Objective:This study aims to investigate the feasibility and safety of implanting leadless pacemakers in the low septum and its impact on cardiac electrical synchronization.Methods:A total of 36 patients who received leadless pacemaker implantation at Fuwai Central China Cardiovascular Hospital from January 2021 to August 2023 were included in this study.According to implantation sites of leadless pacemakers,patients were divided into mid-septal group(n=16)and low-septal group(n=20).The clinical characteristics and cardiac electrical synchronization were compared between the two groups.Results:There were 21 male patients,mean age was(68±13)years old.There was no statistical difference in the type of brady-arrhythmia between the two groups(P=0.73).There were 61 implant attempts in these 36 patients,and there was no significant difference in the number of attempts,procedure time,and pacemaker parameters between the two groups,but the average procedure time tended to be shorter in the low-septal group([84±37]minutes vs.[105±35]minutes,P=0.09).In terms of electrical synchronization,there was no statistical difference in QRS duration between the low-septal group and the mid-septal group([162.0±21.1]ms vs.[174.0±14.8]ms,P=0.20).There were no vascular puncture complications,cardiac perforation,or pericardial tamponade during the procedure.There were no complications and readmissions related to the leadless pacemaker during follow-up period.Conclusions:Our results show that the implantation of a leadless pacemaker in the low ventricular septum is safe and effective,has a similar impact on cardiac electrical synchronization as mid-septal pacing.

Objectives:This study aims to explore the impact of new-onset heart conduction block post transcatheter aortic valve replacement(TAVR)on the cardiac conduction status during 1-year follow-up.Methods:A total of 130 patients who completed TAVR surgery at Fuwai Central-China Cardiovascular Hospital from July 2019 to October 2022 were screened.Among them,56 cases with postoperative heart conduction block were selected for analysis.According to the degree of heart block,patients were divided into mild block group(n=36),moderate block group(n=9),and severe block group(n=11).The clinical characteristics and cardiac conduction conditions at 1-year follow-up between different groups were compared.Results:During a mean(8.5±4.1)months follow-up period,10(17.9%)patients had long-term atrioventricular conduction block,and 46(82.1%)patients had partial or complete recovery of heart block,with 28(50.0%)patients with completely recovered cardiac conduction.In the mild block group,22(61.1%)cases were completely recovered,9(25.0%)patients partly recovered,and 5(13.9%)cases uncovered.In the moderate block group,2(22.2%)cases were completely recovered,5(55.6%)patients partly recovered,and 2(22.2%)cases uncovered.Difference in long-term atrioventricular conduction block among three groups was statistically significant(P<0.001).The Kaplan-Meier curve shows that patients with moderate to severe heart block have a higher rate of long-term atrioventricular conduction block(86.1%vs.77.8%vs.72.7%,log-rank P=0.03).Cox multivariate analysis exhibited that old age(≥75 years old,HR=1.204,95%CI:1.051-1.525,P=0.041)and severe heart conduction block(HR=1.106,95%CI:1.100-1.616,P=0.031)are the two independent risk factors for long-term atrioventricular conduction block post TAVR.Conclusions:The ratio of complete cardiac conduction recovery post TAVR is 50.0%.Older age(≥75 year)and new-onset severe heart conduction block are independent risk factors for long-term atrioventricular conduction block post TAVR procedure.

Objective:This study aims to investigate the feasibility and safety of implanting leadless pacemakers in the low septum and its impact on cardiac electrical synchronization.Methods:A total of 36 patients who received leadless pacemaker implantation at Fuwai Central China Cardiovascular Hospital from January 2021 to August 2023 were included in this study.According to implantation sites of leadless pacemakers,patients were divided into mid-septal group(n=16)and low-septal group(n=20).The clinical characteristics and cardiac electrical synchronization were compared between the two groups.Results:There were 21 male patients,mean age was(68±13)years old.There was no statistical difference in the type of brady-arrhythmia between the two groups(P=0.73).There were 61 implant attempts in these 36 patients,and there was no significant difference in the number of attempts,procedure time,and pacemaker parameters between the two groups,but the average procedure time tended to be shorter in the low-septal group([84±37]minutes vs.[105±35]minutes,P=0.09).In terms of electrical synchronization,there was no statistical difference in QRS duration between the low-septal group and the mid-septal group([162.0±21.1]ms vs.[174.0±14.8]ms,P=0.20).There were no vascular puncture complications,cardiac perforation,or pericardial tamponade during the procedure.There were no complications and readmissions related to the leadless pacemaker during follow-up period.Conclusions:Our results show that the implantation of a leadless pacemaker in the low ventricular septum is safe and effective,has a similar impact on cardiac electrical synchronization as mid-septal pacing.

Objectives:This study aims to explore the impact of new-onset heart conduction block post transcatheter aortic valve replacement(TAVR)on the cardiac conduction status during 1-year follow-up.Methods:A total of 130 patients who completed TAVR surgery at Fuwai Central-China Cardiovascular Hospital from July 2019 to October 2022 were screened.Among them,56 cases with postoperative heart conduction block were selected for analysis.According to the degree of heart block,patients were divided into mild block group(n=36),moderate block group(n=9),and severe block group(n=11).The clinical characteristics and cardiac conduction conditions at 1-year follow-up between different groups were compared.Results:During a mean(8.5±4.1)months follow-up period,10(17.9%)patients had long-term atrioventricular conduction block,and 46(82.1%)patients had partial or complete recovery of heart block,with 28(50.0%)patients with completely recovered cardiac conduction.In the mild block group,22(61.1%)cases were completely recovered,9(25.0%)patients partly recovered,and 5(13.9%)cases uncovered.In the moderate block group,2(22.2%)cases were completely recovered,5(55.6%)patients partly recovered,and 2(22.2%)cases uncovered.Difference in long-term atrioventricular conduction block among three groups was statistically significant(P<0.001).The Kaplan-Meier curve shows that patients with moderate to severe heart block have a higher rate of long-term atrioventricular conduction block(86.1%vs.77.8%vs.72.7%,log-rank P=0.03).Cox multivariate analysis exhibited that old age(≥75 years old,HR=1.204,95%CI:1.051-1.525,P=0.041)and severe heart conduction block(HR=1.106,95%CI:1.100-1.616,P=0.031)are the two independent risk factors for long-term atrioventricular conduction block post TAVR.Conclusions:The ratio of complete cardiac conduction recovery post TAVR is 50.0%.Older age(≥75 year)and new-onset severe heart conduction block are independent risk factors for long-term atrioventricular conduction block post TAVR procedure.

OBJECTIVE: To analyze and discuss the feasibility of rabbit carotid artery treated with decellularization and photo-oxidation. METHODS: Sixty vascular slices of rabbit carotid artery were divided into a fresh group, a cryopreservation group, a glutaraldehyde group, and a decellularization plus photo-oxidation group 15 in each group. To evaluate the physical properties of all the rabbit carotid arteries by testing heat-shrinking temperature, tensile stress and the max elongation of each group. Then by buliding subcutaneous embedding model in SD rats we evaluated the biological stability and the anti-calcification function property of the above rabbit carotid arteries, and the detection means included HE stain, atomic absorption spectrometry and Von-Kossa calcium salt stain. RESULTS: The heat-shrinking temperature, tensile stress and the max elongation in the cryopreservation group were lower or shorter than those of the other groups and the difference had statistical significance (P<0.05). Although the heat-shrinking temperature and the tensile stress in the decellularization plus photo-oxidation group were lower or shorter than those in the glutaraldehyde group (P<0.05), the max elongation in the decellularization plus photo-oxidation group was much longer than that in the glutaraldehyde group (P<0.05). The rabbit carotid artery treated with decellularization plus photo-oxidation showed lower immunogenicity and better biological stability and better anti-calcification property compared with the other groups. CONCLUSION Decellularization associated with photo-oxidation is a suitable and novel protocol for small caliber artery allograft with a diameter of less than 6 mm which is unbreakable to mechanical properties and conducive to biological stability, which has a broad prospect.
Animals ; Blood Vessel Prosthesis ; Calcinosis ; prevention & control ; Carotid Arteries ; cytology ; transplantation ; Cell Separation ; methods ; Female ; Histocytological Preparation Techniques ; Male ; Oxidants, Photochemical ; pharmacology ; Oxidation-Reduction ; Rabbits ; Rats ; Rats, Sprague-Dawley ; Transplantation, Heterologous

Objective To observe the intluence ot chemokine RANTES influence on cardiac allograft acute rejection caused by alloreactive memory CD4+ T cells (Tm) adoptive transfer.Methods Heterotopic heart transplantation (HTx) from Balb/c donors to C57BL/6 recipients was performed by anastomosis of the vessels of the neck.Mice undergoing heterotopic heart transplantation received either adoptive transfer of 1 × 106 CD4+ Tm from the spleen of alloantigen-primed C57BL/6 mice or no cells (control group).After the cardiac transplantation,the mean survival time (MST),mean histologic rank of rejection,relative gene expression and serum concentration of RANTES in the cardiac grafts.Results (1) The percentage of CD4+ Tm was 26.83％ at the spleen of alloantigenprimed mice; (2) The MST was 5.17 ± 0.17 days in the CD4+ Tm+ HTx group versus 7.76 ± 0.21 days at the HTx group (control group) (P＜0.01); (3) The histological tests revealed that mean histologic rank of rejection activity in the sections of cardiac allografts on the day 5 post grafting was grade 3.92 ± 0.08 in the HTx+ CD4+Tm group versus grade 2.67 ± 0.14 in HTx group (P＜0.01) ;(4) The relative gene expression level of RANTES was 2.6 ± 0.21 in the CD4+ Tm + HTx group,significantly higher than in the control group (P＜0.01) ; (5) The serum concentration of RANTES in the CD4+ Tm+ HTx group was 223.6 ± 16.79 pg/mL,higher than in the control group (120.7 ±9.47 pg/mL,P＜0.01).Conclusion Alloreactive CD4+ Tm contribute to the increased expression and secretion of RANTES,and cardiac allograft acute rejection was more extensive in the CD4 + Tm + HTx group.