Initial studies on the implanting sites of high and low ventricular septa using leadless cardiac pacemakers.

OBJECTIVE: To study the safety and electrical characteristics of various implanting sites of the Micra pacemaker. METHOD: A total of 15 patients from Beijing Anzhen Hospital, Capital Medical University, were included, who were implanted with Micra leadless pacemakers and allocated to either the high ventricular septum group (eight patients) or the low ventricular septum group (seven patients) based on their individual patient factors and clinical conditions. The baseline of the patients, the implanting area, the electrocardiogram change after implantation, the implantation data, the threshold, R wave, impedance, and the date of the 1-month follow-up were then analyzed. With all of the data, the characteristics of different implantation sites of the Micra pacemaker were determined. RESULTS: Overall, the thresholds were low at implantation and remained stable over the 1-, 3-, 6-month, 1-, 2-, 3-, and 4-year follow-ups. On comparing the two groups, there was no difference in QRS duration at pacing (140.00 [40.00] ms vs. 179.00 [50.00] ms), threshold at implantation (0.38 [0.22] mV vs. 0.63 [1.00] mV), R wave at implantation ([10.85 ± 4.71] V vs. [7.26 ± 2.98] V), or impedance at implantation ([906.25 ± 162.39] Ω vs. [750.00 ± 173.40] Ω). While the difference in QRS duration between the two groups was not significant, the QRS duration of the high ventricular septum group exhibited a reduced tendency compared with that of the low ventricular group. The corrected QT interval during pacing exhibited a significant difference (440.00 [80.00] ms vs. 520.00 [100.00] ms; p < .05). For the 1-, 3-, 6-month, 1-, 2-, 3-, and 4-year follow-ups, there was no difference between the threshold of the high ventricular septum group and that of the low ventricular septum group (p > .05). CONCLUSION: High ventricular septum pacing appears to be a safe site for implantation of the Micra pacemaker. It could entail a shorter QRS duration at pacing and could be more physiological than low ventricular septum pacing.

CHA2DS2-VASc score as a prognostic indicator in patients with atrial fibrillation undergoing coronary stenting.

BACKGROUND: Patients with atrial fibrillation (AF) and coronary stenting had a poor prognosis. This study aimed to assess the accuracy of CHA2DS2-VASc score for predicting and grading adverse clinical outcomes in this population. METHODS: We reviewed the clinical data of all patients with previously documented nonvalvular AF who underwent coronary stenting between January 2010 and June 2015 in 12 hospitals of Beijing, China. The study population was divided into three groups: 1) Low CHA2DS2-VASc score, ≦ 2 points, 2) Intermediate score, 3-4 points, and 3) High score, ≧ 5 points. Major adverse cardiac/cerebrovascular events (MACCE) were defined as a composite of all-cause death, nonfatal myocardial infarction, repeat revascularization and ischemic stroke/systemic thromboembolism (IS/SE). RESULTS: A total of 2394 patients (men: 72.3% vs. women: 27.7%, median age: 67 years) were included, with the CHA2 DS2-VASc score of 3.6 ± 1.6. The median follow-up duration was 36.2 months. All-cause mortality increased 3 folds from the low score (4.8%) to the high score group (15.8%). The high score group had more IS/SE (7.4%) and MACCE (26.3%). The CHA2 DS2-VASc score ≧ 5 points was independently associated with all-cause death (hazard ratio [HR]: 2.303, 95% confidence interval [CI]: 1.492- 3.555), IS/SE (HR: 4.169, 95% CI: 2.216-7.845) and MACCE (HR: 1.468, 95% CI: 1.113-1.936) on multivariate Cox proportional hazards regression. The area under the receiver operating characteristic curve of the CHA2DS2-VASc score was 0.644 (95% CI: 0.624-0.663) for all-cause death, 0.647 (95% CI: 0.627-0.666) for IS/SE, and 0.592 (95% CI: 0.572-0.611) for MACCE. DISCUSSION: CHA2DS2-VASc score was a reliable prognostic indicator in patients with AF and coronary stenting.

Congenitally corrected transposition of the great arteries and implantation of a leadless pacemaker: a case report.

BACKGROUND: Congenitally corrected transposition of the great arteries (ccTGA) is a rare cardiac anomaly and can lead to abnormal electrical activity of the heart. The implant of a pacemaker in such patients is more complicated than conventional operations. This case report of an adult with ccTGA who had a leadless pacemaker implant will provide a reference for diagnosing and treating such patients. CASE PRESENTATION: A 50-year-old male patient was admitted to hospital having experienced intermittent vision loss for a month. An electrocardiogram and Holter monitoring showed intermittent third-degree atrioventricular block, and echocardiography, cardiac computed tomography and cardiac magnetic resonance imaging confirmed a diagnosis of ccTGA. A leadless pacemaker was successfully implanted into the patient's anatomical left ventricle, and the postoperative parameters were stable. CONCLUSION: Implanting a leadless pacemaker into a patient with a rare anatomical and electrophysiological abnormality, such as ccTGA, is feasible and efficacious, but preoperative imaging evaluation is of considerable importance.

Conditional survival probability of distant-metastatic hepatocellular carcinoma: A population-based study.

BACKGROUND: The prognosis of many patients with distant metastatic hepatocellular carcinoma (HCC) improved after they survived for several months. Compared with traditional survival analysis, conditional survival (CS) which takes into account changes in survival risk could be used to describe dynamic survival probabilities. AIM: To evaluate CS of distant metastatic HCC patients. METHODS: Patients diagnosed with distant metastatic HCC between 2010 and 2015 were extracted from the Surveillance, Epidemiology and End Results database. Univariate and multivariate Cox regression analysis were used to identify risk factors for overall survival (OS), while competing risk model was used to identify risk factors for cancer-specific survival (CSS). Six-month CS was used to calculate the probability of survival for an additional 6 mo at a specific time after initial diagnosis, and standardized difference (d) was used to evaluate the survival differences between subgroups. Nomograms were constructed to predict CS. RESULTS: Positive α-fetoprotein expression, higher T stage (T3 and T4), N1 stage, non-primary site surgery, non-chemotherapy, non-radiotherapy, and lung metastasis were independent risk factors for actual OS and CSS through univariate and multivariate analysis. Actual survival rates decreased over time, while CS rates gradually increased. As for the 6-month CS, the survival difference caused by chemotherapy and radiotherapy gradually disappeared over time, and the survival difference caused by lung metastasis reversed. Moreover, the influence of age and gender on survival gradually appeared. Nomograms were fitted for patients who have lived for 2, 4 and 6 mo to predict 6-month conditional OS and CSS, respectively. The area under the curve (AUC) of nomograms for conditional OS decreased as time passed, and the AUC for conditional CSS gradually increased. CONCLUSION: CS for distant metastatic HCC patients substantially increased over time. With dynamic risk factors, nomograms constructed at a specific time could predict more accurate survival rates.

Predictive models for adverse clinical outcomes in Chinese patients with atrial fibrillation undergoing percutaneous coronary intervention with stenting.

OBJECTIVE: This study aimed to evaluate predictors for adverse cardiovascular outcomes in patients with atrial fibrillation (AF) undergoing coronary stenting. METHODS: We retrospectively recruited consecutive patients with previously documented non-valvular AF who underwent coronary stenting between January 2010 and June 2015 in 12 hospitals of Beijing, China. Major adverse cardiac/cerebrovascular events (MACCE) were a composite of all-cause death, non-fatal myocardial infarction, repeat revascularization, and ischaemic stroke/systemic thromboembolism (IS/STE). Major bleeding referred to grade 2 or higher of Bleeding Academic Research Consortium criteria. RESULTS: A total of 2394 patients (men: 72.3% vs. women: 27.7%, median age: 67 years) were included. The CHA2DS2-VASc and HAS-BLED were 3.6 ± 1.6 and 1.9 ± 0.7, respectively. The median follow-up duration was 36.2 months. There were 230 (9.6%) deaths, 96 (4.0%) IS/STE, 426 (17.8%) MACCE, and 72 (3.0%) major bleeding. Multivariate Cox regression yielded predictive models for (1) all-cause death: diabetes, prior myocardial infarction, chronic kidney disease (CKD), ST-segment elevation myocardial infarction (STEMI) at presentation, heart failure, no use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and statins; (2) IS/STE: advanced age, prior history of ischaemic stroke and intracranial haemorrhage; (3) MACCE: prior history of myocardial infarction and ischaemic stroke, CKD, STEMI, heart failure, and no statin use; (4) major bleeding: prior major bleeding, prior myocardial infarction, CKD and use of oral anticoagulants. CONCLUSION: Chinese patients with AF and coronary stenting had high mortality and incidence of MACCE. We compiled separate predictive models for all-cause death, IS/STE, MACCE, and major bleeding.

Sex difference in clinical outcomes of Chinese patients with atrial fibrillation and coronary stenting according to age.

OBJECTIVE: Sex differences in the clinical outcomes of patients with atrial fibrillation (AF) and coronary stenting should be assessed according to age. METHODS: We analyzed the clinical data of all patients with nonvalvular AF who underwent coronary stenting between January 2010 and June 2015 in 12 hospitals of Beijing, China. RESULTS: A total of 2,146 patients (71.8% men and 28.2% women) were included in the study. The mean age of the patients was 66.6±9.4 years. Women in this study were older and had higher prevalence of hypertension, diabetes, chronic kidney disease (CKD), and anemia. Smoking history was found to be higher in men, and women were less likely to be current smokers. The mean follow-up duration was 39.7 months. Women younger than 65 years had a remarkably higher mortality (11.2% vs. 5.3%, p=0.012) and a significantly lower rate of repeat revascularization (1.6% vs. 6.3%, p=0.034) than men. Female gender remained an independent predictor for all-cause mortality [hazard ratio (HR)=2.03, 95% confidence interval (CI): 1.09-3.79, p=0.025], along with heart failure (HR=3.64, 95% CI: 2.02-6.57, p<0.001) and CKD (HR=2.46, 95% CI: 1.09-5.57, p=0.031) after multivariate regression analysis. No significant difference was noted between men and women with regard to mortality, ischemic events, and major bleeding in elderly patients. CONCLUSION: In Chinese patients younger than 65 years with AF and coronary stenting, female gender was independently associated with increased mortality; men were more likely to receive repeat revascularization possibly due to the current smoking. Whether it was a biological difference or a recognition disparity of the disease between men and women warrants further investigation.

[Phospholamban antisense RNA transfer attenuates post-infarction remodeling and preserves cardiac functions].

OBJECTIVE: To investigate whether the gene transfer of phospholamban antisense RNA could inhibit remodeling and preserve cardiac function after myocardial infarction. METHODS: Wistar rats received a ligation of left coronary with a direct intramyocardial injection of phospholamban antisense RNA eukaryote vector PcDNA4-asPLB. The cardiac function, hemodynamics and ventricular geometry of three groups (shame, saline injection and PcDNA4-asPLB injection) were studied by echocardiography and left ventricle hemodynamic recording. The levels of phospholamban (PLB) and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a) were analyzed by Western blot and the expressions of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) examined by RT-PCR. The histological study was performed to evaluate the collage content and cardiomyocyte fiber size. RESULTS: The PcDNA4-asPLB injection group had significantly better systolic cardiac function and diastolic function [LVEF (39.4 +/- 7.8)% vs (30.9 +/- 7.4)%, P < 0.05; dp/dt Max (1545 +/- 127) mm Hg x s(-1) vs (1172 +/- 91) mm Hg x s(-1), P < 0.05)]. Compared with saline injection, the PLB expression was inhibited by 50% in PcDNA4-asPLB injection group (PLB/beta-actin ratio, 0.28 +/- 0.07 vs 0.57 +/- 0.11, P < 0.05) and the function of SERCA2a was enhanced [(1.47 +/- 0.21) micromol x min(-1) x g(-1) protein vs (0.34 +/- 0.13) micromol x min(-1) x g(-1) protein, P < 0.05]. The expressions of ANP and BNP in the saline injection group were elevated as compared to those in the PcDNA4-asPLB injection group. Histological study also showed that the collage density and the cardiomyocyte fiber size in the saline injection group were worse than those in the PcDNA4-asPLB injection group. CONCLUSION: Intramyocardial injection of phospholamban antisense RNA eukaryote vector PcDNA4-asPLB after myocardial infarction results in PLB expression inhibition, attenuates ventricular remodeling and improves systolic and diastolic cardiac functions.

Initial experience with ablation of the innervation surrounding sinus and atrioventricular nodes to treat paroxysmal bradyarrhythmia.

BACKGROUND: The symptomatic bradyarrhythmia is Class I indication for pacing therapy which is not a radical cure. The present study aimed to assess the feasibility and to present the initial results of the restricted ablation of the parasympathetic innervation surrounding sinus and atrioventricular (AV) nodes for treating patients with bradyarrhythmia. METHODS: A total of 13 patients with cardiogenic syncope were included from May 2008 to June 2015. Under the guidance of fluoroscopy and /or three-dimensional geometry by 64-slice spiral computed tomography, atrial activation sequence in sinus rhythm was mapped. Chamber geometry was reconstructed manually or automatically using the Niobe II magnetic navigation system integrated with the CARTO-remote magnetic technology (RMT) system. Cardioneuroablation was targeted at the high-amplitude fractionated electrograms surrounding the regions of His bundle and the site with the earliest activation in sinus rhythm. Areas surrounding the sinus node, AV node, and the phrenic nerve were avoided. RESULTS: Thirteen patients completed the studies. Ablation was successfully performed in 12 patients and failed in one. The high-frequency potential was recorded in atrial electrograms surrounding the sinus or AV nodes in all the patients and disappeared in 15 s after radiofrequency applications. The vagal reaction was observed before the improvement of the sinus and AV node function. No complications occurred during the procedures. Patients were followed up for a mean of 13.0 ±â€Š5.9 months. During the follow up ten patients remained free of symptoms, and two patients had a permanent cardiac pacemaker implanted due to spontaneous recurrence of syncope. The heart rate of post-ablation was higher than pre-ablation (69.0 ±â€Š11.0 vs. 49.0 ±â€Š10.0 beats/min, t = 4.56, P = 0.008). The sinus node recovery time, Wenckebach block point, and atrium-His bundle interval were significantly shorter after ablation (1386.0 ±â€Š165.0 vs. 921.0 ±â€Š64.0 ms, t = 7.45, P = 0.002; 590.0 ±â€Š96.0 vs. 464.0 ±â€Š39.0 ms, t = 2.38, P = 0.023; 106.0 ±â€Š5.0 vs. 90.0 ±â€Š12.0 ms, t = 9.80, P = 0.013 before and after ablation procedure, respectively). CONCLUSIONS: Ablation of sinoatrial and AV nodal peripheral fibrillar myocardium electrical activity might provide a new treatment to ameliorate paroxysmal sinus node dysfunction, high degree AV block, and vagal-mediated syncope.

[Study on changes of content of Tannin in Nodus Nelumbinis Rhizomatis Charcoal].

OBJECTIVE: To determine changes of content of Tannin in different Nodus Nelumbinis Rhizomatis Charcoal. METHODS: The content of Tannin of Nodus Nelumbinis Rhizomatis Charcoal was detected by UV and colorimetric method. RESULTS: The content of tannin in standard sample was the highest. CONCLUSION: It should be studied whether the tannin of Nodus Nelumbinis Rhizomatis Charcoal is the active ingredients of hemostasis.

[Polymorphic Hind III restriction site of the Y chromosome and essential hypertension in Chinese Han People].

OBJECTIVE: To examine whether there is an association essential hypertension pressure and a polymorphic Hind III biallelic marker in the non-recombining region of Y chromosome in Chinese Han people. METHODS: Peripheral blood samples were collected from 402 males with essential hypertension pressure and 455 age- and body height-matched healthy males as control group. Genomic DNA was extracted from the white blood cells. Segments of polymorphic Hind III restriction site of the Y chromosome were amplified from the genomic DNA by polymerase chain reaction (PCR). The PCR products were restricted with 10 U of Hind III overnight at 37 degrees C. The digested products were subjected to electrophoresis in 3% agarose gels, and stained with ethidium bromide. RESULTS: The Hind III (+) genotype was found in 58.5% of the men with essential hypertension (235/402), significantly lower than that in the healthy men (64.4%, 302/455, P = 0.02). The systolic blood pressure of the men with Hind III (+) genotype was 133.8 mm Hg +/- 25.2 mm Hg, significantly lower than that of the Hind III (-) genotype (138.0 mm Hg +/- 27.0 mm Hg, P < 0.05), and the diastolic blood pressure (DBP) of the men with Hind III (+) genotype was 83.5 mm Hg +/- 13.3 mm Hg, significantly lower than that of the men with Hind III (-) genotype (85.9 mm Hg +/- 14.4 mm Hg, P = 0.01), and the mean arterial pressure of the men with Hind III (+) genotype was 100.2 mm Hg +/- 16.5 mm Hg, significantly lower than that of the of the men with Hind III (+) genotype was (103.3 mm Hg +/- 17.6 mm Hg, P = 0.01). CONCLUSION: Polymorphic Hind III restriction site of the Y chromosome is associated with essential hypertension in Chinese Han people.

[Efficacy and safety of the coronary intervention therapy to prevent electrical storm in patients with coronary artery disease but without myocardial infarction].

OBJECTIVE: To study the efficacy and safety of the coronary interventional therapy to prevent electrical storm (ES) in patients with coronary artery diseases (CAD) but without myocardial infarction or ischemic cardiomyopathy. METHODS: Coronary angiography and stent implantation were performed in CAD patients with ES as major symptom, according to the standardized methods. Holter Electrocardiography was recorded regularly during follow-up. RESULTS: Six patients, five male and one female, with mean age of 49.5 +/- 9.1 year-old, were hospitalized. In 2 patients with repetitive syncope, multiple episodes of ventricular tachycardia and/or ventricular fibrillation (VF) were documented by Holter recording. One patient developed VF during exercise test. Three patients experienced chest pain and multiple episodes of cardiac arrest. Before procedure, averaged 16.5 +/- 5.3 episodes of syncope or VF were documented in 6 patients. Coronary angiography revealed severe one or multi-vessel diseases. Total 8 stents, including 3 drug-eluting stents, were implanted in 6 patients. Symptom, ST-T changes and ES disappeared after coronary stenting. During 4 month to 6.5 year follow-up (mean 47.7 +/- 30.7 months), ES was not documented, no appropriated shock occurred in patients with implantable defibrillator for 6.5 years. CONCLUSION: In CAD patients without myocardial infarction, coronary stenting can relieve the ischemic substrate of ES, hence prevents sudden death effectively.

Attenuated plaque is associated with plaque prolapse accompanied by cardiac enzyme elevation after drug-eluting stent implantation.

OBJECTIVES: This study aimed to evaluate the relationship between grayscale intravascular ultrasound-attenuated plaque (AP) and poststenting plaque prolapse (PP) as well as their influence on creatine kinase-myocardial band (CK-MB) elevation after drug-eluting stent (DES) implantation. BACKGROUND: The relationship between baseline AP and poststenting PP and their impacts on percutaneous coronary intervention (PCI) are not well known. PATIENTS AND METHODS: A total of 141 single, native, de-novo coronary lesions in 141 patients with normal pre-PCI CK-MB levels who underwent intravascular ultrasound before and after DES implantation were studied. RESULTS: AP was found in 72 (51.1%) lesions and PP occurred in 43 (30.5%) lesions. Baseline AP was associated with greater plaque area, lesion eccentricity, and positive remodeling, and was associated with higher frequency of poststenting PP (47.2 vs. 13.0%, P<0.001) as well as greater poststenting PP volume (2.2±1.3 vs. 1.9±1.1 mm, P=0.045). Elevated CK-MB levels were observed in 34 (24.1%) lesions and significantly more frequently in patients with baseline AP and poststenting PP than without both of these findings. Multivariate analysis indicated that AP with PP was the predictor of post-PCI CK-MB elevation. CONCLUSION: Baseline AP was associated with high-risk characteristics, higher frequency, and greater volume of poststenting PP accompanied by CK-MB elevation in patients with DES implantation.

Ultrasonic destruction of albumin microbubbles enhances gene transfection and expression in cardiac myocytes.

BACKGROUND: It has been proven that ultrasonic destruction of microbubbles can enhance gene transfection efficiency into the noncardiac cells, but there are few reports about cardiac myocytes. Moreover, the exact mechanisms are not yet clear; whether the characteristic of microbubbles can affect the gene transfection efficiency or not is still controversial. This study was designed to investigate whether the ultrasound destruction of gene-loaded microbubbles could enhance the plasmids carried reporter gene transfection in primary cultured myocardial cell, and evaluate the effects of microbubbles characteristics on the transgene expression in cardiac myocytes. METHODS: The ß-galactosidase plasmids attached to the two types of microbubbles, air-contained sonicated dextrose albumin (ASDA) and perfluoropropane-exposed sonicated dextrose albumin (PESDA) were prepared. The gene transfection into cardiac myocytes was performed in vitro by naked plasmids, ultrasound exposure, ultrasonic destruction of gene-loaded microbubbles and calcium phosphate precipitation, and then the gene expression and cell viability were analyzed. RESULTS: The ultrasonic destruction of gene-loaded microbubbles enhanced gene expression in cardiac myocytes compared with naked plasmid transfection ((51.95 ± 2.41) U/g or (29.28 ± 3.65) U/g vs. (0.84 ± 0.21) U/g, P < 0.01), and ultrasonic destruction PESDA resulted in more significant gene expression than ASDA ((51.95 ± 2.41) U/g vs. (29.28 ± 3.65) U/g, P < 0.05). Ultrasonic destruction of microbubbles during calcium phosphate precipitation gene transfection enhanced ß-galactosidase activity nearly 8-fold compared with calcium phosphate precipitation gene transfection alone ((111.35 ± 11.21) U/g protein vs. (14.13 ± 2.58) U/g protein, P < 0.01). Even 6 hours after calcium phosphate precipitation gene transfection, ultrasound-mediated microbubbles destruction resulted in more intense gene expression ((35.63 ± 7.65) U/g vs. (14.13 ± 2.58) U/g, P < 0.05). CONCLUSIONS: Ultrasonic destruction of microbubbles might be a promising method for the delivery of non-viral DNA into cardiac myocytes, and the gene tranfection is related to the characteristics of microbubbles.