patients were eligible if there was a trigger potential and the muscle sleeve length was greater than 3 cm. A total of 60 eligible patients were finally included and randomly divided into HPSD group (HPSD plus RA) and common power and duration (CPD) group (CPD plus RA) by random number table method (n=30 in each group). Efficacy was evaluated by ablation points, isolation time and ablation time. Safety was evaluated by the incidence of POP, cardiac tamponade, phrenic nerve injury, sinoatrial node injury and all-cause. Results: Superior vena cava isolation was achieved by 14 (13, 15) points in the HPSD group, which was significantly less than that in the CPD group (20(18, 22), P<0.001). The superior vena cava isolation time was 8 (7, 9) minutes in the HPSD group, which was significantly shorter than in the CPD group (17(14, 20) minutes, P<0.001). The average ablation time significantly shorter in HPSD group than in CPD group (78.0(71.1, 80.0) s vs. 200(167.5, 212.5)s, P<0.001). The average impedance drop was more significant in the HPSD group than in the CPD group (20.00(18.75, 21.00)Ω (and the percentage of impedance drop was 15%) vs. 12.00(11.75, 13.25)Ω (the percentage of impedance decrease was 12%), P<0.001). There was 1 POP (3.3%) in the HPSD group, and 3 POPs (10.0%) in the CPD group (P>0.05). There was no cardiac tamponade, phrenic nerve injury, sinoatrial node injury and death in both groups. Conclusions: HPSD technique for the isolation of superior vena cava is safe and effective in patients with paroxysmal atrial fibrillation undergoing conventional radiofrequency ablation.
Humans ; Atrial Fibrillation/surgery* ; Vena Cava, Superior/surgery* ; Prospective Studies ; Treatment Outcome ; Radiofrequency Ablation

Objective: To analyze the feasibility and safety of bridge therapy with active fixed electrodes connected to external permanent pacemakers (AFLEP) for patients with infective endocarditis after lead removal and before permanent pacemaker implantation. Methods: A total of 44 pacemaker-dependent patients, who underwent lead removal due to infective endocarditis in our center from January 2015 to January 2020, were included. According to AFLEP or temporary pacemaker option during the transition period, patients were divided into AFLEP group or temporary pacemaker group. Information including age, sex, comorbidities, indications and types of cardial implantable electionic device (CIED) implantation, lead age, duration of temporary pacemaker or AFLEP use, and perioperative complications were collected through Haitai Medical Record System. The incidence of pacemaker perception, abnormal pacing function, lead perforation, lead dislocation, lead vegetation, cardiac tamponade, pulmonary embolism, death and newly infection of implanted pacemaker were compared between the two groups. Pneumothorax, hematoma and the incidence of deep vein thrombosis were also analyzed. Results: Among the 44 patients, 24 were in the AFLEP group and 20 in the temporary pacemaker group. Age was younger in the AFLEP group than in the temporary pacemaker group (57.5(45.5, 66.0) years vs. 67.0(57.3, 71.8) years, P=0.023). Male, prevalence of hypertension, diabetes mellitus, chronic renal dysfunction and old myocardial infarction were similar between the two groups (all P>0.05). Lead duration was 11.0(8.0,13.0) years in the AFLEP group and 8.5(7.0,13.0) years in the temporary pacemaker group(P=0.292). Lead vegetation diameter was (8.2±2.4)mm in the AFLEP group and (9.1±3.0)mm in the temporary pacemaker group. Lead removal was successful in all patients. The follow-up time in the AFLEP group was 23.0(20.5, 25.5) months, and the temporary pacemaker group was 17.0(14.5, 18.5) months. In the temporary pacemaker group, there were 2 cases (10.0%) of lead dislocation, 2 cases (10.0%) of sensory dysfunction, 2 cases (10.0%) of pacing dysfunction, and 2 cases (10.0%) of death. In the AFLEP group, there were 2 cases of abnormal pacing function, which improved after adjusting the output voltage of the pacemaker, there was no lead dislocation, abnormal perception and death. Femoral vein access was used in 8 patients (40.0%) in the temporary pacemaker group, and 4 patients developed lower extremity deep venous thrombosis. There was no deep venous thrombosis in the AFLEP group. The transition treatment time was significantly longer in the AFLEP group than in the temporary pacemaker group (19.5(16.0, 25.8) days vs. 14.0(12.0, 16.8) days, P=0.001). During the follow-up period, there were no reinfections with newly implanted pacemakers in the AFLEP group, and reinfection occurred in 2 patients (10.0%) in the temporary pacemaker group. Conclusions: Bridge therapy with AFLEP for patients with infective endocarditis after lead removal and before permanent pacemaker implantation is feasible and safe. Compared with temporary pacemaker, AFLEP is safer in the implantation process and more stable with lower lead dislocation rate, less sensory and pacing dysfunction.
Humans ; Male ; Bridge Therapy ; Feasibility Studies ; Pacemaker, Artificial ; Endocarditis, Bacterial/etiology* ; Electrodes ; Device Removal

Objective: To investigate the efficacy and safety of infliximab (IFX) therapy for children with Kawasaki disease. Methods: Sixty-eight children with Kawasaki disease who received IFX therapy in Children's Hospital of Fudan University from January 2014 to April 2021 were enrolled. The indications for IFX administration, changes in laboratory parameters before and after IFX administration, response rate, drug adverse events and complications and outcomes of coronary artery aneurysms (CAA) were retrospectively analyzed. Comparisons between groups were performed with unpaired Student t test or Mann-Whitney U test or chi-square test. Results: Among 68 children with Kawasaki disease, 52 (76%) were males and 16 (24%) were females. The age of onset was 2.1 (0.5, 3.8) years. IFX was administered to: (1) 35 children (51%) with persistent fever who did not respond to intravenous immunoglobulin (IVIG) or steroids, 28 of the 35 children (80%) developed CAA before IFX therapy; (2) 32 children (47%) with continuous progression of CAA; (3) 1 child with persistent arthritis. In all cases, IFX was administered as an additional treatment (the time from the onset of illness to IFX therapy was 21 (15, 30) days) which consisted of second line therapy in 20 (29%), third line therapy in 20 (29%), and fourth (or more) line therapy in 28 (41%). C-reactive protein (8 (4, 15) vs. 16 (8, 43) mg/L, Z=-3.38, P=0.001), serum amyloid protein A (17 (10, 42) vs. 88 (11, 327) mg/L, Z=-2.36, P=0.018) and the percentage of neutrophils (0.39±0.20 vs. 0.49±0.21, t=2.63, P=0.010) decreased significantly after IFX administration. Fourteen children (21%) did not respond to IFX and received additional therapies mainly including steroids and cyclophosphamide. There was no significant difference in gender, age at IFX administration, time from the onset of illness to IFX administration, the maximum coronary Z value before IFX administration, and the incidence of systemic aneurysms between IFX-sensitive group and IFX-resistant group (all P>0.05). Infections occurred in 11 cases (16%) after IFX administration, including respiratory tract, digestive tract, urinary tract, skin and oral infections. One case had Calmette-Guérin bacillus-related adverse reactions 2 months after IFX administration. All of these adverse events were cured successfully. One child died of CAA rupture, 6 children were lost to follow up, the remaining 61 children were followed up for 6 (4, 15) months. No CAA occurred in 7 children before and after IFX treatment, while CAA occurred in 54 children before IFX treatment. CAA regressed in 23 (43%) children at the last follow-up, and the diameter of coronary artery recovered to normal in 10 children. Conclusion: IFX is an effective and safe therapeutic choice for children with Kawasaki disease who are refractory to IVIG or steroids therapy or with continuous progression of CAA.
Child ; Coronary Aneurysm/etiology* ; Female ; Humans ; Immunoglobulins, Intravenous/therapeutic use* ; Infant ; Infliximab/adverse effects* ; Male ; Mucocutaneous Lymph Node Syndrome/drug therapy* ; Retrospective Studies