Study of the optimum fluoroscopic angle for the implant fixation test of a leadless cardiac pacemaker.

The Micra TPS™ (Medtronic) is the first leadless pacemaker listed in China. The best fluoroscopic angle for the intraoperative fixation test is selected according to different implantation sites to reduce the fluoroscopy duration and radiation dose, and the test is based on the early safety and effectiveness of the device after implantation. A total of 110 patients who underwent Micra TPS™ implantation were selected. Eighty patients were in group A, and 30 patients were in group B. Under the guidance of the conclusions from group A, the fluoroscopy duration, radiation dose and number of fluoroscopic positions of the best fluoroscopic angle of the fixation test according to different positions of the implanted interventricular septum were compared. In 85.0% of the group A implants, these angles were based on the right interior oblique (RAO) angle, with 48.5% cranial (CRA) and 29.4% caudal (CAU) angles. The angle of the tilting head side of the RAO angle was prioritized in group B, and referring to the average angle data, the average fluoroscopy duration for finding the best angle of fixation test was 1.7 ± 0.6 vs. 3.2 ± 1.8 min (P < 0.001), the average radiation dose was 270.4 ± 56.3 vs. 338.1 ± 112.9 mGy (P = 0.002), and the average number of fluoroscopic positions was 2.2 ± 0.6 vs. 4.2 ± 2.1 (P < 0.001), which was significantly less than that in group A. This study found that there was regularity in the fluoroscopic angle for the fixation test during Micra TPS™ operation.Level of Evidence Level 3, local nonrandom sample.

[The effects of different herbal compound and extracts from different extraction methods on hypoxia tolerance in mice].

Objective: To investigate the effects of different prescription compositions of traditional Chinese medicine and its different extraction methods of compound formula extracts on hypoxia tolerance in mice, in order to preferably select their prescription compositions and preparation extraction methods. Methods: Male BALB/c mice were randomly divided into 6 groups: blank control group, compound danshen group, compound Rhodiola Rosea alcohol-water extract group (Rhodiola rosea, Astragali Radix, Polygonati Rhizoma, Lycii Fructus), compound Rhodiola Rosea water extract group, compound Astragalus alcohol-water extract group (Astragali Radix, Polygonati Rhizoma, Lycii Fructus) and compound Astragalus water extract group, 30 mice in each group. Each group was administered continuously by gavage for 10 d. The blank group was gavaged with sterilized injection water. The mice in the other groups were treated with 0.15 g/kg of compound danshen, 3 g/kg of compound Rhodiola Rosea alcohol-water extract or water extract, and 1.7 g/kg of compound Astragalus alcohol-water extract or water extract, respectively. Each group was subjected to normobaric hypoxia tolerance test, sodium nitrite toxicity survival test and acute cerebral ischemia-hypoxia test 1 h after the last gavage, and the mice brain tissues were used to determine the activity of antioxidant enzymes and metabolites related to oxidative stress. Results: Compared with the blank control group, in normobaric hypoxia tolerance test, the survival time of mice in the compound danshen group and the compound Astragalus alcohol-water extract group and water extraction group was prolonged significantly (P＜0.01), and the number of open-mouth gasping after cerebral ischemia and hypoxia was increased significantly (P＜0.05). There was no statistical difference in survival time after sodium nitrite injection in each group. Compared with the blank control group, the activities of T-AOC, SOD, GSH and CAT were increased significantly (P＜0.05, P＜0.01) and the content of MDA was decreased significantly (P＜0.01) in the compound Astragalus water extract group. Compared with the compound danshen group, the activities of SOD, CAT and GSH were increased significantly (P＜0.01, P＜0.05) and the content of MDA was decreased significantly (P＜0.05). Conclusion: Compound Astragalus water extraction has the best effect of hypoxia tolerance, compound Rhodiola Rosea can eliminate Rhodiola rosea and consists of Astragali Radix, Polygonati Rhizoma, Lycii Fructus and its extraction method is water extraction.

Aging-induced atrial fibrosis in If current change and its effect on atrial fibrillation in dogs.

BACKGROUND: Atrial fibrillation (AF) is a very common type of cardiac arrhythmia that threatens public health. Aging is an independent AF risk factor. However, the mechanism of age-related AF remains unclear. METHODS: A total of 36 Beagle dogs were selected and divided into three groups (12 in each group): two groups were 9-year-old aged dogs, and one group was 4-year-old adult dogs. Electrophysiological testing was employed to determine if modeling is successful. Patch-clamp technique was employed to measure the If current. The expression of protein and mRNA related to If current were also tested. Collagen deposition was observed with the use of Masson staining. RESULTS: Aging resulted in a higher collagen deposition percentage in the left atrium. The hyperpolarization-activated cyclic nucleotide-gated (HCN)2 and HCN4 expressions were increased in the atria and pulmonary veins but decreased in the sinus node of the aged group. Moreover, in the aged group, the left atrium mRNA expressions of Kcnd2 (Potassium voltage-gated channel subfamily D member 2), Kcnh2, Kcnq1, Kcnj2, Kcnj11, and CACNA1H were significantly downregulated. The aged AF group also demonstrated sustained AF and significant changes in electrophysiological characteristics. The If current demonstrated an increased amplitude and was easier to activate in the aged AF group than in younger group. Finally, AF occurrence exacerbated aging-induced cardiac fibrosis, thereby aggravating the above-listed symptoms. CONCLUSION: With age, the increase in atrial fibrosis affected the expression of the ion channels, thereby modulating the If current. Moreover, AF also further exacerbated the degree of atrial fibrosis.

Incidence, Risk Factors, and Prognosis of Tricuspid Regurgitation After Cardiac Implantable Electronic Device Implantation: A Systematic Review and Meta-analysis.

This study aimed to determine the pooled incidence, risk factors, and clinical prognosis of tricuspid regurgitation (TR) deterioration after implantation of a cardiac implantable electronic device (CIED). The study was designed as a meta-analysis of randomized controlled trials and observational studies. Patients with indications for CIEDs were selected as participants and CIED implantation was the intervention. PubMed, EMBASE, the Cochrane Library, China National Knowledge Infrastructure, Wanfang Data, and China Science and Technology Journal Database were searched systematically to identify studies. Thirty-seven studies with 8,144 patients were included. The pooled incidence of TR deterioration of at least one grade was 25.1% (95% confidence interval [CI], 20.9-29.3; Z = 11.60; p < 0.01; I2 = 94.8%, p < 0.01). Compared with TR incidence after permanent pacemaker implantation, that after implantable cardioverter-defibrillator implantation did not significantly increase (22.68% v 29.18%; odds ratio [OR], 0.615; 95% CI, 0.271-1.339; Z =1.16; p = 0.246). The pooled incidence of TR deterioration of at least two grades was 9.4% (95% CI, 6.6-12.1; Z = 6.72; p < 0.01; I2 = 86.0%, p < 0.01). Lead interference (OR, 8.704; 95% CI,4.450-17.028; Z= 6.32; p < 0.001) and pacemaker implantation time (OR, 1.153; 95% CI, 1.082-1.229; Z = 4.37; p < 0.001) were risk factors for worsening TR. Baseline atrial fibrillation, age, baseline mild TR, and left ventricular ejection fraction were not associated with TR. All-cause mortality (>one year after pacemaker implantation) was higher in patients with TR deterioration (hazard ratio, 1.598; 95% CI, 1.275-2.002; Z = 4.07; p < 0.01; I2 = 0%). TR is a common complication after CIED implantation. Lead interference and pacemaker implantation time were risk factors for TR worsening. Compared with patients without TR deterioration after pacemaker implantation, patients with TR deterioration had a poorer prognosis.

Complete mitochondrial genome of Brachionus rubens from wuhu, China (Rotifera, Brachionidae).

The complete mitochondrial genome of Brachionus rubens was sequenced using primers design, clone culture, DNA extraction, LONG-PCR amplification, purification and clone sequencing. We found that it is composed of two circular chromosomes, designated mtDNA I (11,398 bp) and mtDNA II (12,820 bp). The gene content of the B. rubens mitochondrial genome was similar to that of the previously reported mitochondrial genome of B. plicatilis. It contained 22 tRNA genes, 2 rRNA genes and 12 protein-coding genes (PCGs). Four of the 12 PCGs had an incomplete stop codons, TA（cob, atp6, nd3）or T(cox3). The A + T content of B. rubens mitochondrial genome was apparently higher (mtDNA-I 70.2% and mtDNA II 70.4%) than that of the mitochondrial genome of B. plicatilis (mtDNA-I 63.9% and mtDNA-II 62.9%).

Enhanced atrial internal-external neural remodeling facilitates atrial fibrillation in the chronic obstructive sleep apnea model.

OBJECTIVE: Autonomic imbalance plays a crucial role in obstructive sleep apnea (OSA) associated atrial fibrillation (AF). Here, we investigated the potential neural mechanism of AF induced by OSA. METHODS: Ten dogs were divided into control group (n = 5) and OSA group (n = 5). The chronic OSA model was established by repeat apnea-ventilation cycles for 4 hours a day for 12 weeks. During the process of model establishment, arterial blood gases, atrial effective refractory period (AERP), AF inducibility, normalized low-frequency power (LFnu), normalized high-frequency power (HFnu), and LFnu/ HFnu were evaluated at baseline, 4th week, 8th week, and 12th week. Nerve activities of left stellate ganglion (LSG) and left vagal nerve(LVN) were recorded. Tyrosine hydroxylase(TH), choline acetyltransferase(CHAT), PGP9.5, nerve growth factor(NGF), and c-Fos were detected in the left atrium, LSG, and LVN by immunohistochemistry and western blot. Moreover, high-frequency stimulations of LSG and LVN were conducted to observe the AF inducibility. RESULTS: Compared with the control group, the OSA group showed significantly enhanced neural activity of the LSG, increased AF inducibility, and shortened AERP. LFnu and LFnu/HFnu were markedly increased in the OSA group, while no significant difference in HFnu was observed. TH-positive and PGP9.5-positive nerve densities were significantly increased in the LSG and left atrium. Additionally, the protein levels of NGF, c-Fos, and PGP9.5 were upregulated both in the LSG and left atrium. AF inducibility was markedly increased under LSG stimulation without a stimulus threshold change in the OSA group. CONCLUSIONS: OSA significantly enhanced LSG and left atrial neural remodeling, and hyperactivity of LSG may accelerate left atrial neural remodeling to increase AF inducibility.

KCNQ1 G219E and TRPM4 T160M polymorphisms are involved in the pathogenesis of long QT syndrome: A case report.

RATIONALE: Long QT syndrome (LQTS) is an inheritable disease characterized by prolonged QT interval on the electrocardiogram. The pathogenesis of LQTS is related to mutations in LQTS-susceptible genes encoding cardiac ion channel proteins or subunits. PATIENT CONCERNS: Here, we reported a 37-year-old female Uygur patient with palpitation and loss of consciousness. DIAGNOSES: At the time of admission, a 12-lead electrocardiogram showed a QTc interval of 514 ms. Genetic analysis revealed KCNQ1 G219E and TRPM4 T160M mutations. INTERVENTIONS: Although beta-blockers remain the mainstay in treating LQTS, the patient underwent implantation of an automatic cardioverter defibrillator due to life-threatening arrhythmias. OUTCOMES: To explore the effect of the calcium ion antagonist verapamil on ion channels, we generated human induced pluripotent stem cell cardiomyocytes (hiPSC-CMs) from the peripheral blood mononuclear cells of the patient. The changes of action potential duration in response to verapamil were observed. LESSONS: Our results showed that patient-derived hiPSC-CMs could recapitulate the electrophysiological features of LQTS and display pharmaceutical responses to verapamil.

A prospective comparison of four methods for preventing pacemaker pocket infections.

This study aims to evaluate four pacemaker pocket cleaning methods for preventing implantation-related infections. This single-center trial prospectively randomized 910 patients undergoing first-time pacemaker implantation or replacement into four pocket cleaning methods: hemocoagulase (group A, n = 228), gentamicin (group B, n = 228), hemocoagulase plus gentamicin (group C, n = 227), and normal saline (group D, n = 227). Before implanting the pacemaker battery, the pockets were cleaned with gauze presoaked in the respective cleaning solutions. Then, these patients were followed up to monitor the occurrence of infections for 1 month after implantation. Twelve implantation-related infections occurred in 910 patients (1.32%): four patients from group A (1.75%), three patients from group B (1.32%), two patients from group C (0.88%), and three patients from group D (1.32%) (P > .05). Furthermore, two patients developed bloodstream infections (0.22%), and both of these patients were associated with pocket infection (one patient was from group A, while the other patient was from group C, respectively). No cases of infective endocarditis occurred. The differences in the number of infections in these study groups were not statistically significant. The application of hemocoagulase, gentamicin, hemocoagulase plus gentamicin, or normal saline on the presoaked gauze before implantation was equally effective in preventing pocket-associated infections.

LDL-C/HDL-C is associated with ischaemic stroke in patients with non-valvular atrial fibrillation: a case-control study.

BACKGROUND: This study explored the relationships between the low-/high-density lipoprotein cholesterol ratio (LDL-C/HDL-C) and other clinical indicators and ischaemic stroke (IS) in patients with non-valvular atrial fibrillation (NVAF) in Xinjiang. The findings could provide a theoretical and therapeutic basis for NVAF patients. METHODS: NVAF patients who were admitted to 10 medical centres across Xinjiang were divided into stroke (798 patients) and control (2671 patients) groups according to the occurrence of first acute IS. Univariate and multivariate logistic regression analysis were used to examine the independent risk factors for IS in NVAF patients. Factor analysis and principal component regression analysis were used to analyse the main factors influencing IS. Receiver operating characteristic (ROC) curve analysis was used to evaluate the discriminatory ability of LDL-C/HDL-C for predicting the occurrence of IS. RESULTS: The stroke group had an average age of 71.64 ± 9.96 years and included 305 females (38.22%). The control group had a mean age of 67.30 ± 12.01 years and included 825 females (30.89%). Multivariate logistic regression showed that the risk of IS in the highest LDL-C/HDL-C quartile (≥2.73) was 16.23-fold that of the lowest quartile (< 1.22); IS risk was 2.27-fold higher in obese patients than in normal-weight subjects; IS risk was 3.15-fold higher in smoking patients than in non-smoking patients. The area under the ROC curve of LDL-C/HDL-C was 0.76, the optimal critical value was 2.33, the sensitivity was 63.53%, and the specificity was 76.34%. Principal component regression analysis showed that LDL-C/HDL-C, age, smoking, drinking, LDL-C and hypertension were risk factors for IS in NVAF patients. CONCLUSIONS: LDL-C/HDL-C > 1.22, smoking, BMI ≥24 kg/m2 and CHA2DS2-VASc score were independent risk factors for IS in NVAF patients; LDL-C/HDL-C was the main risk factor.

Renal Denervation Reduced Ventricular Arrhythmia After Myocardial Infarction by Inhibiting Sympathetic Activity and Remodeling.

Background Ventricular arrhythmia after myocardial infarction is the most important risk factor for sudden cardiac death, which poses a serious threat to human health. As the correlation between autonomic nervous systemic dysfunction and heart rhythm abnormality has been gradually revealed, remedies targeting autonomic nervous system dysfunction, especially the sympathetic nerve, have emerged. Among them, renal denervation is noted for its powerful effect on the inhibition of sympathetic nerve activity. We aim to investigate whether renal denervation can reduce ventricular arrhythmia after myocardial infarction and thus decrease the risk of sudden cardiac death. In addition, we explore the potential mechanism with respect to nerve activity and remodeling. Methods and Results Twenty-four beagles were randomized into the control (n=4), renal denervation (n=10), and sham (n=10) groups. Permanent left anterior descending artery ligation was performed to establish myocardial infarction in the latter 2 groups. Animals in the renal denervation group underwent both surgical and chemical renal denervation. Compared with dogs in the sham group, dogs in the renal denervation group demonstrated attenuated effective refractory period shortening and inhomogeneity, flattened restitution curve, increased ventricular threshold, and decreased ventricular arrhythmia. Heart rate variability assessment, catecholamine measurement, and nerve discharge recordings all indicated that renal denervation could reduce whole-body and local tissue sympathetic tone. Tissue analysis revealed a significant decrease in neural remodeling in both the heart and stellate ganglion. Conclusions Surgical and chemical renal denervation decreased whole-body and local tissue sympathetic activity and reversed neural remodeling in the heart and stellate ganglion. Consequently, renal denervation led to beneficial remodeling of the electrophysiological characteristics in the infarction border zone, translating to a decrease in ventricular arrhythmia after myocardial infarction.

Increase of Autonomic Nerve Factors in Epicardial Ganglionated Plexi During Rapid Atrial Pacing Induced Acute Atrial Fibrillation.

BACKGROUND The cardiac autonomic nervous system plays an essential role in epicardial ganglionated plexi (GP) regulation of atrial fibrillation onset and progression. To date, the activity of GP and the function of the cardiac autonomic nervous system are not well understood. The aim of this study was to determine alterations in epicardial GP cholinergic nerve, adrenergic nerve, and nerve growth factor expression using rapid atrial pacing to induce atrial fibrillation in canines. MATERIAL AND METHODS Nine healthy adult beagles were divided into two groups: the pacing experimental group (n=6) and the sham-operation control group (n=3). For the pacing group, high frequency pacing of the left atrial appendage was performed for eight hours. In the control group, electrodes were implanted without rapid atrial pacing. Immunocytochemistry was used to identify neurons positively expressing tyrosine hydroxylase, choline acetyl transferase, nerve growth factor and neurturin. RESULTS After successfully establishing a rapid atrial pacing of the left atrial appendage induced atrial fibrillation model, we found that expression of choline acetyl transferase, tyrosine hydroxylase, nerve growth factor, and neurturin was significantly higher in the rapid atrial pacing group than the control group (p<0.05). CONCLUSIONS In our model, incremental excitability of both the adrenergic and cholinergic nerves led to frequent incidents of atrial fibrillation, which were possibly due to an imbalance of autonomic nerve factors in the epicardial GP during acute atrial fibrillation.

The complete mitochondrial genome of the Zacco platypus, Huangshan, China (Cypriniformes: Cyprinidae, subfamily Daninninae).

The mitochondrial genome of Zacco platypus (Cypriniformes: Cyprinidae, subfamily Daninninae) is a circular molecule of 16,611 bp in length, containing 37 typical animal mitochondrial genes: 13 protein-coding genes (PCGs), 2 ribosomal RNAs, 22 transfer RNAs and a D-loop region. Its gene order and arrangement are identical to the common type found in most fish mitogenomes. All PCGs start with a typical ATG codon except for COI which use GTG as start codon; all PCGs terminate in the common stop codon TAA or TAG, except for the COII which use single T as stop codon. The D-loop region is 928 bp long, located between tRNAPro and tRNAPhe genes. It contains some structures of repeated motifs and microsatellite-like elements characteristic of the Cyprinidae.

The complete mitochondrial genome of the Acrossocheilus fasciatus (Cyprinidae, Barbinae).

The mitochondrial genome of Acrossocheilus fasciatus (Cyprinidae, Barbinae) is a circular molecule of 16,589 bp in length, containing 37 typical animal mitochondrial genes: 13 protein-coding genes (PCGs), 2 r RNAs, 22 t RNAs and a non-coding D-loop region. Its gene order and arrangement are identical to the common type found in most fish mitogenomes. All PCGs start with a typical ATG codon except for COI which use GTG as a start codon; all PCGs terminate in the common stop codon TAA or TAG, except for the ND2, ND3, ND4, COII, Cytb and COIII which use single T or TA as a stop codon. The non-coding D-loop region is 938 bp long, located between tRNAPro and tRNAPhe genes. It contains some structures of repeated motifs and microsatellite-like elements characteristic of the Cyprinidae.

[Construction and tobacco transformation of COR and BBE genes hairpin RNA vector of Papaver somniferum].

The gene expressions of codeinone reductase (COR) and berberine bridge enzyme (BBE) in Papaver somniferum were blocked by RNA hairpin of RNA interference (RNAi). The complete sequences of COR and BBE genes were cloned by reverse transcription-polymerase chain reaction (RT-PCR), the results of homology comparison revealed that the cloned COR and BBE genes had high homology with the other gene family members reported in the GenBank. The target sequences of COR and BBE genes were screened in accordance with the design principle of RNAi, a 643 bp fusion gene was obtained by the method of overlapping PCR, then plant expression vector ihpRNA was constructed based on intermediate vector pHANNIBAL and plant expression vector pCEPSPS. With that 78 transgenic plants were obtained through Agrobacterium-mediated and 17 positive plants were screened by PCR, that could initially indicate that the target fragments of COR and BBE gene had been integrated into tobacco genome.

catena-Poly[[[[2-(2-pyridyl-κN)-1H-benzimidazole-κN]copper(II)]-µ-l-methio-ninato-κN,O:O'] perchlorate].

The structure of the title compound, {[Cu(C(5)H(10)NO(2)S)(C(12)H(9)N(3))]ClO(4)}(n), has ortho-rhom-bic symmetry. The chain structure is constructed from square-pyramidally coordinated Cu(II) atoms linked through l-methio-nate ligands. The chains propagate along the a-axis direction and are linked to perchlorate anions via N-H⋯O hydrogen bonds.