[The timing of pericardial drainage catheter removal and restart of the anticoagulation in patients suffered from perioperative pericardial tamponade during atrial fibrillation catheter ablation and uninterrupted dabigatran: Experiences from 20 cases].

Objective: To investigate the timing of pericardial drainage catheter removal and restart of the anticoagulation in patients with atrial fibrillation (AF) suffered from perioperative pericardial tamponade during atrial fibrillation catheter ablation and uninterrupted dabigatran. Methods: A total of 20 patients with pericardial tamponade, who underwent AF catheter ablation with uninterrupted dabigatran in Beijing Anzhen Hospital from January 2019 to August 2021, were included in this retrospective analysis. The clinical characteristics of enrolled patients, information of catheter ablation procedures, pericardial tamponade management, perioperative complications, the timing of pericardial drainage catheter removal and restart of anticoagulation were analyzed. Results: All patients underwent pericardiocentesis and pericardial effusion drainage was successful in all patients. The average drainage volume was (427.8±527.4) ml. Seven cases were treated with idarucizumab, of which 1 patient received surgical repair. The average timing of pericardial drainage catheter removal and restart of anticoagulation in 19 patients without surgical repair was (1.4±0.7) and (0.8±0.4) days, respectively. No new bleeding, embolism and death were reported during hospitalization and within 30 days following hospital discharge. Time of removal of pericardial drainage catheter, restart of anticoagulation and hospital stay were similar between patients treated with idarucizumab or not. Conclusion: It is safe and reasonable to remove pericardial drainage catheter and restart anticoagulation as soon as possible during catheter ablation of atrial fibrillation with uninterrupted dabigatran independent of the idarucizumab use or not in case of confirmed hemostasis.

[Safety and effectiveness of left atrial appendage occlusion in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis].

Objective: To evaluate the safety and effectiveness of left atrial appendage occlusion (LAAO) in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis. Methods: Six patients with AF and end-stage renal disease(ESRD)on long term hemodialysis who underwent LAAO from March 2017 to March 2021 in Beijing Anzhen Hospital were enrolled. Baseline characteristics such as age, sex, types of arrhythmia, stroke and bleeding score, and continuous dialysis time were collected. Four patients underwent LAAO, two patients underwent the combined procedure of catheter ablation and LAAO. Perioperative treatment and serious complications were recorded. Transesophageal echocardiography was repeated at 45 days and 60 days after the procedure. Telephone follow-up was conducted at 3, 6 and 12 months after the procedure, and every 6 months thereafter. Thromboembolism and major bleeding events and survival were evaluated. Results: The average age was (66.7±17.0) years old, and 5 were male (5/6). There were 4 patients with paroxysmal AF (4/6), and 2 patients with persistent AF (2/6). The mean CHA2DS2-VASc score was (4.8±1.5), and the HAS-BLED score was (3.5±1.4). The duration of hemodialysis was 2.6 (1.1, 8.3) years. Successfully Watchman implantation was achieved in all patients. There were no severe perioperative complications, and no device related thrombosis or leaks were observed by transesophageal echocardiography. During a mean of 22.0 (12.0, 32.0) months follow-up, there was no thromboembolism or major bleeding events. A total of 2 patients died, one from sudden cardiac death, and another one from heart failure. Conclusions: LAAO may be a safe and effective therapeutic option for prevention of thromboembolism in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis, further studies with larger patient cohort are needed to confirm our results.

[Clinical analysis of left atrial appendage occlusion for stroke prevention in elderly patients with atrial fibrillation].

To evaluate the efficacy and safety of left atrial appendage occlusion (LAAO) in patients with atrial fibrillation (AF) over 75 years. A total of 82 patients with AF who underwent LAAO successfully in Beijing Anzhen Hospital from March 2014 to March 2019 were divided into two groups according to age: the elderly group (aged>75 years) and the young group (aged ≤75 years). Risk of perioperative complications and incidence of ischemic stroke and major bleeding during follow-up were retrospectively analyzed. The results showed that there were no significant differences in procedure-related ischemic stroke(0 vs.1.6%,P=0.768) and major bleeding (0 vs.1.6%,P=0.768) during perioperative period between the two groups. No complications as death or pericardial tamponade occurred in the two group. During a (25.9±15.9) months period of followed up, ischemic stroke event rate was 3.6/100 person-years in the elderly group and 4.9/100 person-years in the young group, respectively. Major bleeding event rate was 2.5/100 person-years in the elderly group and 0/100 person-years in the young group, respectively. Compared with the expected ones, the relative risk reduction (RRR) of stroke in the elderly group was more profound than that in the young group (32.0% vs. 25.0%), while the risk of major bleeding in the young group was significantly lower than that in the elderly group (RRR 100% vs. 56.9%). Therefore, LAAO might be suitable for stroke prevention in the elderly AF patients.

[Effectiveness and safety of idarucizumab in the management of perioperative complications of atrial fibrillation catheter ablation in atrial fibrillation patients under dabigatran therapy].

Objective: To investigate the efficacy and safety of idarucizumab in the treatment of perioperative cardiac tamponade and thromboembolic events during catheter ablation in atrial fibrillation (AF) patients under dabigatran therapy. Methods: This study was a retrospective analysis enrolling patients under dabigatran therapy, who underwent catheter ablation for AF at Beijing Anzhen Hospital from January 2019 to December 2020 and developed perioperative cardiac tamponade or acute ischemic stroke (AIS) and received idarucizumab to reverse the anticoagulant effect of dabigatran. Patients' age, sex, renal function, coagulation test and safety events at 30 d after idarucizumab administration were collected and analyzed. The clinical presentation and prognosis were also analyzed. Results: A total of 7 patients were included, 2 (2/7) were male, mean age was (66.3±11.2) years, serum creatinine level was (66.3±13.6) µmol/L, estimated glomerular filtration rate was (89.4±11.2) ml·min-1·1.73 m-2, CHA2DS2-VASc and HAS-BLED scores were (3.2±1.9) and (1.3±1.3), respectively. Five patients (5/7) developed cardiac tamponade during the perioperative period and the time interval to the last dose of dabigatran was (6.3±2.6) h. Idarucizumab was given at (36.4±16.7) min after the definitive diagnosis of cardiac tamponade. A significant decrease of activated partial thromboplastin time was achieved after idarucizumab administration in all five cases. Pericardial puncture and drainage were applied to all patients (5/5) with cardiac tamponade, the drainage volume was (1 037.0±846.9) ml, the retention time of pericardial drainage catheter was (27.9±13.9) h, and the recovery time of anticoagulation was (28.4±13.2) h. One patient (1/5) underwent thoracotomy for hemostasis due to excessive blood loss with the aim of ensuring complete hemostasis. Bleeding occurred in 1 patient (1/5) after the first restart of anticoagulation. AIS occurred in 2 patients (2/7) after operation. One case (1/2) received intravenous thrombolysis after receiving 5.0 g idarucizumab, no hemorrhagic transformation was observed, and the recovery process was satisfactory. Another patient in this group experienced significantly prolonged onset time and 5.0 g idarucizumab was applied before intravascular thrombectomy, there was no bleeding complication in this patient after thrombectomy. At the time of discharge, the consciousness was not significantly improved, and the muscle strength of the right lower limb was recovered somehow compared with that before operation. No hypersensitivity reactions or thrombotic events occurred in these patients within 30 days of the administration of idarucizumab. Conclusion: In AF catheter ablation-associated cardiac tamponade and AIS, idarucizumab is safe and effective in rapidly reversing the anticoagulant effect of dabigatran, use of thrombectomy saves valuable time for timely hemostasis and improvement of cerebral blood circulation.

[Clinical observation on six children of left bundle branch area pacing].

Objective: To explore the safety and effectiveness of left bundle branch area pacing (LBBAP) in children. Methods: Clinical data, pacing electrocardiogram and parameters of 6 patients (5 females and 1 male) who underwent permanent pacemaker implantation and LBBAP from January to June 2019 in the Department of Pediatric Cardiology of Anzhen Hospital were retrospectively analyzed. Results: The weight of the 6 patients aged between 9 and 14 years ranged from 26 to 48 kg. Five patients were diagnosed with third degree atrioventricular block, and 1 patient was diagnosed with cardiac dysfunction after right ventricular apical pacing. Cardiac function decreased in one patient and remained normal in the other five patients. Left ventricular end diastolic diameter (LVEDD) Z score was 1.85±0.65. V(1) lead showed changes like right bundle branch block in pacing electrocardiogram. No significant difference was found regarding QRS wave duration ((95±13) ms vs. (111±20) ms, t=-1.610, P>0.05) between preoperation and postoperation. Pacing threshold was (0.85±0.26) V. The sensing threshold was (15.0±4.3) mV and the impedance was (717±72) Ω. P potential was recorded in 3 cases. The earliest left ventricular local activation time was (56±5) ms and remained stable at different output voltages. Postoperative echocardiography revealed that the electrodes were located near the endocardium of the left ventricular septum. No complications such as myocardial perforation and electrode dislocation occurred during follow-up. The pacing threshold, sensing threshold and impedance were (0.60±0.09)V, (16.1±3.9)mV, (662±78)Ω respectively at 3 months after operation. The patient with low left ventricular ejection fraction (LVEF) recovered to normal on the 3 rd day after LBBAP (45% vs. 57%). The LVEDD Z score decreased to (1.1±0.3) at 3 months after operation and was significantly lower than that before operation (t=2.38, P<0.05). Conclusions: LBBAP in children can achieve narrow QRS pacing andphysiological pacing with stablepacing parameters. It can improve left ventricular enlargement caused by long-term bradycardia, and cardiac dysfunction and cardiac enlargement caused by long-term right ventricular apical pacing quickly and effectively.LBBAP is safe and feasible for older children in the near future. However, the long term potential risks of LBBAP need further observation and study.

[Cloning of a full length cDNA of human thrombopoietin receptor c-Mpl and construction of engineered cells that stably express c-mpl].

A full length cDNA fragment encoding for human thrombopoietin receptor c-Mpl has been amplified by RT-PCR from the total RNA of human HEL cells. The complete sequence of the cloned cDNA was determined and is identical to that previously reported. Then the fragment was subcloned into the mammalian expression vector pcDNA3 and the resulting plasmid is designated as pcMPL. K562 cells, which do not express c-mpl, were transfected with pcMPL and pcDNA3, respectively. The transformants were selected with G418 and then tested by Northern and Southern blotting. A group of engineered cell lines stably expressing c-mpl have been obtained, which will facilitate further research on the signaling mediated by c-Mpl.

Nucleotide sequence of a cloned human HBV mutant (pDKHBV) in duck hepatoma of Qidong County.

This is the first report to describe the presence of an HBV-like DNA sequence in two hepatoma and their tumor surrounding liver tissues, one precancerous and one non-malignant liver tissue of ducks collected from Qidong County of China. The HBV-like sequences were either in an episomal form of 3.2 kb or in an integrated form of various sizes, while the DHBV DNA sequences (3.0 kb) were either present or absent in these tissues and in different size pattern. Furthermore, there was no evidence of cross-hybridization between HBV-like DNA sequences in duck and DHBV DNA. A 3.2 kb HBV-like DNA sequence has been cloned from one duck hepatoma (40 K), designated as pDKHBV. The 3218 bp full-length nucleotide sequence of this clone has been determined, which had no apparent homology with Duck Hepatitis B Virus (DHBV) genome, but was highly homologous to human HBV adw2 subtype (99.0%). The sequence was composed of four open reading frames for HBV gene Pre-S/S, X, C and P respectively. In addition to multiple sites of point mutation, one nt and two nt deletion were detected downstream the initiation codon of Pre-S1 gene and at the 3' end of C gene respectively, thereby suggesting a frameshift mutation in Pre-S gene and C gene. Based on these results, it was implicated that an unusual HBV variant might exist in Qidong County, which might have transmitted into duck through some yet unknown mechanisms. The possibility from exogenous contamination could be thus excluded.

Transthyretin (prealbumin) gene in human primary hepatic cancer.

From a subtracting cDNA library constructed from normal liver versus human primary hepatic cancer (PHC) a cDNA clone pG8 was isolated. Using it as a probe, RNA extracted from one human liver and 9 PHC samples were analyzed by Northern hybridization. As expected, its mRNA was highly expressed in liver; however, the expression was strikingly suppressed in PHC. Only weak signal was observed in 2 out of 9 PHC, while no signal was detectable in the other 7 samples. Utilizing pG8 as a probe, DNA from the same PHC specimens was analyzed after MspI digestion and Southern hybridization. Deletion of DNA fragment was observed in 4 out of 9 samples. In further study of cancer and non-cancerous liver from other 7 PHC patients, similar deletion of DNA fragments in cancer was observed in 4 out of 7 samples. After sequencing of the clone of 572 bp, it was unexpectedly found that pG8 was completely homologous to the coding sequence of transthyretin, TTR gene, as TTR (or prealbumin) gene has been known to be linked to a hereditary disorder, familial amyloidosis (FAP), and related to thyroxine transport and binding to retinol-RBP (the retinol binding protein) complex. This is the first report of a study on TTR in human primary hepatic cancer. Since TTR gene was strikingly suppressed in mRNA expression and possibly defective in its gene structure, it was strongly implicated that TTR might be an important gene marker or a candidate of anti-oncogene for human PHC. The biological activity of TTR gene is under study.