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.

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.

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.

Impact of left anterior line on left atrial appendage contractility in patients who underwent catheter ablation for chronic atrial fibrillation.

BACKGROUND: Left anterior line (LAL) has been used as a substitute for mitral isthmus line for catheter ablation of chronic atrial fibrillation (AF). However, it results in left anterolateral conduction delay and might affect left atrial (LA) contractility. We aimed to investigate whether LAL decreases LA appendage function. METHODS: This study included 46 patients (30 men, mean age 58 ± 9 years, group 1) with persistent AF who underwent catheter ablation including LAL. Thirty patients with paroxysmal AF who received no additional LA ablation were compared as control group (21 males, mean age 56 ± 8 years, group 2). Transthoracic and transesophageal echocardiography with Doppler tissue imaging was performed in sinus rhythm before and after the ablation. We compared the following variables: (1) E/A ratio of the mitral flow velocity, (2) ratio of early mitral inflow and mitral septal annulus velocity (E/Em), (3) peak velocity of appendage outflow (ApVmax), and (4) time delay from QRS onset to appendage outflow (TDqa). RESULTS: LA diameter was significantly reduced after ablation in both groups. In group 1, parameters for diastolic function (E/A ratio, 1.7 ± 0.5 vs 2.0 ± 0.6, P = 0.197; E/Em, 11.7 ± 4.8 vs 11.6 ± 5.1, P = 0.883) and appendage flow (ApVmax, 55.2 ± 19.9 cm/s vs 50.3 ± 19.3 cm/s, P = 0.203; TDqa, -77.3 ± 30.1 ms vs -66.1 ± 60.8 ms, P = 0.265) did not change significantly after ablation. Changes of ApVmax and TDqa after ablation were not significantly different between two groups (P = 0.409 and P = 0.195, respectively). CONCLUSIONS: LAL ablation did not aggravate mitral flow pattern or change appendage outflow. LAL could be used without concern over worsening LA diastolic and appendage function.

Circadian and seasonal variations of ventricular tachyarrhythmias in patients with early repolarization syndrome and Brugada syndrome: analysis of patients with implantable cardioverter defibrillator.

INTRODUCTION: The circadian and seasonal patterns of ventricular tachyarrhythmia (VTA) in patients with early repolarization syndrome (ERS) have not been determined. We compared the timing of VTAs in patients with ERS and Brugada syndrome (BS). METHODS AND RESULTS: We enrolled patients with ERS (n = 14) and BS (n = 53) who underwent implantable cardioverter defibrillator (ICD) implantation. The timing of VTAs, including cardiac arrest and appropriate shocks, was determined. During follow up of 6.4 ± 3.6 years in the ERS group and 5.0 ± 3.3 years in the BS group, 5 of 14 (36%) ERS and 10 of 53 (19%) BS patients experienced appropriate shocks (P = 0.37). Cardiac arrest showed a trend of nocturnal distribution peaking from midnight to early morning (P = 0.14 in ERS, P = 0.16 in BS). Circadian distribution of appropriate shocks showed a significant nocturnal peak in patients with ERS (P < 0.0001) but a trend toward a nocturnal peak in patients with BS (P = 0.08). There were no seasonal differences in cardiac arrest in patients with ERS and BS. However, patients with ERS showed a seasonal peak in appropriate shocks from spring to summer (P < 0.0001). There was no significant seasonal peak in patients with BS. The timing of VTAs (cardiac arrest plus appropriate shock) showed significant nocturnal distributions in patients with ERS and BS (P < 0.01, respectively). A significant clustering of VTAs was noted from spring to summer (P < 0.01) in patients with ERS, but not in patients with BS (P = 0.42). CONCLUSIONS: Incidence of VTAs showed marked circadian variations with night-time peaks in patients with ERS and BS.

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.

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.

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.

Uptake of F-18 FDG and ultrasound analysis of carotid plaque.

OBJECTIVES: To elucidate the relation between the echolucent plaque on carotid ultrasound and acute inflammation on F-18 FDG carotid PET/CT. METHODS: Thirty nine patients (M:F ratio = 23:16, mean age = 63 ± 11 years) that underwent coronary angiography and carotid ultrasound were divided into three groups-echolucent plaque (n = 22), calcified (n = 10), and no plaque(n = 7). All the patients underwent F-18 FDG carotid PET/CT. The mean standardized uptake values (SUV), namely target to background ratio (TBR) on 180 minutes delayed F-18 FDG carotid PET/CT images were compared with levels of serum inflammatory markers and lipid profiles, and in terms of the presence of carotid plaque on carotid US. RESULTS: 180 minutes TBR of carotid arterial wall at echolucent plaque, calcified plaque, and no plaque were 1.40 ± 0.05, 1.23 ± 0.03, 1.17 ± 0.03 in both carotid artery. TBR of carotid arterial walls for echolucent plaque were significantly larger than TBR for calcified, and no plaque respectively at the both side of carotid artery (P < .05). Serum HDL levels were found to be inversely correlated with F-18 FDG uptake at both carotid arteries (r = -0.43, P = .005) on 180 minutes delayed phase images. Also serum hs-CRP levels were found to be correlated with F-18 FDG TBR values of right carotid arteries (r = 0.41, P = .04). CONCLUSIONS: Our results show that F-18 FDG carotid PET/CT can depict metabolically active atherosclerotic plaques, and suggest that F-18 FDG carotid PET/CT can be used as a noninvasive imaging modality for functional evaluation of atherosclerosis.

Prevalence of electrocardiographic findings suggestive of sudden cardiac death risk in 10,867 apparently healthy young Korean men.

BACKGROUND: The objective of this study was to determine the prevalence of electrocardiographic (ECG) findings suggestive of sudden cardiac death risk in apparently healthy young Korean men. METHODS: We administered questionnaires that elicited personal and family histories and performed ECGs on 10,867 male subjects (mean age, 20.9 years). The subjects with abnormal ECG findings underwent echocardiography, a treadmill test, Holter monitoring, a flecainide provocation test, or an electrophysiologic study (EPS) according to the ECG findings and histories. RESULTS: Of the subjects, 5.95% had left ventricular hypertrophy on ECG, but no subjects had hypertrophic cardiomyopathy by echocardiography. The percentage of subjects with a Brugada ECG pattern was 0.90%. We identified one subject with a positive result on the flecainide provocation test. The percentage of subjects with a preexcitation ECG was 0.17%. In two of the subjects, supraventricular tachycardia was induced in the EPS. Of the subjects, 0.05% had epsilon waves, but there were no subjects with arrhythmogenic right ventricular dysplasia/cardiomyopathy by echocardiography. The percentage of subjects with long QT intervals was 0.02%, but there were no arrhythmias on the treadmill test or Holter monitoring. CONCLUSIONS: The prevalence of a Brugada ECG pattern in apparently healthy young men is higher in Korea than other countries.

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.

Relationship between resting electrocardiographic parameters and estimated 10-year risk for coronary heart disease in healthy adults in the USA.

BACKGROUND: Little is known about the relationship between resting electrocardiogram (ECG) parameters and the incidence of coronary heart disease (CHD). We sought to establish the association between ECG parameters and estimated 10-year risk for CHD. METHODS: We applied the risk prediction algorithm used by the National Cholesterol Education Program Adult Treatment Panel III guidelines to data from 6399 individuals in the Third National Health and Nutrition Examination Survey (aged 40-79 years) who had sinus rhythm, no previous heart disease, and no evidence of prior myocardial infarction according to the 12-lead Minnesota Code. We used multiple linear and logistic regression models to determine the relationship between 10-year risk for CHD and levels of resting ECG parameters. RESULTS: After adjusting for age, gender, race, and body mass index, individuals with high risk had higher heart rate (HR), left ventricular mass index (LVMI), and cardiac infarction injury score (CIIS), and longer HR-corrected QT (QTc) interval than those with low risk. In models fully adjusted for coronary risk factors, individuals in the highest quintile of HR, PR, and QTc interval were 2.2, 0.7, and 1.8 times, respectively, more likely to have a high 10-year risk as those in the lowest quintiles. There are dose-dependent associations between HR, LVMI, CIIS, and QTc interval and the 10-year risk group. CONCLUSIONS: These findings indicate that high HR, LVMI, and CIIS and prolonged QTc interval are positively and prolonged PR interval is negatively associated with high 10-year risk for CHD in a general population.

The significance of repetitive ventricular responses induced by radiofrequency energy application for idiopathic left ventricular tachycardia.

In radiofrequency (RF) ablation for idiopathic left ventricular tachycardia (ILVT), the termination of tachycardia during RF ablation is considered a hallmark of success. However, in cases of patients with difficulty of induction of ventricular tachycardia (VT), the evaluation of procedural success can be problematic. We have observed thermal responses reflected as ventricular rhythm change to RF energy delivered on sinus rhythm for ILVT. We therefore describe the significance of repetitive ventricular responses. The study subjects were 11 ILVT patients for whom RF energy was delivered during sinus rhythm because of difficulty in re-induction of tachycardia. During each energy delivery, we focused on the occurrence of repetitive ventricular responses especially exhibiting a similar morphology to clinical VT. The repetitive ventricular responses were noted in 10 of 11 patients. Two patients received a second procedure due to the recurrence of ILVT. The mean follow-up period was 36.2+/-12.8 months. The clinical course of the remaining patients was favorable and without recurrence of ILVT. Based on the favorable clinical outcomes, ablation-induced repetitive ventricular responses with similar QRS morphology to clinical ILVT are useful markers for selecting an ablation site and could be used as an additional mapping method, termed as "thermal mapping".

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.

Absorbing-state phase transitions on percolating lattices.

We study nonequilibrium phase transitions of reaction-diffusion systems defined on randomly diluted lattices, focusing on the transition across the lattice percolation threshold. To develop a theory for this transition, we combine classical percolation theory with the properties of the supercritical nonequilibrium system on a finite-size cluster. In the case of the contact process, the interplay between geometric criticality due to percolation and dynamical fluctuations of the nonequilibrium system leads to a different universality class. The critical point is characterized by ultraslow activated dynamical scaling and accompanied by strong Griffiths singularities. To confirm the universality of this exotic scaling scenario we also study the generalized contact process with several (symmetric) absorbing states and we support our theory by extensive Monte Carlo simulations.

Acute changes in cardiac synchrony and output according to RV pacing sites in Koreans with normal cardiac function.

INTRODUCTION: The synchrony of the pacing heart can be affected by the right ventricular (RV) pacing site and is crucial to cardiac function in pacemaker recipients. We evaluated the acute changes in cardiac synchrony according to the RV pacing sites in normal systolic functioning subjects with normal QRS. METHODS: We conducted this study with 30 patients with the pacing in the RV apex (RVA), RV septum (RVS), and RV outflow tract (RVOT) in a sequential manner. Transthoracic echocardiography was conducted at rest and during pacing in order to measure interventricular and intraventricular dyssynchrony in all patients. RESULTS: QRS duration (148.1 +/- 12.8 ms) of RVA pacing was significantly shorter than that of RVS pacing (154.4 +/- 14.1 ms, P < 0.01) and RVOT pacing (160.6 +/- 15.7 ms, P < 0.001). We noted no statistically significant difference in cardiac output according to the pacing sites. The interventricular dyssynchrony with M-mode and Doppler echocardiography in RVOT pacing was increased to an insignificant degree as compared with those with RVS pacing or RVA pacing. The intraventricular dyssynchrony with tissue Doppler echocardiography in RVA pacing was reduced significantly as compared with that of RVS pacing or RVOT (RVA = 60.3 +/- 32.7 ms, RVS = 82.1 +/- 33.8 ms, RVOT = 79.1 +/- 33.3 ms; RVA vs RVS = P < 0.05, RVA vs RVOT = P < 0.01, RVS vs RVOT = P = NS). CONCLUSION: RVA pacing is superior to RVS and RVOT pacing with regard to intraventricular synchrony in normal systolic functioning subjects with normal QRS. Cardiac output at RVA pacing is not inferior to other sites.

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.