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BACKGROUND: Right ventricular (RV) apical pacing may result in ventricular dyssynchrony, which is associated with functional and morphological changes in the left ventricle (LV). Our aim is to assess contraction and hypertrophy-related protein expression changes in the LV after RV apical pacing. METHODS AND RESULTS: Six dogs underwent dual chamber pacemaker (DDD) implantation and atrioventricular nodal catheter ablation. The pacing group received atria-sensed RV apical pacing for 12 weeks. LV dyssynchrony was assessed with speckle tracking technique. Subsequently, hearts were processed for Western blotting. Four sham-operated dogs were included for comparison. After 12 weeks of RV pacing, cardiac chamber size and LV ejection fraction remained unchanged. Both electrical and mechanical dyssynchrony were evident in RV-paced dogs compared with sham-operated dogs. The late-activated LV lateral wall of paced dogs displayed a 23% reduction in the amount of sarcoplasmic reticulum Ca(2+) ATPase, a 32% reduction in phospholamban levels, but a 3.6-fold increase in phospho-JNK expression, a 2.2-fold increase in phospho-p38, and 1.9-fold increase in phospho-ERK expression. There were no significant differences in the early-activated LV septum between paced and sham dogs. CONCLUSIONS: Temporal dispersion of mechanical activation by RV apical pacing induced spatial dispersion of protein expression in the LV. [ABSTRACT FROM AUTHOR]

This long-term study sought to determine the clinical implication of defective sinus node and AV conduction tissue in patients with left atria! isomerism (LAI). From 1984 to 1998, a total of 22 patients were identified as LAI. Patient age at the last follow-up ranged from 2 to 276 months (90 ± 70 months). Associated cardiac anomalies were interruption of the inferior vena cava (n = 18, 82%), common atrium (n = 9, 41%), AV canal (n = 14, 64%), double-outlet right ventricle (n = 6, 36%). and pulmonary stenosis (n = 15. 68%). Palliative interventions were performed in 16 patients [Fontan-type operation in 4 patients, shunt followed by Fontan-type operation in 2, repair of septal defect in 4, and extracardiac intervention in 6). During the follow-up, over half of the patients (n = 14, 64%) developed bradyarrhythmia (onset age: from 1 to 264 months; median 78 months): functional rhythm (n = 11), sinus bradycardia (n = 8) (5 patients also had functional rhythm), and AV block (n =2, both also had functional rhythm). The probability free from bradyarrhythmia was 80% and 46% at the age of 2 and 6 years, respectively. None of the bradyarrhythmias were directly related to open-heart surgery. Besides, functional ectopic tachycardia occurred after Fontan-type operation in three of six patients. In two patients, a Mahaim-like pathway was identified during the electrophysiological study. The patients with LAI had a high probability of developing bradyarrhythmias due to abnormal sinus node function. Varied AV conduction abnormalities may include compromised AV conduction, junctional ectopic tachycardia after Fontan-type operation, and an association of Mahaim-like pathway. [ABSTRACT FROM AUTHOR]

Introduction: The funny current (If) contributes to phase IV spontaneous depolarization in cardiac pacemaker tissue. Enhanced If activity in myocardial tissue may lead to increased automaticity and therefore tachyarrhythmia. We measured the amount of If activity in the messenger ribonucleic acid (mRNA) in human atrial tissue and correlated the mRNA amount to left atrial filling pressure and atrial fibrillation (AF). Methods and Results: A total of 34 patients undergoing open heart surgery were included (15 men and 19 women, aged 55 ± 10 years). Atrial tissue was obtained from the right atrial free wall, the right atrial appendage, the left atrial free wall, and the left atrial appendage, respectively. The mRNA amount of the If channel was measured by reverse transcription polymerase chain reaction and was normalized to the mRNA levels of glyceraldehyde 3-phosphate dehydrogenase. We found that the If channel mRNA was present at ail the atrial sampling sites. A higher left atrial filling pressure, an indicator of congestive bean failure, was associated with a higher If mRNA level (r² = 0.446, P < 0.01 by linear regression). We also found that the mRNA amount was significantly higher in patients with AF than in patients without AF (1.68 ± 0.49 vs 1.27 ± 0.43; P < 0.05). Age, sex, right atrial filling pressure, left atrial dimension, and left ventricular ejection fraction had no significant effect on the mRNA level. conclusion: The mRNA of the If channel is present in the free-wall area and appendage area from both atria. Increased left atrial filling pressure and clinical AF are associated with increased If mRNA level. [ABSTRACT FROM AUTHOR]

Background: Exercise intolerance is a common symptom associated with atrial fibrillation (AF). However, echocardiographic markers that can predict impaired exercise capacity are lacking., Objective: This study aimed to investigate the association between echocardiographic parameters and exercise capacity assessed by cardiopulmonary exercise testing in patients with AF., Methods: This single-center prospective study enrolled patients with AF who underwent echocardiography and cardiopulmonary exercise testing to evaluate exercise capacity at a tertiary center for AF management from 2020 to 2022. Patients with valvular heart disease, reduced left ventricular ejection fraction, or documented cardiomyopathy were excluded., Results: Of the 188 patients, 134 (71.2%) exhibited impaired exercise capacity (peak oxygen consumption ≤85%), including 4 (2.1%) having poor exercise capacity (peak oxygen consumption <50%). Echocardiographic findings revealed that these patients had an enlarged left atrial end-systolic diameter (LA); smaller left ventricular end-diastolic diameter (LVEDD); and increased relative wall thickness, tricuspid regurgitation velocity, and LA/LVEDD and E/e' ratios. In addition, they exhibited lower peak systolic velocity of the mitral annulus and LA reservoir strain. In the multivariate regression model, LA/LVEDD remained the only significant echocardiographic parameter after adjustment for age, sex, and body mass index (P = .020). This significance persisted even after incorporation of heart rate reserve, N-terminal pro-B-type natriuretic peptide level, and beta-blocker use into the model., Conclusion: In patients with AF, LA/LVEDD is strongly associated with exercise capacity. Further follow-up and validation are necessary to clarify its clinical implications in patient care., Competing Interests: Disclosures The authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background and Objectives: This study aimed to assess the utility of Doppler echocardiography in evaluating left ventricular diastolic function, and prognosis in patients with systemic lupus erythematosus (SLE)., Patients and Methods: A total of 286 SLE patients were selected along with 100 age- and gender-matched healthy individuals who underwent physical examinations. Clinical baseline characteristics were collected. Various Doppler echocardiographic parameters were measured and analyzed, including left ventricular posterior wall thickness (LVPWT), interventricular septal diameter (IVSD), left ventricular mass (LVM), LVM index (LVMI), and others., Results: Compared to the control group, SLE patients exhibited significantly higher levels of C-reactive protein and lower levels of complement (C) 3 and C4 ( p < .001). Doppler echocardiographic parameters showed significant differences between SLE patients and healthy controls, including increased LVPWT, IVSD, LVM, LVMI, peak A, PWI + Tei, E/e', TDI-Tei, and decreased e' and E/A ( p < .001). Subgroup analyses indicated more severe ventricular diastolic dysfunction in patients with higher SLE activity and those who experienced cardiovascular events. Correlation analysis revealed positive associations of PWI + Tei, TDI-Tei, and GLS with SLE activity and cardiovascular events ( p < .01). Multivariate logistic regression analysis identified LVMI, PWI + Tei, TDI-Tei, and GLS as significant predictors of cardiovascular events ( p < .05)., Conclusion: Doppler echocardiography is a valuable tool for the early diagnosis of left ventricular diastolic dysfunction in SLE patients. Key echocardiographic parameters, including LVMI, PWI + Tei, TDI-Tei, and GLS, are effective in predicting cardiovascular events, underscoring the importance of comprehensive cardiac function assessments in these patients., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Tendons, which transmit force from muscles to bones, are highly prone to injury. Understanding the mechanisms driving tendon fate would impact efforts to improve tendon healing, yet this knowledge is limited. To find direct regulators of tendon progenitor emergence, we performed a zebrafish high-throughput chemical screen. We established forskolin as a tenogenic inducer across vertebrates, functioning through Creb1a, which is required and sufficient for tendon fate. Putative enhancers containing cyclic AMP (cAMP) response elements (CREs) in humans, mice, and fish drove specific expression in zebrafish cranial and fin tendons. Analysis of these genomic regions identified motifs for early B cell factor (Ebf/EBF) transcription factors. Mutation of CRE or Ebf/EBF motifs significantly disrupted enhancer activity and specificity in tendons. Zebrafish ebf1a/ebf3a mutants displayed defects in tendon formation. Notably, Creb1a/CREB1 and Ebf1a/Ebf3a/EBF1 overexpression facilitated tenogenic induction in zebrafish and human pluripotent stem cells. Together, our work identifies the functional conservation of two transcription factors in promoting tendon fate., Competing Interests: Declaration of interests L.I.Z. is a founder and stockholder of Fate Therapeutics, CAMP4 Therapeutics, Amagma Therapeutics, and Scholar Rock and is a consultant for Celularity., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare and lethal arrhythmia. Ryanodine receptor 2 (RYR2) mutation accounts for ∼60% of CPVT patients which is inherited in an autosomal dominant pattern., Objective: This study aimed to identify CPVT-related mutations and clinical characteristics among Taiwanese CPVT patients and compare to other cohorts worldwide., Methods: Clinical and genetic data were obtained from the Sudden Arrhythmia Death Syndrome Registry in Taiwan (SADS-TW). Forty clinically diagnosed Taiwanese CPVT patients were included., Results: This is the first nationwide CPVT cohort in Taiwan. Among the 29 Taiwanese patients with CPVT-related gene mutations, 55% had RYR2 mutations, a rate similar to other ethnicities. Three out of 12 RYR2 variants were unreported. Exercise-induced symptoms including syncope and cardiac arrest were more frequent in East Asian cohorts (Taiwanese 79%, Japanese 91%), compared to Caucasian cohorts (59%) (p = 0.002)., Conclusion: The discovery of diverse RYR2 mutations in the Taiwanese CVPT population demonstrates the importance of genetic testing in different ethnicities., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Formosan Medical Association. Published by Elsevier B.V. All rights reserved.)

RAS oncogenes (collectively NRAS, HRAS and especially KRAS) are among the most frequently mutated genes in cancer, with common driver mutations occurring at codons 12, 13 and 61 1 . Small molecule inhibitors of the KRAS(G12C) oncoprotein have demonstrated clinical efficacy in patients with multiple cancer types and have led to regulatory approvals for the treatment of non-small cell lung cancer 2,3 . Nevertheless, KRAS G12C mutations account for only around 15% of KRAS-mutated cancers 4,5 , and there are no approved KRAS inhibitors for the majority of patients with tumours containing other common KRAS mutations. Here we describe RMC-7977, a reversible, tri-complex RAS inhibitor with broad-spectrum activity for the active state of both mutant and wild-type KRAS, NRAS and HRAS variants (a RAS(ON) multi-selective inhibitor). Preclinically, RMC-7977 demonstrated potent activity against RAS-addicted tumours carrying various RAS genotypes, particularly against cancer models with KRAS codon 12 mutations (KRAS G12X ). Treatment with RMC-7977 led to tumour regression and was well tolerated in diverse RAS-addicted preclinical cancer models. Additionally, RMC-7977 inhibited the growth of KRAS G12C cancer models that are resistant to KRAS(G12C) inhibitors owing to restoration of RAS pathway signalling. Thus, RAS(ON) multi-selective inhibitors can target multiple oncogenic and wild-type RAS isoforms and have the potential to treat a wide range of RAS-addicted cancers with high unmet clinical need. A related RAS(ON) multi-selective inhibitor, RMC-6236, is currently under clinical evaluation in patients with KRAS-mutant solid tumours (ClinicalTrials.gov identifier: NCT05379985)., (© 2024. The Author(s).)

Background: Obstructive sleep apnea (OSA) is a risk factor for atrial fibrillation (AF); however, it is unclear whether AF increases the risk of OSA. Furthermore, sex differences among patients with both AF and OSA remain unclear. We aimed to determine the association between an increased AF burden and OSA and investigate the differences in clinical characteristics between women and men with AF and OSA., Methods: This was a descriptive, cross-sectional analysis from a prospective cohort study. Patients with non-valvular AF were recruited from the cardiac electrophysiology clinic of a tertiary center; they underwent a home sleep apnea test and 14-day ambulatory electrocardiography. Moderate-to-severe OSA was defined as an apnea-hypopnea index of ≥15., Results: Of 320 patients with AF, 53.4% had moderate-to-severe OSA, and the mean body mass index (BMI) was 25.6 kg/m 2 . Less women (38.2%) had moderate-to-severe OSA than men (59.3%) ( p  < 0.001). In the multivariate analysis, age, being a man, and BMI were significantly associated with moderate-to-severe OSA. AF burden was associated with moderate-to-severe OSA only in men (odds ratio: 1.008; 95% confidence interval: 1.001-1.014). Women and men with OSA had similar BMI ( p  = 0.526) and OSA severity ( p  = 0.754), but women were older than men (70.1 ± 1.3 vs. 63.1 ± 0.9 years, p  < 0.001). Women with moderate-to-severe OSA had a lower AF burden than men did (27.6 ± 7.1 vs. 49.5 ± 3.9%, p  = 0.009)., Conclusions: AF burden is a sex-specific risk factor for OSA and is limited to men. In contrast, women with both AF and OSA have a lower AF burden than men, despite being older and having similar OSA severity and body habitus. Thus, AF may develop later in women with OSA than in men., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Objective: Congenital hyperinsulinism (CHI) is a group of clinically and genetically heterogeneous disorders characterized by dysregulated insulin secretion. The aim of the study was to elucidate genetic etiologies of Taiwanese children with the most severe diazoxide-unresponsive CHI and analyze their genotype-phenotype correlations., Methods: We combined Sanger with whole exome sequencing (WES) to analyze CHI-related genes. The allele frequency of the most common variant was estimated by single-nucleotide polymorphism haplotype analysis. The functional effects of the ATP-sensitive potassium (K ATP ) channel variants were assessed using patch clamp recording and Western blot., Results: Nine of 13 (69%) patients with ten different pathogenic variants (7 in ABCC8 , 2 in KCNJ11 and 1 in GCK ) were identified by the combined sequencing. The variant ABCC8 p.T1042QfsX75 identified in three probands was located in a specific haplotype. Functional study revealed the human SUR1 (hSUR1)-L366F K ATP channels failed to respond to intracellular MgADP and diazoxide while hSUR1-R797Q and hSUR1-R1393C K ATP channels were defective in trafficking. One patient had a de novo dominant mutation in the GCK gene (p.I211F), and WES revealed mosaicism of this variant from another patient., Conclusion: Pathogenic variants in K ATP channels are the most common underlying cause of diazoxide-unresponsive CHI in the Taiwanese cohort. The p.T1042QfsX75 variant in the ABCC8 gene is highly suggestive of a founder effect. The I211F mutation in the GCK gene and three rare SUR1 variants associated with defective gating (p.L366F) or traffic (p.R797Q and p.R1393C) K ATP channels are also associated with the diazoxide-unresponsive phenotype., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Lee, Tsai, Chang, Chen, Fann, Chang, Liu, Wu, Chiu, Hsu, Yang, Lai, Tsai, Yang and Chen.)

Background: Accumulating evidence has demonstrated an association between clinical atrial fibrillation (AF) and cognitive impairment. This study aimed to further clarify the impact of AF burden on cognitive function based on detailed electrophysiological recordings and standardized assessments of cognitive function., Methods: This prospective cohort study, conducted at the Cardiac Electrophysiology Clinic of a tertiary center, included patients with non-valvular AF. AF burden was evaluated using 14-day patch-based electrocardiography. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA)., Results: Enrolled patients (n = 253) were grouped according to the median AF burden (13.52%). Patients with higher AF burden were significantly older and had larger left atrium size, a worse ejection fraction, and a lower MoCA score than those with lower AF burden. Predictors of MoCA score included age, CHA 2 DS 2 -VASc score, AF burden, and Center for Epidemiologic Studies Depression Scale scores. The association between MoCA scores and AF burden remained significant after adjustment for demographic characteristics, underlying diseases, and echocardiographic parameters (standardized beta coefficient: -0.159, 95% confidence interval: -0.020 to -0.004, p = 0.004)., Conclusion: AF burden is associated with cognitive function in patients with AF. Further studies are required to determine whether reducing AF burden can preserve cognitive function in these patients., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: To explore whether modified Chevron osteotomy together with distal soft tissue release would correct moderate to severe HV deformity and what is the minimal clinical important difference (MCID) for objective and subjective evaluating parameters., Methods: From March 2018 to January 2019, 40 hallux valgus patients (including moderate to severe) were enrolled in this retrospective study. The cohort included four males and 36 females. The average age at surgery was 50.95 (range 22-75) years. All patients underwent modified Chevron osteotomy together with distal soft tissue release and completed at least one follow-up at clinic. The American Orthopaedic Foot and Ankle forefoot score (AOFAS, forefoot), Visual Analog Scale (VAS), and Foot Function Index (FFI) were all collected before and after surgery. Besides, the hallux valgus angle (HVA), 1st-2nd intermetatarsal angle (IMA) and distal metatarsal articular angle (DMAA) were measured both before surgery and at last follow-up. All MCID values were calculated by employing distribution-based method., Results: Thirty-seven patients (92.5%) showed satisfied result at a mean 14.3-month follow-up (range 13-22 month). Two patients complained about residual pain at the bunion, and overcorrection (hallux varus) occurred in one patient. Meanwhile, no patient observed nonunion. Being female, age more than 60, residual HVA deformity (>15°), and post IMA more than 9° showed no statistical relationship with the post-operation residual pain (P > 0.05). However, high VAS score before surgery (more than 7) showed strong correlation with residual pain (P < 0.01). The subjective MCID value was 9.50 for AOFAS, 18.92 for FFI, and 1.27 for VAS, respectively., Conclusion: The modified Chevron osteotomy together with distal soft tissue release could achieve a satisfied result for moderate to severe HV deformity at early follow-up. The residual pain was associated with severe pain before surgery (VAS more than 7)., (© 2022 The Authors. Orthopaedic Surgery published by Tianjin Hospital and John Wiley & Sons Australia, Ltd.)

RAF inhibitors unexpectedly induce ERK signaling in normal and tumor cells with elevated RAS activity. Paradoxical activation is believed to be RAS dependent. In this study, we showed that LY3009120, a pan-RAF inhibitor, can unexpectedly cause paradoxical ERK activation in KRAS G12C -dependent lung cancer cell lines, when KRAS is inhibited by ARS1620, a KRAS G12C inhibitor. Using H/N/KRAS-less mouse embryonic fibroblasts, we discovered that classical RAS proteins are not essential for RAF inhibitor-induced paradoxical ERK signaling. In their absence, RAF inhibitors can induce ERK phosphorylation, ERK target gene transcription, and cell proliferation. We further showed that the MRAS/SHOC2 complex is required for this process. This study highlights the complexity of the allosteric RAF regulation by RAF inhibitors, and the importance of other RAS-related proteins in this process., Competing Interests: Competing interest statement: F.M. is a consultant for the following companies: Amgen; Daiichi Ltd., Frontiers Med, Exuma Biotech, Ideaya Biosciences, Kura Oncology, Leidos Biomedical Research, Inc., PellePharm, Pfizer Inc., PMV Pharma and Quanta Therapeutics. F.M. is a consultant for and cofounder of the following companies (with ownership interest including stock options): BridgeBio; DNAtrix Inc., Olema Pharmaceuticals, Inc., and Quartz. F.M. is the scientific director of the National Cancer Institute RAS Initiative at the Frederick National Laboratory for Cancer Research/Leidos Biomedical Research, Inc. F.M. has been a recipient of research grants from Daiichi Sankyo and Gilead Sciences and has a current grant from Boehringer-Ingelheim., (Copyright © 2022 the Author(s). Published by PNAS.)

There has been no long-term clinical follow-up data of survivors or victims of sudden cardiac death (SCD). The Taiwan multi-center sudden arrhythmia death syndrome follow-up and clinical study (TFS-SADS) is a collaborative multi-center study with median follow-up time 43 months. In this cohort, the clinical characteristics of these SADS patients were compared with those with ischemic heart disease (IHD). In this SCD cohort, around half (42%) were patients with IHD, which was different from Caucasian SCD cohorts. Among those with normal heart, most had Brugada syndrome (BrS). Compared to those with SADS, patients with IHD were older, more males and more comorbidities, more arrhythmic death, and lower left ventricular ejection fraction. In the long-term follow-up, patients with SADS had a better survival than those with IHD (p < 0.001). In the Cox regression analysis to identify the independent predictors of mortality, older age, lower LVEF, prior myocardial infarction and history of out-of-hospital cardiac arrest were associated with higher mortality and beta blocker use and idiopathic ventricular fibrillation or tachycardia (IVF/IVT) with a better survival during follow-up. History of prior MI was associated with more arrhythmic death. Several distinct features of SCD were found in the Asia-Pacific region, such as higher proportion of SADS, poorer prognosis of LQTS and better prognosis of IVF/IVT. Patients with SADS had a better survival than those with IHD. For those with SADS, patients with channelopathy had a better survival than those with cardiomyopathy., (© 2021. The Author(s).)

Patients with heart failure and preserved ejection fraction (HFpEF) are known to have reduced systolic myocardial velocity (Sm) with impaired accommodation to exercise. We tested the impact of an aldosterone antagonist on Sm at rest and post-exercise. Forty-nine HFpEF patients (65 ± 11 years, 24 male) with HF signs/symptoms, mitral E/Ea (annular early diastolic velocity) > 8, and left ventricular (LV) EF > 50% were randomized to spironolactone (25 mg/day, 25 patients) or the Control. At baseline and 6 months, we analyzed Sm of basal LV segments at rest and after a 6 min treadmill exercise. At 6 months, post-exercise mean Sm in the spironolactone group became greater than that in the Control (9.2 ± 1.6 vs. 8.3 ± 1.0 cm/s, p = 0.021), mainly due to the increment of post-exercise % increase of lateral Sm (44 ± 30 vs. 30 ± 19% at baseline, p = 0.045). Further analyses showed the presence of systolic dyssynchrony (standard deviation of electromechanical delay of 6-basal LV segments > 35 ms) was independently associated with a poorer response to spironolactone, defined as a post-exercise % increase of lateral Sm < 50% (OR = 2.7, 95% CI = 1.8-4.2) and the increment of Ea < 1.5 cm/s (OR = 1.5, 95% CI = 1.1-2.3). Spironolactone could improve exercise accommodation of regional systolic myocardial velocity for HFpEF patients. However, its benefits could be decreased in those with ventricular dyssynchrony. This suggested possible therapeutic impacts from underlying heterogeneity within HFpEF patients.

Oncogenic forms of KRAS proteins are known to be drivers of pancreatic, colorectal, and lung cancers. The goal of this study is to identify chemical leads that inhibit oncogenic KRAS signaling. We first developed an isogenic panel of mouse embryonic fibroblast (MEF) cell lines that carry wild-type RAS, oncogenic KRAS, and oncogenic BRAF. We validated these cell lines by screening against a tool compound library of 1402 annotated inhibitors in an adenosine triphosphate (ATP)-based cell viability assay. Subsequently, this MEF panel was used to conduct a high-throughput phenotypic screen in a cell viability assay with a proprietary compound library. All 126 compounds that exhibited a selective activity against mutant KRAS were selected and prioritized based on their activities in secondary assays. Finally, five chemical clusters were chosen. They had specific activity against SW620 and LS513 over Colo320 colorectal cancer cell lines. In addition, they had no effects on BRAF V600E , MEK1, extracellular signal-regulated kinase 2 (ERK2), phosphoinositide 3-kinase alpha (PI3Kα), AKT1, or mammalian target of rapamycin (mTOR) as tested in in vitro enzymatic activity assays. Biophysical assays demonstrated that these compounds did not bind directly to KRAS. We further identified the mechanism of action and showed that three of them have CDK9 inhibitory activity. In conclusion, we have developed and validated an isogenic MEF panel that was used successfully to identify RAS oncogenic or wild-type allele-specific vulnerabilities. Furthermore, we identified sensitivity of oncogenic KRAS-expressing cells to CDK9 inhibitors, which warrants future studies of treating KRAS-driven cancers with CDK9 inhibitors.

Background: Left atrial (LA) size represents atrial fibrillation (AF) burden and has been shown to be a predictor for AF stroke. The CHA 2 DS 2 -VASc score is also a well-established predictor of AF stroke. It is unknown to cardiologists whether these two risk scores are correlated, whether both are independent prognostic predictors and complimentary to each other, or whether one of them is a major determinant of stroke risk for AF patients. Method: A total of 708 patients from the National Taiwan University Atrial Fibrillation Registry were longitudinally followed up for more than 15 years. Left atrial size was measured by M mode of echocardiography. Adverse thromboembolic endpoints during follow-up were defined as ischemic stroke or transient ischemic attack. Results: The mean age was 72.1 ± 12.9 years, with 53% men. Both LA size and CHA 2 DS 2 -VASc score were associated with the risk of stroke in univariate analyses. There was a weak but significant positive correlation between LA size and CHA 2 DS 2 -VASc score ( r = 0.17, P < 0.0001). Patients with higher CHA 2 DS 2 -VASc scores had a higher mean LA size ( P < 0.01 for trend). When combining LA size and CHA 2 DS 2 -VASc score in the multivariable Cox model, only CHA 2 DS 2 -VASc score remained statistically significant [HR 1.39 (1.20-1.63); P < 0.001]. Conclusion: LA size is not an independent predictor of AF stroke, and calculation of CHA 2 DS 2 -VASc score may be an alternative to measurement of echocardiographic LA size when evaluating the risk of stroke for AF patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Tsai, Huang, Chen, Chang, Chiu, Lin, Lai, Hwang and Tsai.)

Background/purpose: Malignant hyperthermia (MH) is a life-threatening pharmacogenetic disease with only two known causative genes, RYR1 and CACNA1S. Both are huge genes containing numerous exons, and they reportedly only account for 50-70% of known MH patients. Next-generation sequencing (NGS) technology and bioinformatics could help delineate the genetic diagnosis of MH and several MH-like clinical presentations., Methods: We established a capture-based targeted NGS sequencing framework to examine the whole genomic regions of RYR1, CACNA1S and the 16.6 Kb mitochondrial genome, as well as 12 other genes related to excitation-contraction coupling and/or skeletal muscle calcium homeostasis. We applied bioinformatics analyses to the variants identified in this study and also to the 48 documented RYR1 pathogenic variants., Results: The causative variants were identified in seven of the eight (87.5%) MH families, but in none of the 10 individuals classified as either normal controls (N = 2) or patients displaying MH-like clinical features later found to be caused by other etiologies (N = 8). We showed that RYR1 c.1565A>G (p.Tyr522Cys)(rs118192162) could be a genetic hot spot in the Taiwanese population. Bioinformatics analyses demonstrated low population frequencies and predicted damaging effects from all known pathogenic RYR1 variants. We estimated that more than one in 1149 individuals worldwide carry MH pathogenic variants at RYR1., Conclusion: NGS and bioinformatics are sensitive and specific tools to examine RYR1 and CACNA1S for the genetic diagnosis of MH. Pathogenic variants in RYR1 can be found in the majority of MH patients in Taiwan., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest relevant to this article., (Copyright © 2020. Published by Elsevier B.V.)

Aims: Hypertrophic cardiomyopathy (HCM) is an inheritable disease that leads to sudden cardiac death and heart failure (HF). Sarcomere mutations (SMs) have been associated with HF. However, the differences in ventricular function between SM-positive and SM-negative HCM patients are poorly characterized., Methods and Results: Of the prospectively enrolled 374 unrelated HCM patients in Taiwan, 115 patients underwent both 91 cardiomyopathy-related gene screening and cardiovascular magnetic resonance (45.6 ± 10.6 years old, 76.5% were male). Forty pathogenic/likely pathogenic mutations were identified in 52 patients by next-generation sequencing. The SM-positive group were younger at first cardiovascular event (P = 0.04) and progression to diastolic HF (P = 0.02) with higher N-terminal pro-brain natriuretic peptide (NT-proBNP) [New York Heart Association (NYHA) Class III/IV symptoms with left ventricular ejection fraction > 55%] than the SM-negative group (P < 0.001). SM-positive patients had a greater extent of late gadolinium enhancement (P = 0.01), larger left atrial diameter (P = 0.03), higher normalized peak filling rate (PFR) and PFR ratio, and a greater reduction in global longitudinal strain than SM-negative patients (all P ≤ 0.01). During mean lifelong follow-up time (49.2 ± 15.6 years), SM-positive was a predictor of earlier HF (NYHA Class III/IV symptoms) after multivariate adjustment (hazard ratio 3.5; 95% confidence interval 1.3-9.7; P = 0.015)., Conclusion: SM-positive HCM patients had a higher extent of myocardial fibrosis and more severe ventricular diastolic dysfunction than those without, which may contribute to earlier onset of advanced HF, suggesting the importance of close surveillance and early treatment throughout life., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Background: Compassion fatigue, unprofessional behavior, and burnout are prompting educators to examine medical students' affective reactions to workplace experiences. Attributes of both students and learning environments are influenced by their socio-cultural backgrounds. To prevent 'educational cultural hegemony', opinion leaders have advocated research in under-represented cultural contexts, of which Asia is a prime example. This study aimed to broaden the discourse of medical education by answering the question: how do students react affectively to workplace experiences in a Chinese cultural context?, Methods: In 2014, the authors recruited five female and seven male Taiwanese clerkship students to make 1-2 audio-diary recordings per week for 12 weeks describing affective experiences, to which they had consciously reacted. The authors analyzed transcripts of these recordings thematically in the original Mandarin and prepared a thick description of their findings, including illustrative extracts. An English-speaking education researcher helped them translate this into English, constantly comparing the interpretation with the original, untranslated data., Results: (Mis) matches between their visions of future professional life and clerkship experiences influenced participants' affective reactions, thoughts, and behaviors. Participants managed these reactions by drawing on a range of personal and social resources, which influenced the valence, strength, and nature of their reactions. This complex set of interrelationships was influenced by culturally determined values and norms, of which this report provides a thick description., Conclusion: To avoid educational cultural hegemony, educators need to understand professional behavior in terms of complex interactions between culturally-specific attributes of individual students and learning environments., Trial Registration: The ethics committee of the National Taiwan University (NTU) Hospital gave research ethics approval ( 20130864RINB ).

Background: Brugada syndrome (BrS) is an oligogenic arrhythmic disease with increased risk of sudden cardiac arrest. Several BrS or ECG traits-related single-nucleotide polymorphisms (SNPs) were identified through previous genome-wide association studies in white patients. We aimed to validate these SNPs in BrS patients in the Taiwanese population, assessing the cumulative effect of risk alleles and the BrS-polygenic risk score in predicting cardiac events., Methods: We genotyped 190 unrelated BrS patients using the TWB Array, and Taiwan Biobank was used as controls. SNPs not included in the array were imputed by IMPUTE2. Cox proportional hazards model was used to evaluate the associations between each particular SNP, the collective BrS-polygenic risk score, and clinical outcomes., Results: Of the 88 previously reported SNPs, 22 were validated in Taiwanese BrS patients ( P <0.05). Of the 22 SNPs, 2 (rs10428132 and rs9388451) were linked with susceptibility to BrS, 10 were SNPs previously reaching genome-wide significance, and 10 were SNPs associated with ECG traits. For the 3 most commonly reported SNPs, disease risk increased consistently with the number of risk alleles (odds ratio, 3.54; P trend =1.38×10 -9 for 5 risk alleles versus 1). Similar patterns were observed in both SCN5A mutation+ (odds ratio, 3.66; P trend =0.049) and SCN5A mutation- (odds ratio, 3.75; P trend =8.54×10 -9 ) subgroups. Furthermore, BrS patients without SCN5A mutations had more risk alleles than BrS patients with SCN5A mutations regardless of the range of polygenic risk scores. Three SNPs (rs4687718, rs7784776, and rs2968863) showed significant associations with the composite outcome (sudden cardiac arrest plus syncope, hazard ratio, 2.13, 1.48, and 0.41; P =0.02, 0.006, and 0.008, respectively)., Conclusions: Our findings suggested that some SNPs associated with BrS or ECG traits exist across multiple populations. The cumulative risk of the BrS-related SNPs is similar to that in white BrS patients, but it appears to correlate with the absence of SCN5A mutations.

Background: Brugada syndrome (BrS) is a rare inherited disease causing sudden cardiac death (SCD). Copy number variants (CNVs) can contribute to disease susceptibility, but their role in Brugada syndrome (BrS) is unknown. We aimed to identify a CNV associated with BrS and elucidated its clinical implications., Methods: We enrolled 335 unrelated BrS patients from 2000 to 2018 in the Taiwanese population. Microarray and exome sequencing were used for discovery phase whereas Sanger sequencing was used for the validation phase. HEK cells and zebrafish were used to characterize the function of the CNV variant., Findings: A copy number deletion of GSTM3 (chr1:109737011-109737301, hg38) containing the eighth exon and the transcription stop codon was observed in 23.9% of BrS patients versus 0.8% of 15,829 controls in Taiwan Biobank (P < 0.001), and 0% in gnomAD. Co-segregation analysis showed that the co-segregation rate was 20%. Patch clamp experiments showed that in an oxidative stress environment, GSTM3 down-regulation leads to a significant decrease of cardiac sodium channel current amplitude. Ventricular arrhythmia incidence was significantly greater in gstm3 knockout zebrafish at baseline and after flecainide, but was reduced after quinidine, consistent with clinical observations. BrS patients carrying the GSTM3 deletion had higher rates of sudden cardiac arrest and syncope compared to those without (OR: 3.18 (1.77-5.74), P<0.001; OR: 1.76 (1.02-3.05), P = 0.04, respectively)., Interpretation: This GSTM3 deletion is frequently observed in BrS patients and is associated with reduced I Na , pointing to this as a novel potential genetic modifier/risk predictor for the development of the electrocardiographic and arrhythmic manifestations of BrS., Funding: This work was supported by the Ministry of Science and Technology (107-2314-B-002-261-MY3 to J.M.J. Juang), and by grants HL47678, HL138103 and HL152201 from the National Institutes of Health to CA., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Statins are potent lipid-lowering drugs. Large prospective clinical trials have shown the anti-thrombotic effect of statins, e.g., preventing deep vein thrombosis. However, the mechanism underlying the beneficial effect of statins in reducing thrombus formation remains to be established. We, thus, conduct this study to investigate the potential molecular mechanisms. The cultured human hepatoma cells (HepG2) were used as the in vitro model. The human protein C gene promoter was cloned into the luciferase reporter to study the transcriptional regulation of human protein C gene. Wistar rats fed with simvastatin (5 mg/kg day) were used as the in vivo model. We found that simvastatin increased the expression of protein C in hepatocytes (361 ± 64% and 313 ± 59% after 2 h and 6 h of stimulation, respectively, both p < 0.01). In the animal study, the serum protein C levels were increased in the simvastatin-treated group (7 ± 2.2 unit/ml vs 23.4 ± 19.3 unit/ml and 23.4 ± 18.2 unit/ml and 1 and 2 weeks of treatment, respectively, both p < 0.05). Regarding the possible molecular mechanism, we found that the level of hepatocyte nuclear factor 1α (HNF1α) was also increased in both the in vivo and in vitro models. We found that the protein C promoter activity was increased by simvastatin, and this effect was inhibited by HNF1α knockdown and constitutively active Rac1. Therefore, stains may modulate protein C expression through small GTPase Rac 1 and HNF1α.

Background: Brugada syndrome (BrS) is a heritable sudden cardiac death (SCD) disease with male predominance. Information on gender difference of BrS remains scarce., Aim: To investigate the gender difference of BrS in Han Chinese., Design: We consecutively enrolled 169 BrS patients (153 males and 16 females) from Han Chinese in Taiwan from 1998 to 2017., Methods: Clinical characteristics, electrocardiographic parameters and SCN5A mutation status were compared between genders., Results: The percentage of family history of SCD in females was slightly higher (31.3% vs. 15%, P = 0.15). Females exhibited longer QTc (457.8 ± 33.0 vs. 429.5 ± 42.1 ms, P < 0.01). Regarding cumulative event occurrence by age, Mantel-Cox test showed females had earlier age of onset of first cardiac events (SCD or syncope) than males (P = 0.049), which was mainly attributed to syncope (P < 0.01). Males with SCD exhibited longer QRS duration (114.2 ± 26.8 vs. 104.8 ± 15.3 ms, P = 0.02) and QTc (442.5 ± 57.4 vs. 422.9 ± 28.8 ms, P = 0.02). Males with syncope exhibited longer PR interval (181.2 ± 33.7 vs. 165.7 ± 27.1 ms, P = 0.01), whereas females with SCD or syncope had a trend towards slower heart rates (69.1 ± 9.6 vs. 82.2 ± 16.3 bpm, P = 0.10) than female with no or mild symptoms. There was no difference in the percentage of SCN5A mutation between genders., Conclusion: Gender difference is present in BrS. Females have longer QTc and suffer from syncope earlier than males. Risk of SCD in males is associated with boarder QRS complex and longer QTc, whereas risk of syncope is associated with longer PR interval in males and slower heart rate in females., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: To analysis clinical effects of open reduction and internal fixation in treating Gustilo type I and II patients with open distal humeral fracture., Methods: From 2013 May to 2017 June, 24 patient with Gustilo grade I and II open distal humeral fractures were treated with open reduction and internal fixation, including 20 males and 4 females, aged from 14 to 65 years old with an average of (41.3±13.1) years old. According to Gustilo classification, 16 patients were type I, 8 patients were typeII. Range of motion, complications and secondary surgery were recorded; elbow function were evaluated with VAS (visual analogue scale), MEPS (Mayo elbow performance score) and QuickDASH (quick disabilities of the arm, shoulder, and hand) at 12 months after operation., Results: All patients were followed up from 15 to 60 years with an average of (34.1±11.9) months. VAS score was 0(0, 2); flexion and extension ranged from 50 °to 145° with an average of (115.2±26.1)°; the range of rotation ranged from 100° to 160° with an average of (147.7±17.0)°. MEPS score was for 75 to 90 (90.0±9.1), and 14 patients got excellent result, 10 patients moderate. Quick DASH score was 4.6(0, 14.8). There were 22 patients occurred complications, such as ulnar nerve symptom and internal fixation irritation, and 10 patients accepted the second operation., Conclusions: Open reduction and internal fixation is a safe and efficient method in treating Gustilo type I and II patients with open distal humeral fractures, which has an advantages of good range of movement and function score., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© 2019 by the China Journal of Orthopaedics and Traumatology Press.)

Brugada syndrome (BrS) is a heritable disease that results in sudden cardiac death. In the exome/genomic era, certain reported pathogenic variants in some genetic diseases have been reclassified as benign owing to their high frequency in some ancestries. In the present study, we comprehensively reassessed all previously reported pathogenic variants of BrS. We collected all pathogenic variants of BrS reported in the Human Gene Mutation Database and ClinVar throughout April 2017. We compared the minor allele frequency (MAF) of each variant among different ancestries by searching public whole-genome and exome databases. After considering the maximum credible allele frequency, variants with a MAF ≥ 0.001 were considered to be of questionable pathogenicity. We also investigated the percentage of SCN5A variants with a MAF ≥ 0.001 in 124 BrS patients from the Han Chinese population. We collected a total of 440 BrS variants, of which 18 had a MAF ≥ 0.001. There was a greater percentage of non-SCN5A variants with a MAF ≥ 0.001 than of SCN5A variants (21.8 versus 1.6%, p < 0.0001). There were fewer frameshift and nonsense mutations than missense mutations (0.9 versus 5.6%, p = 0.032). Of the 18 variants, 14 (77.8%) were present only in the reference Asian population. In our cohort, we identified two SCN5A variants (p.A226V and p.V1340I) with MAFs ≥ 0.001 (0.45%). In conclusion, ancestral differences are important when considering the pathogenicity of BrS variants, especially in the case of missense variants and non- SCN5A variants, which may be pathogenic in some ancestries but only disease-predisposing in others.

Background: In treatment of ankle fracture, intraoperative stress tests are used to assess the syndesmotic injury and instability. However, the optimized timing of the strees test should be applied whether in pre- or post-bony fixation during operation is seldom be reported in previous studies. The different strategies on stress test timing would exhibit opposite results within a type of pronation-external rotation (PER) fractures with supracollicular medial malleolar (SMM) fractures. This study was designed to assess the 3-year functional outcomes of the special PER fractures with or without a syndesmotic transfixation based on the results of two different intraoperative stress test strategies., Methods: This retrospective cohort study included 61 PER injury-Weber C ankle fractures combined with SMM fractures who were treated in Beijing Jishuitan Hospital between 2013 and 2014 and followed up for 3 years. Stress test was performed twice intraoperatively. A positive intraoperative stress test before bony fixation and a negative intraoperative stress test after bony fixation were found in these included patients. Twenty-nine patients (Group 1) were treated without a supplemental syndesmotic screw fixation, according to the negative intraoperative stress test after bony fixation, while 32 patients (Group 2) were treated with an additional syndesmotic screw fixation based on the positive intraoperative stress test before bony fixation. The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale and Visual Analog Scale (VAS) for pain scores were the main measurements of outcome. The statistical index of demographic data, fracture morphologic data, time interval of follow-up, AOFAS and VAS were recorded and assessed by SPSS 21.0 software through Fisher exact tests and one-way analysis of variance. The associations between the main outcomes and influential factors were evaluated by linear regression models., Results: We observed no difference in the distribution of age, sex, presence of associated posterior malleolus (PM), fracture dislocation, and fixation of associated PM between two treatment groups. With the numbers available, no statistically significant association could be detected with regard to the AOFAS (Group 1 vs. Group 2, 96.72 ± 6.20 vs. 94.63 ± 8.26, F = 1.24, P = 0.27) and VAS (Group 1 vs. Group 2, 1.47 ± 2.14 vs. 0.72 ± 1.49, F = 2.44, P = 0.12) in association with two strategies., Conclusions: The present study indicates no difference to the use of the syndesmotic screw in terms of the functional outcome between syndesmosis transfixation and no-fixation patients among PER-Weber C ankle fracture patients with SMM fracture after 3-year follow-up. More attention should be paid to pre- and post-bony-fixation intraoperative stress tests and the morphology of medial malleoli fractures in ankle fractures., Competing Interests: There are no conflicts of interest

Acute post-operative pain can remain untreated if patients cannot express themselves. The perfusion index (PI) may decrease when pain activates sympathetic tone and may increase after analgesics are administered. We evaluated if the perfusion index is a feasible indicator for objectively assessing pain relief in the postanesthesia care unit (PACU) and calculated the changes in PI measurements at the time of discharge from the PACU relative to baseline PI measurements to examine if the PI is a useful criterion for discharging patients from the postanesthesia care unit. This retrospective observational study enrolled female patients who were admitted for gynecological or general surgery. The patients received general anesthesia and were admitted to the postanesthesia care unit. The PI, visual analogue scale (VAS) score, heart rate, and blood pressure were recorded before and after administration of intravenous morphine. Changes in these parameters before and after analgesics were administered and the difference of these parameters between age and BMI subgroups were compared. The correlation between the PI and VAS score, ΔPI and ΔVAS, and %ΔPI and %ΔVAS were also evaluated. The percentage change in ΔPI (P9-T0/T0) of the patients at the time of discharge from the postanesthesia care unit relative to baseline PI measurements was calculated. Eighty patients were enrolled, and there were 123 instances during which analgesia was required. Heart rate, PI, and VAS score were significantly different before and after analgesics were administered (p < 0.0001). The difference of parameters between age and BMI subgroups were not significant. The correlation between the PI and VAS score, ΔPI and ΔVAS, and the percentage change in ΔPI and ΔVAS showed weak correlations in age, BMI subgroups, and all measurements. The baseline PI and the PI when arriving at and when being discharged from the postanesthesia care unit were significantly different (p < 0.01). The mean percentage change in Δ PI at the time of discharge from the PACU was 66.2%, and the 99% confidence interval was 12.2%~120.3%. The perfusion index was increased, and the VAS score was decreased significantly after analgesics were administered, but the correlation was weak in each subgroup. The VAS score is a subjective and psychometric parameter. The PI increased when partial pain relief was achieved after morphine was administered but did not reflect pain intensity or changes in the VAS score regardless of age or BMI. A percentage change in ΔPI at the time of discharge from the PACU relative to baseline PI measurements of greater than 12% can be used as a supplemental objective discharge criterion for pain assessment in the postanesthesia care unit.

Introduction: Identifying Brugada electrocardiographic pattern (BrP) early is crucial to prevent sudden cardiac death. Two different diagnostic criteria proposed by International Society for Holter and Noninvasive Electrocardiography (ISHNE) and Heart Rhythm Society/European Heart Rhythm Association/Asia-Pacific Heart Rhythm Society (HRS/EHRA/APHRS) were widely used in clinical practice. The difference in prevalence and prognosis of BrP by applying the two different criteria was never studied before., Methods: This study was prospectively conducted in a nationwide large-scale stratified random sampling community-based cohort (HALST) from Han Chinese population in Taiwan from December 2008 to December 2012. We compared the prevalence and prognosis of BrP defined by the two diagnostic criteria., Results: A total of 5214 adults were enrolled (2530 men) with mean age of 69.3 years. Four had spontaneous type 1 BrP (0.077%). By the HRS/EHRA/APHRS criteria, 68 individuals have type 2 BrP (1.30%) and 101 have type 3 BrP (1.94%) whereas by the ISHNE criteria, 46 individuals exhibited type 2 BrP (0.88%). When applying the ISHNE criteria, the number of individuals with BrP decreased by 71%. However, all-cause mortality and cardiovascular mortality were not different between individuals with or without BrP, irrespective of the criteria used., Conclusions: The two different criteria may impact the diagnostic yield of individuals with BrP, but do not affect the prognosis of the individuals with BrP. Key messages Comparing with the use of HRS/EHRA/APHRS criteria, the number of individuals with Brugada ECG patterns was decreased by 71% when applying the ISHNE criteria. The prognosis of individuals with Brugada ECG patterns defined by 2012 ISHNE or 2013 HRS/EHRA/APHRS criteria were not different.

The pathophysiology of cardio-renal syndrome (CRS) is complex. Hydronephrosis caused by urolithiasis may cause cytokine release and lead to cardiac dysfunction. The aim of this study was to evaluate cardiac function changes observed in patients who received double J placement using feasible biomarkers and echocardiography. This was a prospective, single-center study. Eighty-seven patients who presented with acute unilateral hydronephrosis and received ureteroscope stone manipulation were enrolled. Echocardiography and cytokines were measured on the day of the operation and 24 hours after the procedure. Changes before and after surgery were assessed by the paired t-test and Wilcoxon test. Correlation analyses between echocardiographic diastolic indices and cytokine levels were performed using Pearson's correlation coefficients. Patients with hydronephrosis showed a higher left atrium volume index (LAVI), decreased E', and increased E/ E' ratio, which indicated diastolic dysfunction. Patients with hydronephrosis also exhibited decreased global strain rates during isovolumetric relaxation (SRIVR) and E/ SRIVR, which confirmed the diastolic dysfunction. Significant reductions in LAVI, increases in SRIVR and decreases in E/ SRIVR were observed after the operation. Biomarkers, such as TGF-β and serum NT-proBNP, were significantly decreased after surgery. In addition, a significant correlation was observed between the post-surgical decrease in TGF-β1 and increase in SRIVR. Unilateral hydronephrosis causes cardiac diastolic dysfunction, and relieving hydronephrosis could improve diastolic function. Improvements in cardiac dysfunction can be evaluated by echocardiography and measuring cytokine levels. The results of this study will inform efforts to improve the early diagnosis of CRS and prevent further deterioration of cardiac function when treating patients with hydronephrosis.

Background: The type VI adenylyl cyclase (AC6) is a main contributor of cAMP production in the heart. The amino acid (aa) sequence of AC6 is highly homologous to that of another major cardiac adenylyl cyclase, AC5, except for its N-terminus (AC6-N, aa 1-86). Activation of AC6, rather than AC5, produces cardioprotective effects against heart failure, while the underlying mechanism remains to be unveiled. Using an AC6-null (AC6 -/- ) mouse and a knockin mouse with AC6-N deletion (AC6 ΔN/ΔN ), we aimed to investigate the cardioprotective mechanism of AC6 in the heart., Methods: Western blot analysis and immunofluorescence staining were performed to determine the intracellular distribution of AC6, AC6-ΔN (a truncated AC6 lacking the first 86 amino acids), and STAT3 activation. Activities of AC6 and AC6-ΔN in the heart were assessed by cAMP assay. Apoptosis of cardiomyocytes were evaluated by the TUNEL assay and a propidium iodine-based survival assay. Fibrosis was examined by collagen staining., Results: Immunofluorescence staining revealed that cardiac AC6 was mainly anchored on the sarcolemmal membranes, while AC6-ΔN was redistributed to the sarcoplasmic reticulum. AC6 ΔN/ΔN and AC6 -/- mice had more apoptotic myocytes and cardiac remodeling than WT mice in experimental models of isoproterenol (ISO)-induced myocardial injury. Adult cardiomyocytes isolated from AC6 ΔN/ΔN or AC6 -/- mice survived poorly after exposure to ISO, which produced no effect on WT cardiomyocytes under the condition tested. Importantly, ISO treatment induced cardiac STAT3 phosphorylation/activation in WT mice, but not in AC6 ΔN/ΔN and AC6 -/- mice. Pharmacological blockage of PKA-, Src-, or STAT3- pathway markedly reduced the survival of WT myocytes in the presence of ISO, but did not affect those of AC6 ΔN/ΔN and AC6 -/- myocytes, suggesting an important role of AC6 in mediating cardioprotective action through the activation of PKA-Src-STAT3-signaling., Conclusions: Collectively, AC6-N controls the anchorage of cardiac AC6 on the sarcolemmal membrane, which enables the coupling of AC6 with the pro-survival PKA-STAT3 pathway. Our findings may facilitate the development of novel therapies for heart failure.

Essentials We studied the C-reactive protein (CRP) gene on stroke risk in atrial fibrillation (AF) patients. 725 patients with CRP triallelic polymorphism genotype were followed-up for more than 10 years. Patients with the A-390/T-390 allele of the CRP gene were more likely to get ischemic stroke. The triallelic polymorphism of the CRP is related to ischemic stroke in AF patients., Summary: Background Little evidence is available regarding the impact of genetic polymorphisms on the risk of thromboembolic stroke in patients with atrial fibrillation (AF). An increasing body of evidence is demonstrating that inflammatory responses play an important role in the pathophysiology of AF. Objectives To investigate the effect of genetic polymorphisms of the C-reactive protein (CRP) gene on the incidence of thromboembolic stroke in patients with AF. Methods A total of 725 AF patients were longitudinally followed up for > 10 years; this is the largest and longest AF follow-up cohort with genetic data. CRP promoter triallelic polymorphisms (C-390A and C-390T) were genotyped, and CRP levels were divided into four quartiles. Results Patients with higher CRP levels were more likely to develop thromboembolic stroke than those with lower CRP levels (P<0.001, log-rank test for comparison of four quartiles). After adjustment for conventional risk factors, patients with higher CRP levels were more likely to develop thromboembolic stroke than those in the lowest CRP quartile (hazard ratio [HR] 2.27, 95% confidence interval [CI] 1.08-4.81; the lowest CRP quartile was the reference group). Patients carrying the A-390 or T-390 allele had higher CRP levels (3.35 ± 2.71 mg L -1 versus 2.43 ± 2.00 mg L -1 ), and were more likely to develop thromboembolic stroke, even after adjustment for conventional risk factors (HR 2.07, 95% CI 1.23-3.48). Conclusion The CRP triallelic polymorphism and the CRP level are associated with the risk of incident thromboembolic stroke in patients with AF., (© 2017 International Society on Thrombosis and Haemostasis.)

Background/purpose: Atrial flutter/fibrillation (AFL/Af) is a common late complication in atrial septal defect (ASD) patients even after occluder implantation. We try to delineate the risk factors of persistent AFL/Af., Methods: From 1998 to 2010, all patients older than 18 years of age who received ASD occluder implantation in our hospital were enrolled, and their records were retrospectively reviewed. In addition, renin-angiotensin system gene polymorphisms including angiotensinogen gene, A1166C polymorphism on the angiotensin II type I receptor gene, and insertion/deletion (I/D) patterns on the angiotensin-converting enzyme gene were checked using direct sequencing., Results: A total of 517 patients (male/female 127/390) were enrolled. The mean age of patients receiving occluder deployment was 41.5 ± 14.5 years. Prior to occluder deployment, 3.9% of patients had persistent Af, 3.1% of patients had paroxysmal Af, and 0.8% had AFL. After a follow-up of 1894 patient-years, 3.5% had persistent Af and 1.9% of patients had paroxysmal Af. The greatest risk factors of AFL/Af genesis included age, occluder size, presence of multiple ASDs, and underlying thyroid or mitral valve disorder (p < 0.001, p < 0.001, p = 0.033, p = 0.016, and p = 0.012, respectively). Preoperative AFL/Af status is the most important factor in determining AFL/Af resolution and progression after an intervention. The renin-angiotensin system gene polymorphisms had no association with AFL/Af genesis, and progression or resolution after intervention., Conclusion: AFL/Af is common after ASD occluder implantation, and predisposed by older age, larger and multiple ASDs, and underlying disorders. Preoperative atrial arrhythmia status is the most important predictor of AFL/Af progression or resolution. Renin-angiotensin system gene polymorphisms had no association with AFL/Af., (Copyright © 2016. Published by Elsevier B.V.)

Several studies have shown the beneficial effect of renal denervation (RDN) in the treatment of ventricular arrhythmia, especially in the setting of heart failure (HF). However, the underlying mechanism of antiarrhythmic effect of RDN is unknown. Arrhythmogenic cardiac alternans, particularly spatially discordant repolarization alternans, characterized by simultaneous prolongation and shortening of action potential duration (APD) in different myocardial regions, is central to the genesis of ventricular fibrillation in HF. Whether RDN decreases the susceptibility to arrhythmogenic cardiac alternans in HF has never been addressed before. The authors used a rat model of post-myocardial infarction HF and dual voltage-calcium optical mapping to investigate whether RDN could attenuate arrhythmogenic cardiac alternans that predisposes to ventricular arrhythmias, as well as the hemodynamic effect of RDN in HF. The HF rats had increased body weights, dilated hearts, and lower blood pressure. The HF rats also had longer ventricular APDs and a delay in the decay of the calcium transient, typical electrophysiological features of human HF. Susceptibility to calcium transient alternans, APD alternans, and spatially discordant APD alternans was increased in the HF hearts. RDN significantly attenuated a delay in the decay of the calcium transient, calcium transient and APD alternans, and importantly, the discordant APD alternans, and thereby decreased the incidence of induced ventricular arrhythmia in HF. RDN did not further decrease blood pressure in HF rats. In conclusion, RDN improves calcium cycling and prevents spatially discordant APD alternans and ventricular arrhythmia in HF. RDN does not aggravate hemodynamics in HF.

Potassium calcium-activated channel subfamily N member 2 (KCNN2) encodes an integral membrane protein that forms small-conductance calcium-activated potassium (SK) channels. Recent studies in animal models show that SK channels are important in atrial and ventricular repolarization and arrhythmogenesis. However, the importance of SK channels in human arrhythmia remains unclear. The purpose of the present study was to test the association between genetic polymorphism of the SK2 channel and the occurrence of cardiac tachyarrhythmias in humans. We enrolled 327 Han Chinese, including 72 with clinically significant ventricular tachyarrhythmias (VTa) who had a history of aborted sudden cardiac death (SCD) or unexplained syncope, 98 with a history of atrial fibrillation (AF), and 144 normal controls. We genotyped 12 representative tag single nucleotide polymorphisms (SNPs) across a 141-kb genetic region containing the KCNN2 gene; these captured the full haplotype information. The rs13184658 and rs10076582 variants of KCNN2 were associated with VTa in both the additive and dominant models (odds ratio [OR] 2.89, 95% confidence interval [CI] = 1.505-5.545, P = 0.001; and OR 2.55, 95% CI = 1.428-4.566, P = 0.002, respectively). After adjustment for potential risk factors, the association remained significant. The population attributable risks of these 2 variants of VTa were 17.3% and 10.6%, respectively. One variant (rs13184658) showed weak but significant association with AF in a dominant model (OR 1.91, CI = 1.025-3.570], P = 0.042). There was a significant association between the KCNN2 variants and clinically significant VTa. These findings suggest an association between KCNN2 and VTa; it also appears that KCNN2 variants may be adjunctive markers for risk stratification in patients susceptible to SCD., Competing Interests: The remaining authors have no conflicts of interest to disclose.

Background: Green tea intake has been shown to improve endurance capacity in animal studies, but whether it has a similar effect on humans remains unclear. A randomized, double-blinded, parallel-controlled study was conducted to evaluate the short-term effect of STA-2, a pharmaceutical preparation of green tea polyphenols, in patients with effort-induced angina and documented positive exercise tolerance test., Methods: A total of 79 patients recruited from three medical centers were randomly assigned to receive 2 STA-2 250 mg capsules, each containing 100 mg green tea polyphenols, three times daily, or placebo for six weeks after two consecutive symptom-limited treadmill exercise tests to ascertain the reproducibility of exercise tolerance., Results: There was no difference in total exercise tolerance time from baseline to Week 6 between two groups (p = 0.639). There were also no observed improvements in subgroup analyses stratified by age, gender, and BMI categories. However, a significant reduction in low-density lipoprotein levels was shown in patients in the STA-2 group (-8.99 ± 19.18 mg/dL) versus the placebo group (0.57 ± 19.77 mg/dL), p = 0.037, with greater benefits in patients not taking antihyperlipidemic drugs (STA-2: -9.10 ± 19.96 mg/dL vs. placebo: 4.42 ± 15.08 mg/dL, p = 0.037)., Conclusions: STA-2 treatment for 6 weeks did not increase exercise time as measured on a treadmill. However, this study also indicated that STA-2 treatment could have potential beneficial effects on LDL-cholesterol concentrations.

In extant species, bone formation is restricted to vertebrate species. Sp7/Osterix is a key transcriptional determinant of bone-secreting osteoblasts. We performed Sp7 chromatin immunoprecipitation sequencing analysis identifying a large set of predicted osteoblast enhancers and validated a subset of these in cell culture and transgenic mouse assays. Sp family members bind GC-rich target sequences through their zinc finger domain. Several lines of evidence suggest that Sp7 acts differently, engaging osteoblast targets in Dlx-containing regulatory complexes bound to AT-rich motifs. Amino acid differences in the Sp7 zinc finger domain reduce Sp7's affinity for the Sp family consensus GC-box target; Dlx5 binding maps to this domain of Sp7. The data support a model in which Dlx recruitment of Sp7 to osteoblast enhancers underlies Sp7-directed osteoblast specification. Because an Sp7-like zinc finger variant is restricted to vertebrates, the emergence of an Sp7 member within the Sp family was likely closely coupled to the evolution of bone-forming vertebrates., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Aim: To trace the cell origin of the cells involved in postnatal cardiomyogenesis., Materials & Methods: Nkx2.5 enhancer-eGFP (Nkx2.5 enh-eGFP) mice were used to test the cardiomyogenic potential of Nkx2.5 enhancer-expressing cells. By analyzing Cre excision of activated Nkx2.5-eGFP+ cells from different lineage-Cre/Nkx2.5 enh-eGFP/ROSA26 reporter mice, we traced the developmental origin of Nkx2.5 enhancer-expressing cells., Results: Nkx2.5 enhancer-expressing cells could differentiate into striated cardiomyocytes both in vitro and in vivo . Nkx2.5-eGFP+ cells increased remarkably after experimental myocardial infarction (MI). The post-MI Nkx2.5-eGFP+ cells originated from the embryonic epicardial cells, not from the pre-existing cardiomyocytes, endothelial cells, cardiac neural crest cells or perinatal/postnatal epicardial cells., Conclusion: Postnatal Nkx2.5 enhancer-expressing cells are cardiomyogenic progenitor cells and originate from embryonic epicardium-derived cells., Competing Interests: Financial & competing interests disclosure This study was supported by grants of Far Eastern Memorial Hospital (FEMH 98–2314-B-418-004-MY2, FEMH-98-SCRM-B-002, FEMH-99-SCRM-A-005, FEMH-2011-SCRM-A-007, FEMH-2013-C-024, FEMH-2013-SCRM-A-004, FEMH-2014-SCRM-007, FEMH-2014-C-029, FEMH-2015-C-010), Far Eastern Memorial Hospital National Taiwan University Hospital Joint Research Program (99-FTN05, 100-FTN03, 101-FTN12, 102-FTN05, 103-FTN06), and the National Scientific Council (NSC 98-2314-B-418–004-MY2). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.

Left ventricular (LV) dyssynchrony is associated with poor prognosis in patients with heart failure (HF). The mechanisms leading to LV dyssynchrony are not fully elucidated. This study evaluates whether myocardium regional variation in interstitial fibrosis is associated with LV dyssynchrony. Forty-two patients with systolic heart failure (SHF), 76 patients with heart failure with preserved ejection fraction (HFpEF) and 20 patients without HF received cardiovascular magnetic resonance imaging (MRI) study. LV was divided into 18 segments by short-axis view. In each segment, regional extracellular volume fraction (ECV) and the time taken to reach minimum regional volume (Tmv) were derived. Intra-LV dyssynchrony were represented by maximum difference (Dysyn&#95;max) and standard deviation (Dysyn&#95;sd) of all Tmv. The results showed that among the covariates, only age (1.87, 95% CI: 0.61-3.13, p = 0.004) and ECV (3.77, 95% CI: 2.72-4.81, p < 0.001) were positively associated with Tmv. The results remained robust in certain subgroups. In conclusion, we demonstrated that LV myocardium regional variation in interstitial fibrosis is closely related to LV intra-ventricular dyssynchrony irrespective of the LV global function. These data might help explain the pathophysiology of LV dyssynchrony and it's underlying mechanisms leading to poor prognosis.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Previous genome-wide association studies had identified single-nucleotide polymorphisms in several genomic regions to be associated with AF. In human genome, copy number variations (CNVs) are known to contribute to disease susceptibility. Using a genome-wide multistage approach to identify AF susceptibility CNVs, we here show a common 4,470-bp diallelic CNV in the first intron of potassium interacting channel 1 gene (KCNIP1) is strongly associated with AF in Taiwanese populations (odds ratio=2.27 for insertion allele; P=6.23 × 10(-24)). KCNIP1 insertion is associated with higher KCNIP1 mRNA expression. KCNIP1-encoded protein potassium interacting channel 1 (KCHIP1) is physically associated with potassium Kv channels and modulates atrial transient outward current in cardiac myocytes. Overexpression of KCNIP1 results in inducible AF in zebrafish. In conclusions, a common CNV in KCNIP1 gene is a genetic predictor of AF risk possibly pointing to a functional pathway.