Antimicrobial Activity of Apidermin 2 from the Honeybee Apis mellifera.

Apidermins (APDs) are known as structural cuticular proteins in insects, but their additional roles are poorly understood. In this study, we characterized the honeybee, Apis mellifera, APD 2 (AmAPD 2), which displays activity suggesting antimicrobial properties. In A. mellifera worker bees, the AmAPD 2 gene is transcribed in the epidermis, hypopharyngeal glands, and fat body, and induced upon microbial ingestion. Particularly in the epidermis of A. mellifera worker bees, the AmAPD 2 gene showed high expression and responded strongly to microbial challenge. Using a recombinant AmAPD 2 peptide, which was produced in baculovirus-infected insect cells, we showed that AmAPD 2 is heat-stable and binds to live bacteria and fungi as well as carbohydrates of microbial cell wall molecules. This binding action ultimately induced structural damage to microbial cell walls, which resulted in microbicidal activity. These findings demonstrate the antimicrobial role of AmAPD 2 in honeybees.

Comparison of the gut microbiome of sacbrood virus-resistant and -susceptible Apis cerana from South Korea.

Honey bees are important pollinators for the conservation of the ecosystem and agricultural products and provide a variety of products important for human use, such as honey, pollen, and royal jelly. Sacbrood disease (SD) is a devastating viral disease in Apis cerana; an effective preventive measure for SD is urgently needed. In this study, the relationship between the gut microbiome of honey bees and SD was investigated by pyrosequencing. Results revealed that sacbrood virus (SBV)-resistant A. cerana strains harbour a unique acetic acid bacterium, Bombella intestini, and the lactic acid bacteria (LAB) Lactobacillus (unclassified)_uc, Bifidobacterium longum, B. catenulatum, Lactococcus lactis, and Leuconostoc mesenteroides in larvae and Hafnia alvei, B. indicum, and the LAB L. mellifer and Lactobacillus HM215046_s in adult bees. Changes in the gut microbiome due to SBV infection resulted in loss of bacteria that could affect host nutrients and inhibit honey bee pathogens, such as Gilliamella JFON_s, Gilliamella_uc, Pseudomonas putida, and L. kunkeei in A. cerana larvae and Frischella_uc, Pantoea agglomerans, Snodgrassella_uc, and B. asteroides in adult bees. These findings provide important information for the selection of probiotics for A. cerana larvae and adults to prevent pathogenic infections and keep honey bees healthy.

Differential Expression of Major Royal Jelly Proteins in the Hypopharyngeal Glands of the Honeybee Apis mellifera upon Bacterial Ingestion.

Honeybee vitellogenin (Vg) transports pathogen fragments from the gut to the hypopharyngeal glands and is also used by nurse bees to synthesize royal jelly (RJ), which serves as a vehicle for transferring pathogen fragments to the queen and young larvae. The proteomic profile of RJ from bacterial-challenged and control colonies was compared using mass spectrometry; however, the expression changes of major royal jelly proteins (MRJPs) in hypopharyngeal glands of the honeybee Apis mellifera in response to bacterial ingestion is not well-characterized. In this study, we investigated the expression patterns of Vg in the fat body and MRJPs 1-7 in the hypopharyngeal glands of nurse bees after feeding them live or heat-killed Paenibacillus larvae. The expression levels of MRJPs and defensin-1 in the hypopharyngeal glands were upregulated along with Vg in the fat body of nurse bees fed with live or heat-killed P. larvae over 12 h or 24 h. We observed that the expression patterns of MRJPs and defensin-1 in the hypopharyngeal glands and Vg in the fat body of nurse bees upon bacterial ingestion were differentially expressed depending on the bacterial status and the time since bacterial ingestion. In addition, the AMP genes had increased expression in young larvae fed heat-killed P. larvae. Thus, our findings indicate that bacterial ingestion upregulates the transcriptional expression of MRJPs in the hypopharyngeal glands as well as Vg in the fat body of A. mellifera nurse bees.

Single direct oral anticoagulant therapy in stable patients with atrial fibrillation beyond 1 year after coronary stent implantation.

OBJECTIVE: Optimal antithrombotic therapy in patients with atrial fibrillation (AF) beyond 1 year after coronary stent implantation has not been well established in the era of direct oral anticoagulant (DOAC). METHODS: Using Korean National Health Insurance Service data, we analysed 4294 patients with AF who were prescribed DOAC beyond 1 year after coronary stent implantation. Subjects were classified into the monotherapy group (DOAC single therapy, n=1221) or the combination therapy group (DOAC with an antiplatelet agent, n=3073). The primary ischaemic endpoint was defined as a composite of cardiovascular death, myocardial infarction, stroke or systemic thromboembolism. The secondary endpoints were all-cause death, major bleeding defined as a bleeding event requiring hospitalisation and net adverse clinical events. Propensity score matching was performed to balance baseline covariates. RESULTS: Among included patients, 94% had drug-eluting coronary stents. During a median follow-up of 19 (7-32) months, the monotherapy group had a similar risk of the primary ischaemic endpoint (HR 0.828, 95% CI 0.660 to 1.038) and all-cause death (HR 1.076, 95% CI 0.895 to 1.294) compared with the combination therapy group. Risk of major bleeding was lower in the monotherapy group (HR 0.690, 95% CI 0.481 to 0.989), which was mostly driven by reduced gastrointestinal bleeding (HR 0.562, 95% CI 0.358 to 0.883). There was no significant difference in net adverse clinical events between the two groups. CONCLUSIONS: DOAC monotherapy showed similar efficacy in preventing ischaemic events and was associated with lower major bleeding events compared with combination therapy in patients with AF beyond 1 year after coronary stent implantation.

Acute and long-term outcome of redo catheter ablation for recurrent atrial tachycardia and recurrent atrial fibrillation in patients with prior atrial fibrillation ablation.

PURPOSE: Organized atrial tachycardia (AT) accounts for a substantial proportion of recurrence after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). We sought to analyze the characteristics and long-term outcome of redo RFCA for recurrent AT compared with those for recurrent AF. METHODS: We analyzed 133 patients who underwent prior AF ablation and presented for redo RFCA procedure. Documented rhythm at recurrence was AT in 50 patients (37.6%) and AF in 83 patients (62.4%). Redo ablation was conducted using a stepwise approach in all subjects. RESULTS: Recurrent arrhythmia was more frequently a persistent type in the AT group (70.0% vs. 36.1% in the AT and AF group, respectively, p < 0.001). Fifty mappable ATs were identified in the AT group. Perimitral reentry was most common (19/50), followed by PV-related focal or reentrant tachycardia (16/50). During the redo RFCA, PV reconnection rate and linear ablation rate were similar in the two groups, while the focal target ablation tended to be conducted more frequently in the AF group (26.0% vs. 42.2%, p = 0.060). The AT group showed a higher acute success rate (92.0% vs. 75.9%, p = 0.019) and higher arrhythmia freedom during a mean of 30 months (76.0% vs. 55.4%, p = 0.030), compared with the AF group. The AT group and de novo AF type (paroxysmal) were independent predictors for higher arrhythmia freedom. CONCLUSIONS: RFCA for recurrent AT following AF ablation showed favorable acute and long-term success rates and was associated with superior procedural outcomes compared with those for recurrent AF.

Long-Term Efficacy of Prophylactic Cavotricuspid Isthmus Ablation during Atrial Fibrillation Ablation in Patients Without Typical Atrial Flutter: a Prospective, Multicentre, Randomized Trial.

BACKGROUND AND OBJECTIVES: Cavotricuspid isthmus (CTI) block is easily achieved, and prophylactic ablation can be performed during atrial fibrillation (AF) ablation. However, the previous study was too small and short-term to clarify the efficacy of this block. METHODS: Patients who underwent catheter ablation for paroxysmal AF were enrolled, and patients who had previous or induced atrial flutter (AFL) were excluded. We randomly assigned 366 patients to pulmonary vein isolation (PVI) only and prophylactic CTI ablation (PVI vs. PVI+CTI). RESULTS: There was no significant difference in procedure time between the two groups because most CTI blocks were performed during the waiting time after the PVI (176.8±72.6 minutes in PVI vs. 174.2±76.5 minutes in PVI+CTI, p=0.75). All patients were followed up for at least 18 months, and the median follow-up was 3.4 years. The recurrence rate of AF or AFL was not different in the 2 groups (25.7% in PVI vs. 25.7% in PVI+CTI, p=0.92). The recurrence rate of any AFL was not significantly different in the 2 groups (3.3% in PVI vs. 1.6% in PVI+CTI, p=0.31). The recurrence rate of typical AFL also was not different (0.5% in PVI vs. 0.5% in PVI+CTI, p=0.99). CONCLUSIONS: In this large and long-term follow-up study, prophylactic CTI ablation had no benefit in patients with paroxysmal AF without typical AFL. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02031705.

Ten-year trends in the incidence, treatment and outcomes of patients with mitral stenosis in Korea.

OBJECTIVE: Mitral stenosis increases the risk of atrial fibrillation (AF) and stroke. Large data underlying the trend in incidence, treatment and outcomes of mitral stenosis are lacking. METHODS: Based on the Health Insurance Review and Assessment Service database in Republic of Korea, patients who were diagnosed with mitral stenosis between 2007 and 2016 were enrolled. Trends in the incidence rate and changing patterns of treatment and outcome for stroke and systemic embolism and intracranial haemorrhage (ICH) were analysed. RESULTS: A total of 42 075 patients (mean age 60.7±13.5 years, 13 303 (31.6%) male) were included in the present study. The number included 27 824 (66.1%) patients with mitral stenosis and comorbid AF. The age-standardised annual incidence rate per 100 000 of mitral stenosis in Korea decreased remarkably from 10.3 to 3.6 over 10 years. The use of anticoagulation therapy increased consistently. The annual incidence of stroke and systemic embolism showed signs of plateau, while the incidence of ICH increased. CONCLUSIONS: The overall incidence rate of mitral stenosis in Korean population has decreased remarkably. As increasing the use of vitamin K antagonist, the annual incidence rate of ICH was increased but the rate of stroke incidence reached a plateau. Alternative effective anticoagulation strategy should be investigated.

Status of international normalized ratio control and treatment patterns in patients with nonvalvular atrial fibrillation taking vitamin K antagonist with or without antiplatelet therapy: Results from KORAFII registry.

BACKGROUND: Studies have shown that the concomitant use of a vitamin K antagonist (VKA) and an antiplatelet (APL) drug increased the bleeding risk and was less effective at preventing ischemic events. This study aimed to investigate the control status of international normalized ratio (INR) and the discontinuation rate of a VKA in patients taking VKA plus an APL drug compared with those taking a VKA alone. METHODS: Data were extracted from the KORean Atrial Fibrillation Investigation II registry, a multicenter noninterventional prospective observational study. Nonvalvular atrial fibrillation (NVAF) patients with CHADS 2 scores ≥ 1 who newly started (within 3 months) a VKA were enrolled and followed up for 1 year. RESULTS: A total of 866 NVAF patients (mean age, 67.7 years; 60.3% men) without a bleeding history were divided into the VKA+APL (n = 229) and VKA alone (n = 637) groups. During follow-up, mean INR level was lower in the VKA+APL group than in the VKA alone group (1.7 ± 0.8 vs 1.9 ± 0.9, P = 0.0005). INR levels were poorly controlled in both groups (66.1% and 64.7%, respectively). Patients in the VKA+APL group more frequently discontinued VKA than patients in the VKA alone group (28.8% vs 24.2%, P = 0.045). Major causes of VKA discontinuation were uncontrolled INR level and patient dissatisfaction or concerns. CONCLUSIONS: The conditions of NVAF patients were inadequately controlled with VKA with or without an APL. These findings suggest that other antithrombotic treatment options are warranted in NVAF patients to achieve INR control.

Outcomes of Direct Oral Anticoagulants in Patients With Mitral Stenosis.

BACKGROUND: Patients with mitral stenosis and atrial fibrillation (AF) require anticoagulation for stroke prevention. Thus far, all studies on direct oral anticoagulants (DOACs) have excluded patients with moderate to severe mitral stenosis. OBJECTIVES: The aim of this study was to validate the efficacy of DOACs in patients with mitral stenosis. METHODS: The study population was enrolled from the Health Insurance Review and Assessment Service (HIRA) database in the Republic of Korea, and it included patients who were diagnosed with mitral stenosis and AF and either were prescribed DOACs for off-label use or received conventional treatment with warfarin. The primary efficacy endpoint was ischemic strokes or systemic embolisms, and the safety outcome was intracranial hemorrhage. RESULTS: A total of 2,230 patients (mean age 69.7 ± 10.5 years; 682 [30.6%] males) were included in the present study. Thromboembolic events occurred at a rate of 2.22%/year in the DOAC group, and 4.19%/year in the warfarin group (adjusted hazard ratio for DOAC: 0.28; 95% confidence interval: 0.18 to 0.45). Intracranial hemorrhage occurred in 0.49% of the DOAC group and 0.93% of the warfarin group (adjusted hazard ratio for DOAC: 0.53; 95% confidence interval: 0.22 to 1.26). CONCLUSIONS: In patients with AF accompanied with mitral stenosis, DOAC use is promising and hypothesis generating in preventing thromboembolism. Our results need to be replicated in a randomized trial.

Utility of acute arrhythmia termination as an ablation endpoint for induced atrial tachyarrhythmia after complete pulmonary vein isolation during catheter ablation for persistent atrial fibrillation.

PURPOSE: The presence of inducible atrial tachyarrhythmia after pulmonary vein isolation (PVI) during radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (AF) may indicate the necessity of further substrate modification, but the optimal ablation endpoint is unknown. We sought to assess the impact of procedural termination of inducible atrial tachyarrhythmia after PVI in comparison with continued atrial tachyarrhythmia after PVI. METHODS: Among patients who underwent RFCA for persistent AF, we enrolled 93 patients who were in sinus rhythm after PVI and had inducible atrial tachyarrhythmia and 157 patients with continued atrial tachyarrhythmia after PVI. The impact of acute arrhythmia termination during further substrate modification on recurrence was compared between the two groups. RESULTS: Acute termination was achieved in 51 (54.8%) patients in the induced arrhythmia group and 61 (38.9%) in the continued arrhythmia group. During a mean 35.8 months, acute termination did not significantly reduce arrhythmia recurrence in the induced arrhythmia group (HR 0.712, 95% CI 0.400-1.266, p = 0.247), while it was associated with improved outcome in the continued arrhythmia group (HR 0.590, 95% CI 0.355-0.979, p = 0.038). Acute termination of either induced atrial tachycardia (AT) or induced AF was not associated with improved procedure outcome. Among the continued arrhythmia group, the benefit of acute termination was statistically significant in AT (HR 0.329, 95% CI 0.108-0.997, p = 0.039), but not in AF (HR 0.704, 95% CI 0.396-1.253, p = 0.233) after PVI. CONCLUSIONS: Acute termination of induced rhythm is not a reliable ablation endpoint during substrate modification in patients with inducible arrhythmia after PVI.

Quality of Anticoagulation and Treatment Satisfaction in Patients with Non-Valvular Atrial Fibrillation Treated with Vitamin K Antagonist: Result from the KORean Atrial Fibrillation Investigation II.

BACKGROUND: Vitamin K antagonist (VKA) to prevent thromboembolism in non-valvular atrial fibrillation (NVAF) patients has limitations such as drug interaction. This study investigated the clinical characteristics of Korean patients treated with VKA for stroke prevention and assessed quality of VKA therapy and treatment satisfaction. METHODS: We conducted a multicenter, prospective, non-interventional study. Patients with CHADS2 ≥ 1 and treated with VKA (started within the last 3 months) were enrolled from April 2013 to March 2014. Demographic and clinical features including risk factors of stroke and VKA treatment information was collected at baseline. Treatment patterns and international normalized ratio (INR) level were evaluated during follow-up. Time in therapeutic range (TTR) > 60% indicated well-controlled INR. Treatment satisfaction on the VKA use was measured by Treatment Satisfaction Questionnaire for Medication (TSQM) after 3 months of follow-up. RESULTS: A total of 877 patients (age, 67; male, 60%) were enrolled and followed up for one year. More than half of patients (56%) had CHADS2 ≥ 2 and 83.6% had CHA2DS2-VASc ≥ 2. A total of 852 patients had one or more INR measurement during their follow-up period. Among those patients, 25.5% discontinued VKA treatment during follow-up. Of all patients, 626 patients (73%) had poor-controlled INR (TTR < 60%) measure. Patients' treatment satisfaction measured with TSQM was 55.6 in global satisfaction domain. CONCLUSION: INR was poorly controlled in Korean NVAF patients treated with VKA. VKA users also showed low treatment satisfaction.

Super low work function of alkali-metal-adsorbed transition metal dichalcogenides.

Discovering the materials that have work functions less than 1 eV is essential for efficient thermionic energy converter (TEC). The lowest work function of materials reported so far is in a range of about 1 eV. Here, to design low work function materials, we perform first-principles calculations on selected materials of transition metal dichalcogenide as substrates and alkali metals as adsorbates. The work function of our selected materials has a dip ubiquitously independent of the true binding distances of the adsorbates and exhibits contrasting behavior between empty d-shell elements (K, Rb, and Cs) and the others (Li and Na). We show that the interaction of empty d-orbitals of alkali metals and lone pair electrons of chalcogen is a key to the behavior of the work function. From calculated key parameters that determine the work function, we find that, regardless of the amount of charge transfer, K on WTe2 induces the largest surface dipole moment, which consequently makes the surface work function of as small as 0.8 eV, the smallest reported to date, and that the work function is lowered further to 0.7 eV by lattice strains. We demonstrate that the thermal efficiency of TEC using the low work function material exceeds that of thermoelectric materials with figure of merit of 5-10 in temperature range of 880-1200 K.

High coronary calcium score and post-procedural CK-MB are noninvasive predictors of coronary stent restenosis.

PURPOSE: High coronary calcium score (CCS) and post-procedural cardiac enzyme may be related with poor outcomes in patients with coronary stent implantation. METHODS: A total of 1,072 patients (63.2% male, mean age: 61.7±10.3 years) who underwent coronary multi-detect computed tomography at index procedure and follow-up coronary angiography (CAG) after drug-eluting stent (DES) were divided into two groups: those with and without target lesion revascularization (TLR; >50% reduction in luminal stent diameter or angina symptoms on follow-up CAG). The CCSs for predicting stent revascularization were elucidated. RESULTS: There were no significant differences between the two groups with regard to risk factors. The initial CCS was significantly higher in the TLR group (1,102.4±743.7 vs 345.8±51.05, P=0.04). After adjustment of significant factors for TLR, only CCS and post-procedural creatine kinase MB form (CK-MB) elevation were significant predictors of coronary artery TLR. Receiver operation curve revealed that >800 in CCS had 69% in sensitivity and 88% in specificity about predicting the TLR. CONCLUSION: High CCS with post-procedural CK-MB might be the useful predictors for TLR after DES implantation.

Effects of metabolic syndrome on aortic pulse wave velocity.

BACKGROUND: The purpose of this study was to compare the value and evaluate the validity of non-invasive methods for the detection of vascular stiffness in never-treated individuals with metabolic syndrome (MetS). METHODS: A total of 59 subjects (mean age, 60 ± 12 years; male:female = 35:24) were enrolled in the study and were categorized into the positive MetS (MetS[+]: N = 32) and negative group (MetS[-]: N = 27), according to the parameters set by the National Cholesterol Education Program's Adult Treatment Panel III. Pulse wave velocity (PWV) of the aorta, arm, and leg, Framingham risk score (FRS), ankle-brachial index (ABI), and carotid intima-media thickness (IMT) for vascular aging were measured for the two groups. RESULTS: Aortic PWV (PWVaor) was significantly higher in MetS(+) than MetS(-) group (7.0 ± 1.4 m/s vs. 8.4 ± 1.6 m/s, p < 0.01), while ABI was significantly lower in MetS(+) than MetS(-) group (1.2 ± 0.1 vs. 1.1 ± 0.2, p = 0.03), respectively. FRS was significantly higher in MetS(+) than MetS(-) group (11 ± 5 vs. 14 ± 4, p = 0.05). The both mean IMT was higher in MetS(+) than MetS(-) group (right: 0.94 ± 0.20 mm vs. 0.81 ± 0.20 mm, p = 0.03; left: 0.93 ± 0.20 mm vs. 0.79 ± 0.20 mm, p = 0.03, respectively). For predicting the probability of the presence of MetS, PWVaor was an independent tool (p = 0.04; odds ratio, 1.88; 95% confidence interval, 1.03 to 3.42) and a cut-off value of PWVaor of 7.4 m/s showed a sensitivity of 66.7% and a specificity of 47.6%. CONCLUSIONS: We suggest that PWVaor, combined with traditional tools, can play an important role as a complementary or alternative tool for the detection of vascular stiffness in never-treated individuals with MetS.

Variants of Brugada Syndrome and Early Repolarization Syndrome: An Expanded Concept of J-Wave Syndrome.

BACKGROUND: The role of J-waves in the pathogenesis of ventricular fibrillation (VF) occurring in structurally normal hearts is important. METHODS: We evaluated 127 patients who received an implantable cardioverter-defibrillator (ICD) for Brugada syndrome (BS, n = 53), early repolarization syndrome (ERS, n = 24), and patients with unknown or deferred diagnosis (n = 50). Electrocardiography (ECG), clinical characteristics, and ICD data were analyzed. RESULTS: J-waves were found in 27/50 patients with VF of unknown/deferred diagnosis. The J-waves were reminiscent of those seen in BS or ERS, and this subgroup of patients was termed variants of ERS and BS (VEB). In 12 VEB patients, the J/ST/T-wave morphology was coved, although amplitudes were <0.2 mV. In 15 patients, noncoved-type J/ST/T-waves were present in the right precordial leads. In the remaining 23 patients, no J-waves were identified. VEB patients exhibited clinical characteristics similar to those of BS and ERS patients. Phenotypic transition and overlap were observed among patients with BS, ERS, and VEB. Twelve patients with BS had background inferolateral ER, while five ERS patients showed prominent right precordial J-waves. Patients with this transient phenotype overlap showed a significantly lower shock-free survival than the rest of the study patients. CONCLUSIONS: VEB patients demonstrate ECG phenotype similar to but distinct from those of BS and ERS. The spectral nature of J-wave morphology/distribution and phenotypic transition/overlap suggest a common pathophysiologic background in patients with VEB, BS, and ERS. Prognostic implication of these ECG variations requires further investigation.

Differences between Korea and Japan in Physician Decision Making Regarding Permanent Pacemaker Implantation.

BACKGROUND AND OBJECTIVES: The number of permanent pacemakers (PPMs) implanted in patients in Japan and Korea differs significantly. We aimed to investigate the differences in decision making processes of implanting a PPM. MATERIALS AND METHODS: Our survey included 15 clinical case scenarios based on the 2008 AHA/ACC/HRS guidelines for device-based therapy of cardiac rhythm abnormalities (class unspecified). Members of the Korean and Japanese Societies of Cardiology were asked to rate each scenario according to a 5-point scale and to indicate their decisions for or against implantation. RESULTS: Eighty-nine Korean physicians and 192 Japanese physicians replied to the questionnaire. For the case scenarios in which there was a class I indication for PPM implantation, the decision to implant a PPM did not differ significantly between the two physician groups. However, the Japanese physicians were significantly more likely than the Korean physicians to choose implantation in class IIa scenarios (48% vs. 37%, p<0.001), class IIb scenarios (40% vs. 19%, p<0.001), and class III scenarios (36% vs. 18%, p<0.001). These results did not change when the cases were categorized based on disease entity, such as sinus node dysfunction and conduction abnormality. CONCLUSION: Korean physicians are less likely than Japanese physicians to favor a PPM implantation when considering a variety of clinical case scenarios, which probably contributes to the relatively small number of PPMs implanted in patients in Korea as compared with those in Japan.

Restoration of Mitral Inflow Velocity Until Blanking Period Is Associated With Successful Ablation for Persistent Atrial Fibrillation.

Radiofrequency catheter ablation (RFCA) is a useful therapeutic option for atrial fibrillation (AF), although outcomes are less effective for persistent AF. The aim of this study was to elucidate the echocardiographic parameters associated with successful RFCA in patients with persistent AF.A total of 159 patients (mean age, 60.8 ± 9.6 years, 125 males [78.6%]) who underwent RFCA for persistent AF from April 2009 to May 2014 were included, retrospectively. Transthoracic echocardiography was performed at baseline, 3 months, 6 months, and 1 year following RFCA. The subjects were divided into 2 groups, a recurrence group and a non-recurrence group. One hundred eleven of the 159 patients (69.8%) remained free from recurrent atrial tachyarrhythmia during follow-up (mean, 20.6 ± 17.4 months). Peak A wave velocity (38.1 ± 14.1 in the recurrence group; 48.0 ± 20.7 in the non-recurrence group, P = 0.01), peak E wave velocity (76.4 ± 19.1 versus 68.8 ± 19.5, P = 0.03), deceleration time (196.3 ± 54.4 versus 219.9 ± 64.1, P = 0.04), and left atrial (LA) diameter (44.5 ± 7.3 versus 41.0 ± 5.6, P = 0.01) at 3 months after ablation were significantly different between the two groups. Among echocardiographic parameters, peak A wave velocity (OR 0.96, 95% confidence interval [CI] 0.92-0.99) and LA diameter (OR 1.13, 95% CI 1.011.25) were associated with AF recurrence.After RFCA for persistent AF, LA anatomical and functional changes occurred during a 3-month blanking period. Restoration of peak A wave velocity and LA size are associated with successful ablation.

Serum Osteoprotegerin Is Associated With Calcified Carotid Plaque: A Strobe-Compliant Observational Study.

Osteoprotegerin (OPG) is a kind of tumor necrosis factor, which is related to bone metabolism and vascular calcification. The increase of Osteoprotegerin concentration in serum is related to cardiovascular diseases in humans. The purpose of this study was to figure out the relevance between osteoprotegerin in serum and carotid calcification. Serum OPG concentrations were compared in 145 patients who underwent carotid sonography (average age: 68 ±â€Š9 years old, male: female = 81:64). A calcified plaque (CP) (37 people [27%]), a noncalcified plaque (NCP) (54 people [37%]), and a nonplaque (NP) (54 people [37%]) were classified for this study. No significant differences among 3 groups were demonstrated in the distribution of age, diabetes, high blood pressure, and hyperlipidemia. Serum osteoprotegerin concentrations were significantly increased in CP group rather than NCP group or NP group; (median [interquartile range], 4016 [1410] vs 3210 [1802] pg/mL, P < 0.05 and 4016 [1410] vs 3204 [1754] pg/mL, P < 0.05). Serum osteoprotegerin concentrations did not indicate a significant difference between NCP Group or NP Group. This study had proved that patient group accompanied with carotid calcification in carotid artery disease had an increased serum OPG concentration, so it could consider that OPG plays an important function on calcification related to arteriosclerosis.

Achievement of successful pulmonary vein isolation: methods of adenosine testing and incremental benefit of exit block.

PURPOSE: Several approaches were tried to achieve complete pulmonary vein isolation (PVI). The aims of this study were to (1) compare adenosine-induced PV conduction and exit conduction, (2) determine the adequate adenosine dose, and (3) investigate the correlation of dormant conduction and recurrence of atrial fibrillation (AF). METHODS: A total of 378 consecutive patients who underwent PVI from June 2012 to April 2015 were prospectively included (the de novo procedure in 318 (84.1 %) and a redo procedure in 60 (15.9 %)). After the exit block was assessed, 20 mg adenosine was injected into the left atrium. If dormant conduction was observed, 12 and 6 mg of adenosine were injected sequentially. RESULTS: Exit conduction during PV pacing was observed in 34 patients (9 %), and dormant conduction was observed in 92 patients (24.3 %). Among them, 74 (80.4 %, 74/92) demonstrated dormant conduction without exit conduction and 16 (47.1 %, 16/34) showed exit conduction without dormant conduction. The 20-mg dose of adenosine had an additive yield in patients with dormant conduction, compared to that of 12 mg (93 %, 86/92) or 6 mg (80 %, 74/92). There was no significant difference in the recurrence rate regarding dormant conduction. The pattern of prevalence of reconnected origin during the redo procedure was similar to that of dormant conduction during the index procedure. CONCLUSIONS: There was a discrepancy between adenosine-induced PVI and exit block. Therefore, exit block test has additional value to verify latent incomplete PVI in conjunction with adenosine test. Furthermore, high-dose adenosine had an additive yield. CLINICAL TRIAL REGISTRATION: https://www.clinicaltrials.gov/ct2/show/NCT01932112.

Visualization of the Critical Isthmus by Tracking Delayed Potential in Edited Windows for Scar-Related Ventricular Tachycardia.

BACKGROUND AND OBJECTIVES: Identifying the critical isthmus of slow conduction is crucial for successful treatment of scar-related ventricular tachycardia. Current 3D mapping is not designed for tracking the critical isthmus and may lead to a risk of extensive ablation. We edited the algorithm to track the delayed potential in order to visualize the isthmus and compared the edited map with a conventional map. SUBJECTS AND METHODS: We marked every point that showed delayed potential with blue color. After substrate mapping, we edited to reset the annotation from true ventricular potential to delayed potential and then changed the window of interest from the conventional zone (early, 50-60%; late, 40-50% from peak of QRS) to the edited zone (early, 80-90%; late, 10-20%) for every blue point. Finally, we compared the propagation maps before and after editing. RESULTS: We analyzed five scar-related ventricular tachycardia cases. In the propagation maps, the resetting map showed the critical isthmus and entrance and exit sites of tachycardia that showed figure 8 reentry. However, conventional maps only showed the earliest ventricular activation sites and searched for focal tachycardia. All of the tachycardia cases were terminated by ablating the area around the isthmus. CONCLUSION: Identifying the channel and direction of the critical isthmus by a new editing method to track delayed potential is essential in scar-related tachycardia.