Mechanism of Lingbao Huxin Dan in the treatment of bradyarrhythmia complicated with coronary heart disease: a network pharmacology analysis.

OBJECTIVE: To investigate the mechanism of action of the Lingbao Huxin Dan in treating bradycardia arrhythmia with coronary heart disease (BA-CHD) by network pharmacology. METHODS: The active ingredients of the Lingbao Huxin Dan were screened on the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and Bioinformatics tools designed for the analysis of molecular mechanisms of Chinese medicine platform; target prediction was conducted with the SwissTargetPrediction database, and Cytoscape 3.8 was used to construct a drug ingredient-target network. The Genecards, Online Mendelian Inheritance in Man, and DrugBank databases were searched for disease targets. Venn plots were used to display the common targets of BA-CHD and active ingredients. The STRING platform was used to construct a protein-protein interaction network. The Metascape data platform was used for Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to construct a signaling pathway network of the active ingredients of the Lingbao Huxin Dan. RESULTS: There were 121 active ingredients, 899 related targets, 39 targets important in BA-CHD and 14 targets which intersected between the active ingredients and BA-CHD. There were 27 core therapeutic ingredients, 153 biological processes, 18 cell ingredients and 20 molecular functions obtained by GO enrichment analysis. The KEGG pathway analysis yielded 19 signaling pathways. CONCLUSION: RBA-CHD may treat BA-CHD by regulating adrenergic receptor beta-1, alpha 1-α adrenergic receptor, calcium voltage-gated channel subunit alpha1 C, alpha-1ß-adrenergic receptor, nitric oxide synthase 2, beta-2 adrenergic receptor, voltage-dependent calcium channel subunit alpha-2/delta-1, an- giotensin-converting enzyme, Raf-1 proto-oncogene serine/threonine-protein kinase, and other targets, potentially by affecting adrenergic receptor binding and calcium channel opening, to regulate the activity of cardiomyocytes.

High-dose IV magnesium in mesothelioma patients receiving surgery with hyperthermic intraoperative cisplatin: Pilot studies and design of a phase II randomized clinical trial.

INTRODUCTION: Hyperthermic intraoperative cisplatin (HIOC) is associated with acute kidney injury (AKI). Administration of high-dose magnesium attenuates cisplatin-induced AKI (CP-AKI) in animal models but has not been rigorously examined in humans. METHODS: We tested the feasibility and safety of different doses of magnesium in mesothelioma patients receiving HIOC. In Pilot Study 1, we administered a 36-h continuous infusion of magnesium at 0.5 g/h, targeting serum magnesium levels between 3 and 4.8 mg/dL. In Pilot Study 2A, we administered a 6 g bolus followed by an infusion starting at 2 g/h, titrated to achieve levels between 4 and 6 mg/dL. We eliminated the bolus in Pilot Study 2B. RESULTS: In Pilot Study 1, all five patients enrolled completed the study; however, median postoperative Mg levels were only 2.4 mg/dL. In Pilot Study 2A, two of four patients (50%) were withdrawn due to bradycardia during the bolus. In Pilot Study 2B, two patients completed the study whereas two developed postoperative bradycardia attributed to the magnesium. CONCLUSIONS: A 0.5 g/h infusion for 36 h did not achieve therapeutic magnesium levels, while an infusion at 2 g/h was associated with bradycardia. These studies informed the design of a randomized clinical trial testing whether intravenously Mg attenuates HIOC-associated AKI.

Acupuncture Treatment of a Patient with Bradycardia and Idioventricular Rhythm.

A patient with bradycardia and an idioventricular rhythm was observed. According to cardiologists, there is no reliable drug treatment for bradycardia with an idioventricular rhythm; instead, the sole treatment is a pacemaker. In the course of this case, it was shown that acupuncture can restore the heart rhythm from bradycardia to normocardia, and from idioventricular with third-degree atrioventricular node block and an average heart rate of 34 BPM, to normal sinus rhythm with a heart rate of 71 BPM. Additionally, at the end of the treatment, the patient's number of episodes of ventricular extrasystole decreased 36 times (3289 versus 91 episodes). These results show that research on this technique should be continued.

Analysis of prescription medication rules of traditional Chinese medicine for bradyarrhythmia treatment based on data mining.

BACKGROUND: Multiple studies have revealed that Traditional Chinese Medicine (TCM) prescriptions can provide protective effect on the cardiovascular system, increase the heart rate and relieve the symptoms of patients with bradyarrhythmia. In China, the TCM treatment of bradyarrhythmia is very common, which is also an effective complementary therapy. In order to further understand the application of Chinese medicines in bradyarrhythmia, we analyzed the medication rules of TCM prescriptions for bradyarrhythmia by data mining methods based on previous clinical studies. METHODS: We searched studies reporting the clinical effect of TCM on bradyarrhythmia in the PubMed and Chinese databases China National Knowledge Infrastructure database, and estimated publication bias by risk of bias tools ROB 2. Descriptive analysis, hierarchical clustering analysis and association rule analysis based on Apriori algorithm were carried out by Microsoft Excel, SPSS Modeler, SPSS Statistics and Rstidio, respectively. Association rules, co-occurrence and clustering among Chinese medicines were found. RESULTS: A total of 48 studies were included in our study. Among the total 99 kinds of Chinese medicines, 22 high-frequency herbs were included. Four new prescriptions were obtained by hierarchical cluster analysis. 81 association rules were found based on association rule analysis, and a core prescription was intuitively based on the grouping matrix of the top 15 association rules (based on confidence level), of which Guizhi, Zhigancao, Wuweizi, Chuanxiong, Danshen, Danggui, Huangqi, Maidong, Dangshen, Rougui were the most strongly correlated herbs and in the core position. CONCLUSION: In this study, data mining strategy was applied to explore the TCM prescription for the treatment of bradyarrhythmia, and high-frequency herbs and core prescription were found. The core prescription was in line with the treatment ideas of TCM for bradyarrhythmia, which could intervene the disease from different aspects and adjust the patient's Qi, blood, Yin and Yang, so as to achieve the purpose of treatment.

Mechanism of Datura metel on sinus bradycardia based on network pharmacology and molecular docking.

OBJECTIVE: To investigate the mechanism of action of Datura metel in the treatment of sinus bradycardia based on network pharmacology and molecular docking. METHODS: The active ingredients and targets of Datura metel were collected by TCMSP database, and the Cytoscape software was used to map to show the interrelationship. Use 5 databases: GeneCards, PharmGKB, OMIM, DisGeNET, and Drugbank to obtain targets related to sinus bradycardia; establish a protein-to-protein interaction network with the help of the STRING platform; GO and Kyoto Encyclopedia of Genes and Genomes analysis of the selected core targets using the Metascape platform; Finally, the AutoDock platform was used for molecular docking and the results were displayed through Pymol. RESULTS: 27 kinds of active ingredients of the drug were screened, including 10 kinds of main ingredients; 198 drug targets and 1059 disease targets. There are 54 targets of action in the treatment of sinus bradycardia, of which 19 targets such as AKT1, IL6, TNF, and VEGFA are the core targets of Datura metel in the treatment of sinus bradycardia. Kyoto Encyclopedia of Genes and Genomes obtained 18 results suggesting that AGE-RAGE, hepatitis C, relaxin, and JAK-STAT may be key signaling pathways. Molecular docking shows that most components of the drug have good docking ability with the core target, indicating that the prediction results have certain reliability. CONCLUSION: This study preliminarily explores the potential active ingredients and possible mechanisms of action of Datura metel in the treatment of sinus bradycardia and provides a basis for in-depth investigation of its medicinal material basis and mechanism of action.

Persistent Hyperinsulinemia Following High-Dose Insulin Therapy: A Case Report.

INTRODUCTION: Overdoses of beta-adrenergic antagonists and calcium channel antagonists represent an uncommonly encountered but highly morbid clinical presentation. Potential therapies include fluids, calcium salts, vasopressors, intravenous lipid emulsion, methylene blue, and high-dose insulin. Although high-dose insulin is commonly used, the kinetics of insulin under these conditions are unknown. CASE REPORT: We present a case of a 51-year-old male who sustained a life-threatening overdose after ingesting approximately 40 tablets of a mixture of amlodipine 5 mg and metoprolol tartrate 25 mg. Due to severe bradycardia and hypotension, he was started on high-dose insulin (HDI) therapy; this was augmented with epinephrine. Despite the degree of his initial shock state, he ultimately recovered, and HDI was discontinued. Insulin was infused for a total of approximately 37 hours, most of which was dosed at 10 U/kg/hour; following discontinuation, serial serum insulin levels were drawn and remained at supraphysiologic levels for at least 24 hours and well above reference range for multiple days thereafter. CONCLUSION: The kinetics of insulin following discontinuation of high-dose insulin therapy are largely unknown, but supraphysiologic insulin levels persist for some time following therapy; this may allow for simple discontinuation rather than titration of insulin at the end of therapy. Dextrose replacement is frequently needed; although the duration is often difficult to predict, prolonged infusions may not be necessary.

[Efficacy of Shensong Yangxin Capsules in treating bradycardia combined with premature beat: a systematic review and Meta-analysis of randomized clinical trials].

To analyze the efficacy and safety of Shensong Yangxin Capsules in treatment of bradycardia combined with premature beat. Databases, such as CNKI, VIP, WanFang, SinoMed, PubMed, Cochrane Library, ClinicalTrials were retrieved by computers for relevant randomized controlled trials of Shensong Yangxin Capsules in treatment of bradycardia combined with premature beat. Two researchers independently screened out the literatures, extracted data according to the inclusion criteria, and applied the Risk of Bias assessment tool in assessing the methodological quality. The Cochrane systematic evaluation software RevMan 5.3 was used for data analysis. Totally 9 randomized controlled trials including 706 subjects were included. The intervention measure was the single administration with Shensong Yangxin Capsules, and the control measure was the blank control. The results showed that Shensong Yangxin Capsules had an obvious effect on average heart rate(MD=6.59, 95%CI[3.87, 9.31], I~2=90%), premature beat efficacy(RR=1.72, 95%CI[1.53, 1.93], I~2=0%), heart rate efficacy(RR=1.74, 95%CI[1.40, 2.17], I~2=47%), and objective efficacy(RR=1.50, 95%CI[1.31, 1.70], I~2=31%). Eight studies reported safety events, with no significant adverse reaction. In conclusion, the single administration with Shensong Yangxin Capsules may have a certain effect in improving heart rate, controlling premature beats and alleviating clinical symptoms in patients with bradycardia combined with premature beat, with no obvious adverse reaction. Shensong Yangxin Capsules can be used in clinic. This potential conclusion needs to be confirmed in future trials using rigorous methodology.

[Network Meta-analysis of randomized controlled trials of Chinese patent medicine for bradyarrhythmia].

To assess the clinical efficacy of Chinese patent medicine for bradyarrhythmia(BA) by using network Meta-analysis method. Relevant randomized controlled trials(RCTs) of Chinese patent medicine for BA were retrieved from China National Knowledge Infrastructure(CNKI), WanFang Database, VIP database, SinoMed, PubMed and Cochrane Library. The retrieval time ranged from the commencement of each database to February 2019. We completed the literature screening and data extraction according to the pre-determined inclusion and exclusion criteria. The quality of inclusion studies was assessed using the bias risk assessment tool recommended by the Cochrane Handbook of Systematic Review 5.3. The data were analyzed by WinBUGS, and STATA software was used for plotting. Finally, 46 RCTs were included, involving 4 Chinese patent medicines and 3 306 patients. According to the network Meta-analysis, the total effective rate in alleviating BA symptoms had 7 direct comparisons and 3 indirect comparisons. The efficacy of the 4 Chinese patent medicines combined with routine therapy was superior to that of routine therapy, with statistically significant differences. The order of the four Chinese patent medicines by efficacy was as follows: Shenxian Shengmai Oral Liquid>Shensong Yangxin Capsules>Xinbao Pills>Ningxinbao Capsules. The average heart rate had 7 direct comparisons and 3 indirect comparisons. The efficacy of Shenxian Shengmai Oral Liquid and Shensong Yangxin Capsules combined with routine therapy was superior to that of routine therapy, with statistically significant differences. The order of the four Chinese patent medicines by efficacy was as follows: Shenxian Shengmai Oral Liquid>Shensong Yangxin Capsules>Xinbao Pills>Ningxinbao Capsules. The results showed that the Chinese patent medicines combined with routine therapy were effective in the treatment of BA. Due to the differences in the quantity and quality of the included studies on different Chinese patent medicines, the sequencing results of Chinese patent medicines need to be further verified.

Implantation of subcutaneous defibrillator is feasible and safe with monitored anesthesia care.

BACKGROUND: The perioperative anesthesia care during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation is still evolving. OBJECTIVE: To assess the feasibility and safety of S-ICD implantation with monitored anesthesia care (MAC) versus general anesthesia (GA) in a tertiary care center. METHODS: This is a single-center retrospective study of patients undergoing S-ICD implantation between October 2012 and May 2019. Patients were categorized into MAC and GA group based on the mode of anesthesia. Procedural success without escalation to GA was the primary endpoint of the study, whereas intraprocedural hemodynamics, need of pharmacological support for hypotension and bradycardia, length of the procedure, stay in the post-anesthesia care unit, and postoperative pain were assessed as secondary endpoints. RESULTS: The study comprises 287 patients with MAC in 111 and GA in 176 patients. Compared to MAC, patients in GA group were younger and had a higher body mass index. All patients had successful S-ICD implantation. Only one patient (0.9%) in the MAC group was converted to GA. Despite a similar baseline heart rate (HR) and mean arterial blood pressure (MAP) in both groups, patients with GA had significantly lower HR and MAP during the procedure and more frequently required pharmacological hemodynamic support. Length of the procedure, stay in the postanesthesia care unit, and postoperative pain was similar in both groups. CONCLUSION: This retrospective experience suggests that implantation of S-ICD is feasible and safe with MAC. Use of GA is associated with more frequent administration of hemodynamic drugs during S-ICD implantation.

Bradycardic and Antiarrhythmic Effects of the D-Limonene in Rats / Efeitos Bradicárdicos e Antiarrítmicos do D-Limoneno em Ratos

Abstract Background: D-limonene (DL) is a monoterpene and is the major component in the essential oil of citrus fruit. It presents antihyperglycemic and vasodilatation activities. Objectives: This study evaluated the cardiovascular effects and potential antiarrhythmic of DL in rats. Methods: Hemodynamic and electrocardiographic (ECG) parameters were measured in male Wistar rats, which under anesthesia had been cannulated in the abdominal aorta and lower vena cava and had electrodes subcutaneously implanted. In the in vitro approach, the heart was removed and perfused using the Langendorff technique. The significance level adopted was 5% (p < 0.05). Results: DL, in doses of 10, 20, and 40 mg/kg (i.v), produced intense and persistent bradycardia associated with hypotension. Bradycardia with prolonged QTc was observed in the ECG in vivo recording. In the in vivo model of arrhythmia induced by Bay K8644, DL (10 mg/kg) decreased the arrhythmia score from 15.33 ± 3.52 to 4.0 ± 2.64 u.a (p < 0.05, n = 4). In isolated perfused hearts, DL (10-3 M) promoted significant reductions in heart rate (from 228.6 ± 8.5 ms to 196.0 ± 9.3 bpm; p < 0.05) and left ventricular development pressure (from 25.2 ± 3.4 to 5.9 ± 1.8 mmHg; n = 5, p < 0.05). Conclusions: DL produces bradycardia and antiarrhythmic activity in rat heart.

Resumo Fundamento: O D-limoneno (DL) é um monoterpeno e o principal componente do óleo essencial de frutas cítricas. Ele apresenta atividades anti-hiperglicêmicas e vasodilatadoras. Objetivos: Este estudo avaliou os efeitos cardiovasculares e antiarrítmicos potenciais do DL em ratos. Métodos: Os parâmetros hemodinâmicos e eletrocardiográficos (ECG) foram mensurados em ratos Wistar machos que, sob anestesia, tiveram a aorta abdominal e a veia cava inferior canuladas e receberam eletrodos implantados subcutaneamente. Na abordagem in vitro, o coração foi removido e perfundido utilizando a técnica de Langendorff. O nível de significância adotado foi de 5% (p < 0,05). Resultados: DL, nas doses de 10, 20 e 40 mg/kg (i.v), produziu bradicardia intensa e persistente associada à hipotensão. A bradicardia com QTc prolongado foi observada no registro in vivo do ECG. No modelo in vivo de arritmia induzida por Bay K8644, DL (10 mg / kg) houve diminuição do escore da arritmia de 15,33 ± 3,52 para 4,0 ± 2,64 u.a (p < 0,05, n = 4). Em corações perfundidos isolados, o DL (10-3 M) promoveu reduções significativas na frequência cardíaca (de 228,6 ± 8,5 ms para 196,0 ± 9,3 bpm; p < 0,05) e na pressão desenvolvida do ventrículo esquerdo (de 25,2 ± 3,4 para 5,9 ± 1,8 mmHg; n = 5, p < 0,05). Conclusões: O DL produz bradicardia e atividade antiarrítmica no coração de ratos.

Bradycardic and Antiarrhythmic Effects of the D-Limonene in Rats.

BACKGROUND: D-limonene (DL) is a monoterpene and is the major component in the essential oil of citrus fruit. It presents antihyperglycemic and vasodilatation activities. OBJECTIVES: This study evaluated the cardiovascular effects and potential antiarrhythmic of DL in rats. METHODS: Hemodynamic and electrocardiographic (ECG) parameters were measured in male Wistar rats, which under anesthesia had been cannulated in the abdominal aorta and lower vena cava and had electrodes subcutaneously implanted. In the in vitro approach, the heart was removed and perfused using the Langendorff technique. The significance level adopted was 5% (p < 0.05). RESULTS: DL, in doses of 10, 20, and 40 mg/kg (i.v), produced intense and persistent bradycardia associated with hypotension. Bradycardia with prolonged QTc was observed in the ECG in vivo recording. In the in vivo model of arrhythmia induced by Bay K8644, DL (10 mg/kg) decreased the arrhythmia score from 15.33 ± 3.52 to 4.0 ± 2.64 u.a (p < 0.05, n = 4). In isolated perfused hearts, DL (10-3 M) promoted significant reductions in heart rate (from 228.6 ± 8.5 ms to 196.0 ± 9.3 bpm; p < 0.05) and left ventricular development pressure (from 25.2 ± 3.4 to 5.9 ± 1.8 mmHg; n = 5, p < 0.05). CONCLUSIONS: DL produces bradycardia and antiarrhythmic activity in rat heart.

Chinese Patent medicine to treat a 32-year-old man with sinus bradycardia and cardiac sinus arrests: A case report.

RATIONALE: Sinus bradycardia refers to a sinus heart rate <60 bpm. Cardiac sinus arrests refer to the omission of atrial activation caused by transient cessation of impulse generation at the sinoatrial node. Normally, drugs such as atropine, isoproterenol, dopamine, dobutamine, or epinephrine can be used for the acute treatment of bradycardia. Temporary pacing is used for treating severe symptomatic bradycardia due to a reversible cause. Permanent cardiac pacing is used for chronic therapy of bradycardia. However, for traditional Chinese medicine (TCM), benefiting qi and nourishing yin and activating blood circulation is the general principle in treatment and show remarkable curative effects. PATIENT CONCERNS: A 32-year-old man was found to have 1-degree atrioventricular block and sinus bradycardia during a physical examination. He reported suffering from palpitation and shortness of breath occasionally. An ambulatory electrocardiogram showed sinus arrhythmia, sinus bradycardia, and significant sinus arrhythmia. The minimum heart rate was 33 bpm (beats per minute). The number of sinus arrest was 42 and the maximum RR interval was 2216 ms. DIAGNOSES: The patient was diagnosed with bradyarrhythmia in Western medicine and "palpitation" in TCM. INTERVENTIONS: The patient was treated with methods of benefiting qi and nourishing yin and activating blood circulation along with warming yan for nearly 5 months. CPM (Chinese patent medicine) such as Yixinshu capsule, Bingdouling oral liquid, Zhenyuan capsule, Zhibaidihuang pills were used for treatment. At the same time, he was suggested to change his lifestyles including falling asleep before 10:00 PM and abandoning spicy diets. OUTCOMES: The symptoms of palpitation and shortness of breath disappeared. The minimum heart rate increased from 33 to 42 bpm and sinus arrests did not occur. The maximum RR interval decreased from 2216 to 1650 ms and the remarkable sinus arrhythmia had improved obviously. LESSONS: This case report shows that TCM can be an effective alternative therapy for sinus bradycardia and cardiac sinus arrests. CPM may have been a successful intervention in arrhythmias.

Fluoxetine oral treatment discloses 5-HT1D receptor as vagoinhibitor of the cardiac cholinergic neurotransmission in rat.

Although depression and cardiovascular diseases are related, the role of antidepressants such as fluoxetine (increasing serotonin levels) within cardiac regulation remains unclear. We aimed to determine whether fluoxetine modifies the pharmacological profile of serotonergic influence on vagal cardiac outflow. Rats were treated with fluoxetine (10 mg/kg per day; p.o.) for 14 days or equivalent volumes of drinking water (control group); then, they were pithed and prepared for vagal stimulation. Bradycardic responses were obtained by electrical stimulation of the vagal fibers (3, 6, and 9 Hz) or i.v. acetylcholine (ACh; 1, 5, and 10 µg/kg). The i.v. administration of 5-hydroxytryptamine (5-HT; 10 and 50 µg/kg) inhibited the vagally induced bradycardia. 5-CT (5-HT1/7 agonist) and L-694,247 (5-HT1D agonist) mimicked the serotonin inhibitory effect while α-methyl-5-HT (5-HT2 agonist) was devoid of any action. SB269970 (5-HT7 antagonist) did not abolish 5-CT inhibitory action on the electrically induced bradycardia. Pretreatment with LY310762 (5-HT1D antagonist) blocked the effects induced by L-694,247 and 5-CT. 5-HT and 5-CT failed to modify the bradycardia induced by exogenous ACh. Our outcomes suggest that fluoxetine treatment modifies 5-HT modulation on heart parasympathetic neurotransmission in rats, evoking inhibition of the bradycardia via prejunctional 5-HT1D in pithed rats.

Modulation of Neurally Mediated Vasodepression and Bradycardia by Electroacupuncture through Opioids in Nucleus Tractus Solitarius.

Stimulation of vagal afferent endings with intravenous phenylbiguanide (PBG) causes both bradycardia and vasodepression, simulating neurally mediated syncope. Activation of µ-opioid receptors in the nucleus tractus solitarius (NTS) increases blood pressure. Electroacupuncture (EA) stimulation of somatosensory nerves underneath acupoints P5-6, ST36-37, LI6-7 or G37-39 selectively but differentially modulates sympathoexcitatory responses. We therefore hypothesized that EA-stimulation at P5-6 or ST36-37, but not LI6-7 or G37-39 acupoints, inhibits the bradycardia and vasodepression through a µ-opioid receptor mechanism in the NTS. We observed that stimulation at acupoints P5-6 and ST36-37 overlying the deep somatosensory nerves and LI6-7 and G37-39 overlying cutaneous nerves differentially evoked NTS neural activity in anesthetized and ventilated animals. Thirty-min of EA-stimulation at P5-6 or ST36-37 reduced the depressor and bradycardia responses to PBG while EA at LI6-7 or G37-39 did not. Congruent with the hemodynamic responses, EA at P5-6 and ST36-37, but not at LI6-7 and G37-39, reduced vagally evoked activity of cardiovascular NTS cells. Finally, opioid receptor blockade in the NTS with naloxone or a specific µ-receptor antagonist reversed P5-6 EA-inhibition of the depressor, bradycardia and vagally evoked NTS activity. These data suggest that point specific EA stimulation inhibits PBG-induced vasodepression and bradycardia responses through a µ-opioid mechanism in the NTS.

Molecular Mechanisms of Increased Heart Rate in Shenxianshengmai-treated Bradycardia Rabbits.

BACKGROUND: The molecular mechanisms of Shenxianshengmai (SXSM), a traditional Chinese medicine, on bradycardia have been incompletely understood. The study tried to investigate the gene expression profile and proteomics of bradycardia rabbits' hearts after SXSM treatment. METHODS: Twenty-four adult rabbits were randomly assigned in four groups: sham, model, model plus SXSM treatment, and sham plus SXSM treatment groups. Heart rate was recorded in all rabbits. Then, total RNA of atria and proteins of ventricle were isolated and quantified, respectively. Gene expression profiling was conducted by gene expression chip, and quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed to confirm the results of gene expression chip. We used isobaric tags for elative and absolute quantitation and Western blotting to identify altered proteins after SXSM treatment. RESULTS: There was a constant decrease in the mean heart rate (32%, from 238 ± 6 beats/min to 149 ± 12 beats/min) after six weeks in model compared with that in sham group. This effect was partially reversed by 4-week SXSM treatment. Complementary DNA microarray demonstrated that the increased acetylcholinesterase and reduced nicotinic receptor were take responsibility for the increased heart rate. In addition, proteins involved in calcium handling and signaling were affected by SXSM treatment. Real-time RT-PCR verified the results from gene chip. Results from proteomics demonstrated that SXSM enhanced oxidative phosphorylation and tricarboxylic acid (TCA) cycle in ventricular myocardium to improve ATP generation. CONCLUSIONS: Long-term SXSM stimulates sympathetic transmission by increasing the expression of acetylcholinesterase and reduces the expression of nicotinic receptor to increase heart rate. SXSM also restored the calcium handling genes and altered genes involved in signaling. In addition, SXSM improves the ATP supply of ventricular myocardium by increasing proteins involved in TCA cycle and oxidation-respiratory chain.

Efficacy and effectiveness of anti-digoxin antibodies in chronic digoxin poisonings from the DORA study (ATOM-1).

CONTEXT: We hypothesized that in chronic digoxin toxicity, anti-digoxin antibodies (Fab) would be efficacious in binding digoxin, but this may not translate into improved clinical outcomes. OBJECTIVE: This study aims to investigate changes in free digoxin concentrations and clinical effects on heart rate and potassium concentrations in chronic digoxin poisoning when anti-digoxin Fab are given. MATERIALS AND METHODS: This is a prospective observational study. Patients were recruited if they have been treated with anti-digoxin Fab for chronic digoxin poisoning. Data was entered into a standardised prospective form, supplemented with medical records. Their serum or plasma was collected, analysed for free and bound digoxin and free anti-digoxin Fab concentrations. RESULTS: From September 2013 to February 2015, 36 patients (median age, 78 years; 22 females) were recruited from 18 hospitals. Median heart rate (HR) was 49 beats/min. Initial median digoxin and potassium concentrations were 4.7 nmol/L (3.6 µg/L) (range: 2.3-11.2 nmol/L) and 5.3 mmol/L (range: 2.9-9.2 mmol/L) respectively. Beta-blockers (n = 18), calcium antagonists (n = 6), spironolactone and/or angiotensin blocking agents (n = 24) were also used concomitantly. Renal impairment and gastrointestinal symptoms were present in 31 (86%) and 22 (63%) patients respectively. Five patients died from conditions unrelated to digoxin toxicity. Median change in HR was 8 beats/min post-Fab with no effect on blood pressure; they were 4, 10 and 17 beats/min for the 1, 2 and ≥3 vials of anti-digoxin Fab groups respectively. Concomitant treatments with potassium lowering agents (12/36) and inotropic drugs (7/36) were used. Gastrointestinal effects resolved in all 22 patients. The median decrease for potassium was 0.3 mmol/L. Digoxin concentration reduced from 3.8 to 0 nmol/L post-Fab. There was a rebound observed in the free digoxin concentration in 25 patients but none had associated clinical deterioration. CONCLUSIONS: One to two vials of anti-digoxin Fab initially bound all free digoxin confirming Fab efficacy. However, this was associated with only a moderate improvement in HR and potassium, suggesting bradyarrhythmia and hyperkalaemia may be from other co-morbidities.

Calcium channel antagonist and beta-blocker overdose: antidotes and adjunct therapies.

Management of cardiovascular instability resulting from calcium channel antagonist (CCB) or beta-adrenergic receptor antagonist (BB) poisoning follows similar principles. Significant myocardial depression, bradycardia and hypotension result in both cases. CCBs can also produce vasodilatory shock. Additionally, CCBs, such as verapamil and diltiazem, are commonly ingested in sustained-release formulations. This can also be the case for some BBs. Peak toxicity can be delayed by several hours. Provision of early gastrointestinal decontamination with activated charcoal and whole-bowel irrigation might mitigate this. Treatment of shock requires a multimodal approach to inotropic therapy that can be guided by echocardiographic or invasive haemodynamic assessment of myocardial function. High-dose insulin euglycaemia is commonly recommended as a first-line treatment in these poisonings, to improve myocardial contractility, and should be instituted early when myocardial dysfunction is suspected. Catecholamine infusions are complementary to this therapy for both inotropic and chronotropic support. Catecholamine vasopressors and vasopressin are used in the treatment of vasodilatory shock. Optimizing serum calcium concentration can confer some benefit to improving myocardial function and vascular tone after CCB poisoning. High-dose glucagon infusions have provided moderate chronotropic and inotropic benefits in BB poisoning. Phosphodiesterase inhibitors and levosimendan have positive inotropic effects but also produce peripheral vasodilation, which can limit blood pressure improvement. In cases of severe cardiogenic shock and/or cardiac arrest post-poisoning, extracorporeal cardiac assist devices have resulted in successful recovery. Other treatments used in refractory hypotension include intravenous lipid emulsion for lipophilic CCB and BB poisoning and methylene blue for refractory vasodilatory shock.

ECG in neonate mice with spinal muscular atrophy allows assessment of drug efficacy.

Molecular technologies have produced diverse arrays of animal models for studying genetic diseases and potential therapeutics. Many have neonatal phenotypes. Spinal muscular atrophy (SMA) is a neuromuscular disorder primarily affecting children, and is of great interest in translational medicine. The most widely used SMA mouse models require all phenotyping to be performed in neonates since they do not survive much past weaning. Pre-clinical studies in neonate mice can be hindered by toxicity and a lack of quality phenotyping assays, since many assays are invalid in pups or require subjective scoring with poor inter-rater variability. We find, however, that passive electrocardiography (ECG) recording in conscious 11-day old SMA mice provides sensitive outcome measures, detecting large differences in heart rate, cardiac conduction, and autonomic control resulting from disease. We find significant drug benefits upon treatment with G418, an aminoglycoside targeting the underlying protein deficiency, even in the absence of overt effects on growth and survival. These findings provide several quantitative physiological biomarkers for SMA preclinical studies, and will be of utility to diverse disease models featuring neonatal cardiac arrhythmias.

Therapeutical effect of Radix Aconiti and Astragalus extracts on models of experimental bradycardia animal.

The antibradycardia effect of extract of RAE (Radix Aconiti and Astragalus) on bradycardia animal models were evaluated. Bradycardia rat model was induced by amiodarone or propranolol, and sick sinus syndrome (SSS) rabbit model was induced by chemical stimulation on surface of sinus node. The heart rates of the animal models were calculated according to ECG recording. The value of sino-atrial conduction time (SACT) and correcting sinus node recovery time (CSNRT) of SSS rabbit model were measured by multi-channel physiological recorder. The blood flow of aorta and coronary the diabolic pressure of normal rat hearts in vitro were measured. Treatment with RAE could increase the heart rate of bradycardia animals induced by amiodarone, propranolol, or SSS rabbit model significantly. Treatment with RAE could decrease in the value of SACT and CSNRT of SSS rabbit model. Moreover, treatment with RAE could increase the blood flow of aorta and coronary and could decrease diabolic pressure of normal rat hearts in vitro. RAE has heart-rate-increasing effect, which might be related to its ameliorating the autorhythmicity of sinus node and improving the sino-atrial conductive function. Moreover, RAE could ameliorate cardiac blood supply and enhance cardiac function.

Synergistic restoring effects of isoproterenol and magnesium on KCNQ1-inhibited bradycardia cell models cultured in microelectrode array.

OBJECTIVES: Bradycardia is caused by loss-of-function mutations in potassium channels that regulate phase 3 repolarization of the cardiac action potential. The purpose of this study is to monitor the effects of potassium channel (KCNQ1) inhibition and to evaluate the effects of isoproterenol (ISO) and MgSO4 in restoring sinus rhythm in atrial cells. METHODS: Microelectrode array was used to analyze conduction velocity, voltage amplitude and cycle length of atrial cells (HL-1). A combination of ISO and MgSO4 was used to restore sinus rhythm in these cells. RESULTS: mRNA expression levels of KCNQ1 (42.2 vs. 100%, p < 0.0001), connexin 43 (29.6 vs. 100%, p = 0.0033), atrial natriuretic peptide (31.0 vs. 100%, p = 0.0030), cardiac actin (38.2 vs. 100%, p < 0.0001) and α-myosin heavy chain (31.2 vs. 100%, p = 0.00254) were significantly lower in the KCNQ1 gene-inhibited group compared to the control group. When treated with MgSO4 (1 mM) and ISO (10 µM), conduction velocity (0.0208 ± 0.0036 vs. 0.0086 ± 0.0014 m/s, p = 0.0004) and voltage amplitude (1,210.78 ± 65.81 vs. 124.1 ± 13.30 µV, p < 0.0001) were higher, and cycle length (431.55 ± 2.05 vs. 1,015.15 ± 4.31 ms, p < 0.0001) was shorter than in the gene-inhibited group. CONCLUSION: Inhibition of sinus rhythm in the bradycardia cell model was recovered by treatment with ISO and MgSO4, demonstrating the potency of combination therapy in the treatment of bradycardia.