Objective To investigate the application value of late gadolinium enhancement(LEG)at cardiac MRI in predicting ventricular arrhythmia(VA)events in patients after implantation of ICD.Methods A retrospective analysis was performed on 16 patients at high risk of sudden cardi-ac death after ICD implantation and LEG examination in the First and the Sixth Medical Centers of Chinese PLA General Hospital from June 2020 to March 2024.According the occurrence of VA events receiving appropriate ICD therapy during the follow-up period,they were divided into post-operative VA group(7 cases)and non-VA group(9 cases).The correlation of clinical baseline fea-tures and LEG features with VA events was analyzed.Results The ratios of transmural enhance-ment and myocardial medium enhancement were obviously higher in the VA group than the non-VA group(71.4％vs 11.1％,P=0.035;85.7％vs 22.2％,P=0.041).Multivariate logistic regres-sionanalysis showed that transmural enhancement(OR=5.000,95％CI:0.150-166.589,P=0.368)and myocardial medium enhancement(OR=7.000,95％CI:0.217-226.005,P=0.272)were not independent factors influencing VA occurrence.ROC curve analysis indicated that the combined prediction of transmural enhancement and myocardial media enhancement and the pre-diction of transmural enhancement alone had better diagnostic efficacy(P＜0.05).Conclusion LEG has clinical value in predicting postoperative VA events in patients after ICD implantation.

Congenital long QT syndrome (LQTS) is a life-threatening ion channelopathy caused by mutations in genes encoding specific ion channels, which can result in malignant arrhythmia of the torsades de pointes type. LQTS type 4 represents less than 1% of inherited LQTS cases, in contrast to the 90% attributable to types 1-3, it is specifically caused by loss-of-function mutations in the membrane-binding domain of ANK2. Here, a novel ANK2 variant ( ANK2c 2245 A>C, resulting in p.Lys749Gln) associated with LQTS type 4 and Wolff-Parkinson-White syndrome was identified in a previously healthy 61-year-old male patient who suffered paroxysmal palpitations and pre-syncope due to recurrent torsades de pointes.

Congenital long QT syndrome (LQTS) is a life-threatening ion channelopathy caused by mutations in genes encoding specific ion channels, which can result in malignant arrhythmia of the torsades de pointes type. LQTS type 4 represents less than 1% of inherited LQTS cases, in contrast to the 90% attributable to types 1-3, it is specifically caused by loss-of-function mutations in the membrane-binding domain of ANK2. Here, a novel ANK2 variant ( ANK2c 2245 A>C, resulting in p.Lys749Gln) associated with LQTS type 4 and Wolff-Parkinson-White syndrome was identified in a previously healthy 61-year-old male patient who suffered paroxysmal palpitations and pre-syncope due to recurrent torsades de pointes.

Objective To summarize the results of different perioperative anticoagulation protocols for elderly patients with atrial fibrillation(AF)undergoing catheter radiofrequency ablation in our center.Methods A total of 197 elderly AF patients undergoing catheter radiofrequency ablation by a single operator in the First and Sixth Medical Centers of Chinese PLA General Hospital from January 2021 to December 2023 were retrospectively recruited,and the results of relevant exami-nations were collected.Based on the use of different direct oral anticoagulants,they were divided into dabigatran(n=125)and rivaroxaban(n=72)groups.During the procedure,the appropriate dose of unfractionated heparin was administered according to the initial activated clotting time(ACT)with a self-made formula.The time and rate of ACT were recorded,and perioperative ad-verse reactions such as bleeding and thrombosis were observed.Results There were no statistical differences between the two groups in baseline data,including age,gender,BMI,medical history,CHA2DS2-VASc score,HAS-BLED score,and left atrial anteroposterior diameter(P＞0.05).The baseline ACT value was obviously shorter(149.73+23.52 s vs 157.91±24.58 s,P=0.032),the initial heparin dose was significantly higher(0.71±0.12 mg/kg vs 0.65±0.13 mg/kg,P=0.031),and the rate of ACT reaching the target within 15 min was notably lower(60％vs 74％,P＜0.05)in the dabigatran group than the rivaroxaban group.But no significant difference was observed in the rate of ACT reaching the target in 45 min after additional heparin administration according to the formula(86％vs 88％,P＞0.05).The dabigatran group used higher dose of heparin during the procedure than the rivaroxaban group(0.99±0.30 mg/kg vs 0.85±0.31 mg/kg,P=0.009).Peri-cardial effusion was observed in one patient of the rivaroxaban group,and hematoma at the site of femoral vein puncture was seen in one patients of the dabigatran group in 1 d after procedure,which was treated surgically.No other severe complications occurred.Conclusion For elderly pa-tients with AF undergoing catheter ablation therapy,continuous perioperative anticoagulation and individualized application of unfractionated heparin based on initial ACT value can rapidly achieve ACT targets and improve anticoagulation efficacy.

Objective To summarize the results of different perioperative anticoagulation protocols for elderly patients with atrial fibrillation(AF)undergoing catheter radiofrequency ablation in our center.Methods A total of 197 elderly AF patients undergoing catheter radiofrequency ablation by a single operator in the First and Sixth Medical Centers of Chinese PLA General Hospital from January 2021 to December 2023 were retrospectively recruited,and the results of relevant exami-nations were collected.Based on the use of different direct oral anticoagulants,they were divided into dabigatran(n=125)and rivaroxaban(n=72)groups.During the procedure,the appropriate dose of unfractionated heparin was administered according to the initial activated clotting time(ACT)with a self-made formula.The time and rate of ACT were recorded,and perioperative ad-verse reactions such as bleeding and thrombosis were observed.Results There were no statistical differences between the two groups in baseline data,including age,gender,BMI,medical history,CHA2DS2-VASc score,HAS-BLED score,and left atrial anteroposterior diameter(P＞0.05).The baseline ACT value was obviously shorter(149.73+23.52 s vs 157.91±24.58 s,P=0.032),the initial heparin dose was significantly higher(0.71±0.12 mg/kg vs 0.65±0.13 mg/kg,P=0.031),and the rate of ACT reaching the target within 15 min was notably lower(60％vs 74％,P＜0.05)in the dabigatran group than the rivaroxaban group.But no significant difference was observed in the rate of ACT reaching the target in 45 min after additional heparin administration according to the formula(86％vs 88％,P＞0.05).The dabigatran group used higher dose of heparin during the procedure than the rivaroxaban group(0.99±0.30 mg/kg vs 0.85±0.31 mg/kg,P=0.009).Peri-cardial effusion was observed in one patient of the rivaroxaban group,and hematoma at the site of femoral vein puncture was seen in one patients of the dabigatran group in 1 d after procedure,which was treated surgically.No other severe complications occurred.Conclusion For elderly pa-tients with AF undergoing catheter ablation therapy,continuous perioperative anticoagulation and individualized application of unfractionated heparin based on initial ACT value can rapidly achieve ACT targets and improve anticoagulation efficacy.

Objective To investigate the application value of late gadolinium enhancement(LEG)at cardiac MRI in predicting ventricular arrhythmia(VA)events in patients after implantation of ICD.Methods A retrospective analysis was performed on 16 patients at high risk of sudden cardi-ac death after ICD implantation and LEG examination in the First and the Sixth Medical Centers of Chinese PLA General Hospital from June 2020 to March 2024.According the occurrence of VA events receiving appropriate ICD therapy during the follow-up period,they were divided into post-operative VA group(7 cases)and non-VA group(9 cases).The correlation of clinical baseline fea-tures and LEG features with VA events was analyzed.Results The ratios of transmural enhance-ment and myocardial medium enhancement were obviously higher in the VA group than the non-VA group(71.4％vs 11.1％,P=0.035;85.7％vs 22.2％,P=0.041).Multivariate logistic regres-sionanalysis showed that transmural enhancement(OR=5.000,95％CI:0.150-166.589,P=0.368)and myocardial medium enhancement(OR=7.000,95％CI:0.217-226.005,P=0.272)were not independent factors influencing VA occurrence.ROC curve analysis indicated that the combined prediction of transmural enhancement and myocardial media enhancement and the pre-diction of transmural enhancement alone had better diagnostic efficacy(P＜0.05).Conclusion LEG has clinical value in predicting postoperative VA events in patients after ICD implantation.

Objective To develop an intelligent model for differential diagnosis of atrioventricular nodal re-entrant tachycardia(AVNRT)and atrioventricular re-entrant tachycardia(AVRT)using 12-lead wearable electrocardiogram devices.Methods A total of 356 samples of 12-lead supraventricular tachycardia(SVT)electrocardiograms recorded by wearable devices were randomly divided into training and validation sets using 5-fold cross validation to establish the intelligent classification model,and 101 patients with the diagnosis of SVT undergoing electrophysiological studies and radiofrequency ablation from October,2021 to March,2023 were selected as the testing set.The changes in electrocardiogram parameters before and during induced tachycardia were compared.Based on multiscale deep neural network,an intelligent diagnosis model for classifying SVT mechanisms was constructed and validated.The 3-lead electrocardiogram signals from Ⅱ,Ⅲ,and V1 were extracted to build new classification models,whose diagnostic efficacy was compared with that of the 12-lead model.Results Of the 101 patients with SVT in the testing set,68 were diagnosed with AVNRT and 33 were diagnosed with AVRT by electrophysiological study.The pre-trained model achieved a high area under the precision-recall curve(0.9492)and F1 score(0.8195)for identifying AVNRT in the validation set.The total F1 scores of the lead Ⅱ,Ⅲ,V1,3-lead and 12-lead intelligent diagnostic models in the testing set were 0.5597,0.6061,0.3419,0.6003 and 0.6136,respectively.Compared with the 12-lead classification model,the lead-Ⅲ model had a net reclassification index improvement of-0.029(P=0.878)and an integrated discrimination index improvement of-0.005(P=0.965).Conclusion The intelligent diagnostic model based on multiscale deep neural network using wearable electrocardiogram devices has an acceptable accuracy for classifying SVT mechanisms.

Objective To observe the effect of different concentrations of glutamine(Gln)on the radiosensitivity of colorectal cancer HT-29 cells and explore the possible mechanism.Methods According to different Gln concentrations,HT-29 cells at logarithmical growth were divided into control group(2 mmol/L,as the basal medium concentration group)and experimental groups Ⅰ,Ⅱ and Ⅲ(4,6 and 8 mmol/L).After a 2-hour pre-treatment,all groups were exposed to 8 Gy irradiation of a Co-60 radiation source.CCK-8 assay and clonal formation assay were used respectively to explore the effects of different Gln concentrations on cell viability and cell radiosensitivity after irradiation.The level of reactive oxygen species(ROS)in each group was measured in 24 h after irradiation,and the apoptotic rate was detected with flow cytometry in 48 h after irradiation.The protein expression levels of Nrf2,HO-1,and cleaved-Caspase3 were determined by Western blotting.Results In 24 h after Gln intervention,the cell viability of experimental groups Ⅱ and Ⅲof non-irradiated HT-29 cells was significantly higher than that of the control group and of experimental group Ⅰ(P＜0.05).In 24 h after radiation,the cell viability of each experimental group was significantly higher than that of the control group(P＜0.05).In 14 d after radiation,there were more clone formation in each experimental group than the control group(P＜0.05).The ROS level was significantly lower in each experimental group than the control group in 24 h after radiation(P＜0.05).After 48 h of radiation,the apoptotic rate was notably lower in each experimental group than the control group(P＜0.05).The expression level of Nrf2 in the experimental group Ⅰ was higher than that of the control group(P＜0.05),those of Nrf2 and HO-1 in the experimental groups Ⅱ and Ⅲ were higher than those of the control group and experimental group Ⅰ(P＜0.05).While the expression of cleaved-Caspase3 in the experimental groups Ⅱ and Ⅲ was lower than the control group and experimental group Ⅰ(P＜0.05),and it in the experimental group Ⅲ was lower than that of experimental group Ⅱ(P＜0.05).Conclusion Gln can significantly reduce the radiosensitivity of HT-29 cells,which is associated with its reducing oxidative stress damage and reducing cell apoptosis.Our results suggest that Gln might be detrimental to radiation therapy in patients with colorectal cancer.

Hyperkalemia is one of the common ion metabolism disorders in clinical practice. Hyperkalemia is defined as serum potassium higher than 5.0 mmol/L according to the guidelines at home and abroad. Acute severe hyperkalemia can cause serious consequences, such as flaccid paralysis, fatal arrhythmia, and even cardiac arrest. The use of renin-angiotensin- aldosterone system inhibitors, β-blockers and diuretics, low-sodium and high-potassium diets, and the presence of related comorbidities increase the occurrence of hyperkalemia. Hyperkalemia risk exist in all clinical departments, but there is a lack of a standardization in the management of multi- department cooperation in hospital. Therefore, a number of domestic nephrology and cardiology department experts have discussed a management model for multi-department cooperation in hyperkalemia, formulating the management standard on hospital evaluation, early warning, diagnosis and treatment, and process. This can promote each department to more effectively participate in nosocomial hyperkalemia diagnosis and treatment, as well as the long-term management of chronic hyperkalemia, improving the quality of hyperkalemia management in hospital.

Objective To track and evaluate the implementation of the Radiation Shielding Requirements in Room of Radiotherapy Installations—Part 1: General Principle (GBZ/T 201.1–2007) among relevant personnel in medical radiation institutions, and to provide a scientific basis for revising the standard. Methods According to the Guidelines for Health Standards Tracking Evaluation (WS/T 536–2017) and the implementation protocol of standard evaluation, an online survey was conducted among 212 relevant workers from 146 medical radiation institutions across 18 provinces in China. The data were aggregated and analyzed with the use of Microsoft Excel 2010. Results A total of 215 questionnaires were returned, of which 212 were valid. Among the valid respondents, 77.8% believe that this standard is universally applied; 96.2% believe that this standard can meet work needs; 63.7% have participated in relevant training on this standard; 74.1% use this standard once or more per year; and 10.8% believe that this standard needs to be revised. Conclusion Medial radiation workers have a high rate of awareness of the basic information and content of the standard, but the understanding and application of the standard content need to be improved. We recommend that relevant departments further strengthen the promotion of and training on the standard, revise some content based on actual situation, and improve workers’ ability to use the standard.