Skin sympathetic nerve activity as a potential biomarker for overactive bladder.

PURPOSE: Abnormalities in autonomic function are associated with an overactive bladder (OAB). Heart rate variability is generally used as the sole assessment of autonomic activity; however, we utilized neuECG, a novel method of recording skin electrical signals, to assess autonomic nervous function in healthy controls and patients with OAB before and after treatment. METHODS: The prospective sample included 52 participants: 23 patients newly diagnosed with OAB and 29 controls. Autonomic function was assessed in all participants in the morning using neuECG, which analyzed the average skin sympathetic nerve activity (aSKNA) and electrocardiogram simultaneously. All patients with OAB were administered antimuscarinics; urodynamic parameters were assessed before treatments; autonomic and bladder functions using validated questionnaires for OAB symptoms were evaluated before and after OAB treatment. RESULTS: Patients with OAB had significantly higher baseline aSKNA (p = 0.003), lower standard deviation of the normal-to-normal beat intervals, lower root mean square of the successive differences, lower high-frequency, and higher low-frequency than did controls. Baseline aSKNA had the highest value in predicting OAB (AUROC = 0.783, p < 0.001). The aSKNA was negatively correlated with first desire and normal desire in urodynamic studies (both p = 0.025) and was significantly decreased after treatment at rest, stress, and recovery phases, as compared to those before treatment (p = 0.046, 0.017, and 0.017, respectively). CONCLUSION: Sympathetic activity increased significantly in patients with OAB compared to that in healthy controls, and decreased significantly post-treatment. Higher aSKNA is associated with decreased bladder volume at which voiding is desired. SKNA may be a potential biomarker for diagnosing OAB.

Up-regulated small-conductance calcium-activated potassium currents contribute to atrial arrhythmogenesis in high-fat feeding mice.

AIMS: Metabolic syndrome (MetS) is associated with arrhythmias and cardiovascular mortality. Arrhythmogenesis in MetS results from atrial structural and electrical remodelling. The small-conductance Ca2+-activated K+ (SK) currents modulate atrial repolarization and may influence atrial arrhythmogenicity. This study investigated the regulation of SK current perturbed by a high-fat diet (HFD) to mimic MetS. METHODS AND RESULTS: Thirty mice were divided into two groups that were fed with normal chow (CTL) and HFD for 4 months. Electrocardiography and echocardiography were used to detect cardiac electrical and structure remodelling. Atrial action potential duration (APD) and calcium transient duration (CaTD) were measured by optical mapping of Langendorff-perfused mice hearts. Atrial fibrillation (AF) inducibility and duration were assessed by burst pacing. Whole-cell patch clamp was performed in primarily isolated atrial myocytes for SK current density. The SK current density is higher in atrial myocytes from HFD than in CTL mice (P ≤ 0.037). The RNA and protein expression of SK channels are increased in HFD mice (P ≤ 0.041 and P ≤ 0.011, respectively). Action potential duration is shortened in HFD compared with CTL (P ≤ 0.015). The shortening of the atrial APD in HFD is reversed by the application of 100 nM apamin (P ≤ 0.043). Compared with CTL, CaTD is greater in HFD atria (P ≤ 0.029). Calcium transient decay (Tau) is significantly higher in HFD than in CTL (P = 0.001). Both APD and CaTD alternans thresholds were higher in HFD (P ≤ 0.043), along with higher inducibility and longer duration of AF in HFD (P ≤ 0.023). CONCLUSION: Up-regulation of apamin-sensitive SK currents plays a partial role in the atrial arrhythmogenicity of HFD mice.

Automated ECG classification based on 1D deep learning network.

The standard 12-lead electrocardiogram (ECG) records the heart's electrical activity from electrodes on the skin, and is widely used in screening and diagnosis of the cardiac conditions due to its low price and non-invasive characteristics. Manual examination of ECGs requires professional medical skills, and is strenuous and time consuming. Recently, deep learning methodologies have been successfully applied in the analysis of medical images. In this paper, we present an automated system for the identification of normal and abnormal ECG signals. A multi-channel multi-scale deep neural network (DNN) model is proposed, which is an end-to-end structure to classify the ECG signals without any feature extraction. Convolutional layers are used to extract primary features, and long short-term memory (LSTM) and attention are incorporated to improve the performance of the DNN model. The system was developed with a 12-lead ECG dataset provided by the Kaohsiung Medical University Hospital (KMUH). Experimental results show that the proposed system can yield high recognition rates in classifying normal and abnormal ECG signals.

Higher pre-treatment skin sympathetic nerve activity and elevated resting heart rate after chemoradiotherapy predict worse esophageal cancer outcomes.

BACKGROUND: Chemoradiotherapy (CRT), which might affect the autonomic system, is the mainstay therapy for advanced esophageal squamous cell carcinoma (ESCC). Autonomic dysfunction has been found to possibly lead to cancer mortality in those with elevated resting heart rates (RHR). Skin sympathetic nerve activity (SKNA) is a new method of stimulating electrical signals in skin to evaluate autonomic function from sympathetic tone. In this study, we investigated the association between changes in RHR and autonomic function and ESCC mortality. METHODS: Thirty-nine stage II-IV ESCC patients receiving CRT between March 2019 and November 2020 were prospectively enrolled and carefully selected, followed up and received the same meticulous supportive care. Serial RHR was recorded every two weeks from before CRT to eight weeks after CRT and average SKNA were recorded before and four weeks after CRT. All-cause mortality was defined as primary outcome. RESULTS: We found the RHR of ESCC patients to be significantly elevated and peaking at four weeks after CRT (p < 0.001) and then to gradually decrease. Those with an elevated RHR above the cutoff level (18 beat-per-minute) at eight weeks after CRT had worse overall survival. In addition, those with higher baseline sympathetic tone (average SKNA ≥ 0.86 µV) also had poor outcome. CONCLUSIONS: Increased pre-treatment sympathetic tone and elevated RHR after CRT are alarm signs of poor ESCC outcome. Further exploration of the mechanisms underlying these associations could potentially lead to intervention strategies for reducing mortality. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov, identifier: NCT03243448.

Usefulness of Ankle-Brachial Index Calculated Using Diastolic Blood Pressure and Mean Arterial Pressure in Predicting Overall and Cardiovascular Mortality in Hemodialysis Patients.

No study has investigated the predictive ability of ankle-brachial index (ABI) calculated using diastolic blood pressure (DBP) (ABIdbp) and mean arterial pressure (MAP) (ABImap) for overall and cardiovascular (CV) mortality in hemodialysis (HD) patients. Our study was aimed to investigate the issue. Two hundred and seven routine HD patients were enrolled. ABI values were measured by ABI-form device. During the follow-up period (122 months), 124 of the 207 patients (59.0%) died, and 59 deaths due to CV cause. Multivariate analysis showed that low ABIsbp, ABIdbp, and ABImap were all significantly associated with increased overall (p ≤ 0.015) and CV mortality (p ≤ 0.015) in whole study patients. A subgroup analysis after excluding 37 patients with ABIsbp < 0.9 or > 1.3 found ABIsbp and ABIsbp < 0.9 were not associated with overall and CV mortality. However, ABImap and ABIdbp < 0.87 were significantly associated with overall mortality (p ≤ 0.042). Furthermore, ABIdbp and ABIdbp < 0.87 were significantly associated with CV mortality (p ≤ 0.030). In conclusion, ABIsbp, ABIdbp, and ABImap were all useful in predicting overall and CV mortality in our HD patients. In the subgroup patients with normal ABIsbp, ABIsbp and ABIsbp < 0.9 were not useful to predict overall and CV mortality. Nevertheless, ABImap and ABIdbp < 0.87 could still predict overall mortality, and ABIdbp and ABIdbp < 0.87 could predict CV mortality. Hence, calculating ABI using DBP and MAP may provide benefit in survival prediction in HD patients, especially in the patients with normal ABIsbp.

Using CHADS2, R2CHADS2, CHA2DS2-VASc score for mortality prediction in patients with abnormal low and high ankle-brachial index.

Abnormal low and high ankle brachial index (ABI) is regarded as peripheral artery disease (PAD) which has extremely high morbidity and mortality. How to identify high-risk PAD patients with increased mortality is very important to improve the outcome. CHADS2, R2CHADS2, and CHA2DS2-VASc score are clinically useful scores to evaluate the annual risk of stroke in patients with atrial fibrillation. However, there was no literature discussing the usefulness of these scores for cardiovascular (CV) and all-cause mortality prediction in the patients with abnormal ABI. This longitudinal study enrolled 195 patients with abnormal low (< 0.9) and high ABI (> 1.3). CHADS2, R2CHADS2, and CHA2DS2-VASc score were calculated for each patient. CV and all-cause mortality data were collected for outcome prediction. The median follow-up to mortality was 90 months. After multivariate analysis, CHADS2, R2CHADS2, and CHA2DS2-VASc score were significant predictors of CV and all-cause mortality (all P < 0.001). CHA2DS2-VASc score had a better additive predictive value than CHADS2 and R2CHADS2 score for CV mortality prediction. R2CHADS2 and CHA2DS2-VASc score had better additive predictive values than CHADS2 score for all-cause mortality prediction. In conclusion, our study is the first study to investigate the usefulness of CHADS2, R2CHADS2, and CHA2DS2-VASc score for mortality prediction in patients with abnormal ABI. Our study showed all three scores are significant predictors for CV and all-cause mortality although there are some differences between the scores. Therefore, using the three scoring systems may help physicians to identify the high-risk PAD patients with increased mortality.

Anti-Allergic Diarrhea Effect of Diosgenin Occurs via Improving Gut Dysbiosis in a Murine Model of Food Allergy.

Although the anti-allergic and prebiotic activities of diosgenin have been reported, the influence of diosgenin on intestinal immune and epithelial cells remains unclear. As the gut microbiota plays an important role in allergic disorders, this study aimed to investigate whether the anti-allergic diarrhea effect of diosgenin occurs via improving gut dysbiosis. In a murine food allergy model, the density of fecal bacterial growth on de Man, Rogossa and Sharpe (MRS) plates was diminished, and growth on reinforced clostridial medium (RCM) and lysogeny broth (LB) agar plates was elevated. However, the oral administration of diosgenin reduced the density of fecal bacteria and ameliorated diarrhea severity. Concordantly, reshaped diversity and an abundance of fecal microbes were observed in some of the diosgenin-treated mice, which showed a milder severity of diarrhea. The relevant fecal strains from the diosgenin-treated mice were defined and cultured with Caco-2 cells and allergen-primed mesenteric lymph node (MLN) cells. These strains exhibited protective effects against the cytokine/chemokine network and allergen-induced T-cell responses to varying degrees. By contrast, diosgenin limitedly regulated cytokine production and even reduced cell viability. Taken together, these findings show that diosgenin per se could not directly modulate the functionality of intestinal epithelial cells and immune cells, and its anti-allergic effect is most likely exerted via improving gut dysbiosis.

CHA2DS2-VASc Score and Risk of New-Onset Peripheral Arterial Occlusive Disease in Patients without Atrial Fibrillation.

BACKGROUND: CHA2DS2-VASc score is a useful score to evaluate the risk of stroke in patients with atrial fibrillation (AF), and it has been shown to outperform CHADS2 score. Our recent cross-sectional study showed that CHA2DS2-VASc score was associated with an ankle-brachial index < 0.9. The aim of the current study was to evaluate whether CHA2DS2-VASc score is a useful predictor of new-onset peripheral artery occlusive disease (PAOD) and whether it can outperform CHADS2 and R2CHADS2 scores. METHODS: We used the National Health Insurance Research Database to survey 723750 patients from January 1, 2000 to December 31, 2001. CHADS2, R2CHADS2, and CHA2DS2-VASc scores were calculated for every patient. Finally, 280176 (score 0), 307209 (score 1), 61093 (score 2), 35594 (score 3), 18956 (score 4), 11032 (score 5), 6006 (score 6), 2696 (score 7), 843 (score 8), and 145 (score 9) patients were studied and followed to evaluate new-onset PAOD. We further divided the study patients into six groups: group 1 (score 0), group 2 (score 1-2), group 3 (score 3-4), group 4 (score 5-6), group 5 (score 7-8), and group 6 (score 9). RESULTS: Overall, 24775 (3.4%) patients experienced new-onset PAOD during 9.8 years of follow-up. The occurrence rate of PAOD increased from 1.3% (group 1) to 23.4% (group 6). Subgroup analysis by gender also showed an association between CHA2DS2-VASc score and the occurrence rate of PAOD. After multivariate analysis, groups 2-6 were significantly associated with new-onset PAOD. CHA2DS2-VASc score also outperformed CHADS2 and R2CHADS2 scores for predicting new-onset PAOD. CONCLUSIONS: CHA2DS2-VASc score was a more powerful predictor of new-onset PAOD than CHADS2 and R2CHADS2 scores in patients without AF.

Usefulness of four-limb blood pressure measurement in prediction of overall and cardiovascular mortality in acute myocardial infarction.

Four-limb blood pressure measurement could improve mortality prediction in the elderly. However, there was no study to evaluate whether such measurement was still useful in predicting overall and cardiovascular (CV) mortality in acute myocardial infarction (AMI). Two hundred AMI patients admitted to cardiac care unit were enrolled. The 4-limb blood pressures, inter-limb blood pressure differences, and ankle brachial index (ABI) were measured using an ABI-form device. The median follow-up to mortality was 64 months (25th-75th percentile: 5-174 months). There were 40 and 138 patients documented as CV and overall mortality, respectively. After multivariable adjustment, the ankle diastolic blood pressure (DBP) on the lower side, ABI value, ABI < 0.9, interarm DBP difference, interankle systolic blood pressure (SBP) and DBP differences, interankle SBP difference ≥ 15 mmHg, and interankle DBP difference ≥ 10 mmHg could predict overall mortality (P ≤ 0.025). The ankle DBP on the lower side, interankle DBP difference, and interankle DBP difference ≥ 10 mmHg could predict CV mortality (P ≤ 0.031). In addition, in the Nested Cox model, the model including the ankle DBP on the lower side and the model including interankle DBP difference had the best value for overall and CV mortality prediction, respectively (P ≤ 0.031). In AMI patients, 4-limb blood pressure measurement could generate several useful parameters in predicting overall and CV mortality. Furthermore, ankle DBP on the lower side and interankle DBP difference were the most powerful parameters in prediction of overall and CV mortality, respectively.

Cardiovascular disease management during the coronavirus disease 2019 pandemic.

Based on clinical presentation, pathophysiology, high infectivity, high cardiovascular involvement, and therapeutic agents with cardiovascular toxicity of coronavirus disease 2019 (COVID-19), regular cardiovascular treatment is being changing greatly. Despite angiotensin-converting enzyme 2 serving as the portal for infection, the continuation of clinically indicated renin-angiotensin-aldosterone blockers is recommended according to the present evidence. Fibrinolytic therapy can be considered a reasonable option for the relatively stable ST segment elevation myocardial infarction (STEMI) patient with suspected or known COVID-19. However, primary percutaneous coronary intervention is still the standard of care in patients with definite STEMI if personal protective equipment is available and cardiac catheterization laboratory has a good infection control. In patients with elevated cardiac enzymes, it is very important to differentiate patients with Type 2 myocardial infarction or myocarditis from those with true acute coronary syndromes because invasive percutaneous intervention management in the former may be unnecessary, especially if they are hemodynamically stable. Finally, patients with baseline QT prolongation or those taking QT prolonging drugs must be cautious when treating with lopinavir/ritonavir and hydroxychloroquine for COVID-19.

The role of postprandial very-low-density lipoprotein in the development of atrial remodeling in metabolic syndrome.

BACKGROUND: Negatively charged very-low-density lipoprotein (VLDL-χ) in metabolic syndrome (MetS) patients exerts cytotoxic effects on endothelial cells and atrial myocytes. Atrial cardiomyopathy, manifested by atrial remodeling with a dilated diameter, contributes to atrial fibrillation pathogenesis and predicts atrial fibrillation development. The correlation of VLDL-χ with atrial remodeling is unknown. This study investigated the association between VLDL-χ and remodeling of left atrium. METHODS: Consecutively, 87 MetS and 80 non-MetS individuals between 23 and 74 years old (50.6% men) without overt cardiovascular diseases were included in the prospective cohort study. Blood samples were collected while fasting and postprandially (at 0.5, 1, 2, and 4 h after a unified meal). VLDL was isolated by ultracentrifugation; the percentile concentration of VLDL-χ (%) was determined by ultra-performance liquid chromatography. The correlations of left atrium diameter (LAD) with variables including VLDL-χ, LDL-C, HDL-C, triglycerides, glucose, and blood pressure, were analyzed by multiple linear regression models. A hierarchical linear model was conducted to test the independencies of each variable's correlation with LAD. RESULTS: The mean LAD was 3.4 ± 0.5 cm in non-MetS subjects and 3.9 ± 0.5 cm in MetS patients (P < 0.01). None of the fasting lipid profiles were associated with LAD. VLDL-χ, BMI, waist circumference, hip circumference, and blood pressure were positively correlated with LAD (all P < 0.05) after adjustment for age and sex. Significant interactions between VLDL-χ and blood pressure, waist circumference, and hip circumference were observed. When adjusted for obesity- and blood pressure-related variables, 2-h postprandial VLDL-χ (mean 1.30 ± 0.61%) showed a positive correlation with LAD in MetS patients. Each 1% VLDL-χ increase was estimated to increase LAD by 0.23 cm. CONCLUSIONS: Postprandial VLDL-χ is associated with atrial remodeling particularly in the MetS group. VLDL-χ is a novel biomarker and may be a therapeutic target for atrial cardiomyopathy in MetS patients. TRIAL REGISTRATION: ISRCTN 69295295 . Retrospectively registered 9 June 2020.

Effects of Lipids and Lipoproteins on Mesenchymal Stem Cells Used in Cardiac Tissue Regeneration.

Mesenchymal stem cells (MSCs) have two characteristics of interest for this paper: the ability to self-renew, and the potential for multiple-lineage differentiation into various cells. MSCs have been used in cardiac tissue regeneration for over a decade. Adult cardiac tissue regeneration ability is quite low; it cannot repair itself after injury, as the heart cells are replaced by fibroblasts and lose function. It is therefore important to search for a feasible way to repair and restore heart function through stem cell therapy. Stem cells can differentiate and provide a source of progenitor cells for cardiomyocytes, endothelial cells, and supporting cells. Studies have shown that the concentrations of blood lipids and lipoproteins affect cardiovascular diseases, such as atherosclerosis, hypertension, and obesity. Furthermore, the MSC lipid profiles, such as the triglyceride and cholesterol content, have been revealed by lipidomics, as well as their correlation with MSC differentiation. Abnormal blood lipids can cause serious damage to internal organs, especially heart tissue. In the past decade, the accumulated literature has indicated that lipids/lipoproteins affect stem cell behavior and biological functions, including their multiple lineage capability, and in turn affect the outcome of regenerative medicine. This review will focus on the effect of lipids/lipoproteins on MSC cardiac regenerative medicine, as well as the effect of lipid-lowering drugs in promoting cardiomyogenesis-associated MSC differentiation.

Effects of Secretome from Fat Tissues on Ion Currents of Cardiomyocyte Modulated by Sodium-Glucose Transporter 2 Inhibitor.

Sodium-glucose transporter 2 (SGLT2) inhibitors were shown to decrease mortality from cardiovascular diseases in the EMPA-REG trial. However, the effects of empagliflozin (EMPA) for cardiac arrhythmia are not yet clarified. A total of 20 C57BL/6J mice were divided into four groups: (1) The control group were fed standard chow, (2) the metabolic syndrome (MS) group were fed a high-fat diet, (3) the empagliflozin (EMPA) group were fed a high-fat diet and empagliflozin 10 mg/kg daily, and (4) the glibenclamide (GLI) group were fed a high-fat diet and glibenclamide 0.6 mg/kg daily. All mice were sacrificed after 16 weeks of feeding. H9c2 cells were treated with adipocytokines from the pericardial and peripheral fat from the study groups. The delayed-rectifier potassium current (IK) and L-type calcium channel current (ICa,L) were measured by the whole-cell patch clamp techniques. Adipocytokines from the peripheral and pericardial fat tissues of mice with MS could decrease the IK and increase the ICa,L of cardiomyocytes. After treating adipocytokines from pericardial fat, the IK in the EMPA and GLI groups were significantly higher than that in the MS group. The IK of the EMPA group was also significantly higher than the GLI group. The ICa,L of the EMPA and GLI groups were significantly decreased overload compared with that of the MS group. However, there was no significant difference of IK and ICa,L among study groups after treating adipocytokines from peripheral fat. Adipocytokines from pericardial fat but not peripheral fat tissues after EMPA therapy attenuated the effects of IK decreasing and ICa,L increasing in the MS cardiomyocytes, which may contribute to anti-arrhythmic mechanisms of sodium-glucose transporter 2 (SGLT2) inhibitors.

2019 Consensus Statement of the Taiwan Hypertension Society and the Taiwan Society of Cardiology on Renal Denervation for the Management of Arterial Hypertension.

Sympathetic overactivity, an essential mechanism of hypertension, in driving sustained hypertension derives mostly from its effects on renal function. Percutaneous renal denervation (RDN) is designed to disrupt renal afferent and efferent sympathetic nerves to achieve sustained blood pressure (BP) reduction. Since 2017 onward, all three proof-of-concept, sham-controlled RDN trials demonstrated that RDN achieved consistent and clinically meaningful BP reductions [approximately 10 mmHg in office systolic BP (SBP) and 6-9 mmHg in 24-hour SBP] compared to sham operation in patients with mild to moderate or uncontrolled hypertension. There were no serious adverse events. The registry data in Taiwan showed similar 24-hour BP reductions at 12 months following RDN. The Task Force considers RDN as a legitimate alternative antihypertensive strategy and recommends 1) RDN should be performed in the context of registry and clinical studies (Class I, Level C) and 2) RDN should not be performed routinely, without detailed evaluation of various causes of secondary hypertension and renal artery anatomy (Class III, Level C). RDN could be performed in patients who fulfill either of the following BP criteria: 1) office BP ≥ 150/90 mmHg and daytime ambulatory SBP ≥ 135 mmHg or diastolic BP (DBP) ≥ 85 mmHg, irrespective of use of antihypertensive agents (Class IIa, Level B), or 2) 24-hour ambulatory SBP ≥ 140 mmHg and DBP ≥ 80 mmHg, irrespective of use of antihypertensive agents (Class IIa, Level B), with eligible renal artery anatomy and estimated glomerular filtration rate ≥ 45 mL/min/1.73 m2. Five subgroups of hypertensive patients are deemed preferred candidates for RDN and dubbed "RDN i2": Resistant hypertension, patients with hypertension-mediated organ Damage, Non-adherent to antihypertensive medications, intolerant to antihypertensive medications, and patients with secondary (2ndary) causes being treated for ≥ 3 months but BP still uncontrolled. The Task Force recommends assessment of three aspects, dubbed "RAS" (R for renal, A for ambulatory, S for secondary), beforehand to ascertain whether RDN could be performed appropriately: 1) Renal artery anatomy eligibility assessed by computed tomography or magnetic resonance renal angiography if not contraindicated, 2) genuine uncontrolled BP confirmed by 24-hour Ambulatory BP monitoring, and 3) Secondary hypertension identified and properly treated. After the procedure, 24-hour ambulatory BP monitoring, together with the dose and dosing interval of all BP-lowering drugs, should be obtained 6 months following RDN. Computed tomography or magnetic resonance renal angiography should be obtained 12 months following RDN, given that renal artery stenosis might not be clinically evident.

The association of the amounts of epicardial fat, P wave duration, and PR interval in electrocardiogram.

BACKGROUND: The relationship of epicardial fat and cardiac arrhythmias has been described in many studies. The association of the amounts of epicardial fat and the characteristics of electrocardiogram (ECG) remains unclear. The purpose of this study was to elucidate the association between the amounts of epicardial fat and the characteristics of ECG. METHODS: A total of 100 consecutive patients who received multi-detector computer tomography (MDCT) were enrolled. The amounts of epicardial fat, including total heart, total atria, total ventricles, right atrium (RA), right ventricle (RV), left atrium (LA), and left ventricle (LV) regions, were measured. The PR interval in lead II, the P wave duration in lead I, the characteristics of inter-atrial conduction block manifested in ECG, the corrected QT interval (QTc) and the QT dispersion of a 12­lead ECG were measured manually by a computer caliper. RESULTS: The PR interval was correlated with the amounts of epicardial fat including total heart, total atria, total ventricles, RA, RV, LA, and LV (R = 0.295, p = 0.003; R = 0.379, p < 0.001; R = 0.284, p = 0.003; R = 0.415, p < 0.001; R = 0.287, p < 0.001; R = 0.33, p < 0.001; R = 0.244, p = 0.014). The P wave duration of lead I was also correlated with the amounts of epicardial fat (R = 0.202, p = 0.043; R = 0.283, p = 0.004; R = 0.225, p = 0.024; R = 0.365, p < 0.001; R = 0.256, p = 0.001; R = 0.20, p = 0.046; R = 0.199, p = 0.048) but the QTc interval and the QT dispersion were not. Inter-atrial conduction block was also associated with the amounts of epicardial fat, including total atria, RA and LA in univariate analysis (odds ratio (OR): 1.04, 95% of confidence interval (CI): 1.01-1.06, p = 0.015; OR: 1.08, 95% CI: 1.02-1.15, p = 0.011; OR: 1.05, 95% CI: 1.01-1.10, p = 0.031). In multivariate analysis of linear regression, the amounts of RA epicardial fat was most significantly associated with the PR interval, and the P wave duration (ß value: 1.30, 95% CI: 0.59-2.02, p < 0.001; ß value: 0.81, 95% CI: 0.34-1.28, p = 0.001). In multivariate analysis of logistic regression, inter-atrial conduction block was also significantly associated with the amounts of RA epicardial fat (odds ratio (OR): 1.08, 95% CI: 1.02-1.15, p = 0.011). CONCLUSIONS: The PR interval, P wave duration and inter-atrial conduction block were associated with the amounts of epicardial fat, which might imply an effect for arrhythmogenesis.

Small-Conductance Calcium-Activated Potassium Current Is Activated During Hypokalemia and Masks Short-Term Cardiac Memory Induced by Ventricular Pacing.

BACKGROUND: Hypokalemia increases the vulnerability to ventricular fibrillation. We hypothesize that the apamin-sensitive small-conductance calcium-activated potassium current (IKAS) is activated during hypokalemia and that IKAS blockade is proarrhythmic. METHODS AND RESULTS: Optical mapping was performed in 23 Langendorff-perfused rabbit ventricles with atrioventricular block and either right or left ventricular pacing during normokalemia or hypokalemia. Apamin prolonged the action potential duration (APD) measured to 80% repolarization (APD80) by 26 milliseconds (95% confidence interval [CI], 14-37) during normokalemia and by 54 milliseconds (95% CI, 40-68) during hypokalemia (P=0.01) at a 1000-millisecond pacing cycle length. In hypokalemic ventricles, apamin increased the maximal slope of APD restitution, the pacing cycle length threshold of APD alternans, the pacing cycle length for wave-break induction, and the area of spatially discordant APD alternans. Apamin significantly facilitated the induction of sustained ventricular fibrillation (from 3 of 9 hearts to 9 of 9 hearts; P=0.009). Short-term cardiac memory was assessed by the slope of APD80 versus activation time. The slope increased from 0.01 (95% CI, -0.09 to 0.12) at baseline to 0.34 (95% CI, 0.23-0.44) after apamin (P<0.001) during right ventricular pacing and from 0.07 (95% CI, -0.05 to 0.20) to 0.54 (95% CI, 0.06-1.03) after apamin infusion (P=0.045) during left ventricular pacing. Patch-clamp studies confirmed increased IKAS in isolated rabbit ventricular myocytes during hypokalemia (P=0.038). CONCLUSIONS: Hypokalemia activates IKAS to shorten APD and maintain repolarization reserve at late activation sites during ventricular pacing. IKAS blockade prominently lengthens the APD at late activation sites and facilitates ventricular fibrillation induction.

Statin Dose and the Risk of Intracerebral Hemorrhage: A Population-Based Longitudinal Study in Taiwan.

BACKGROUND: In the last 15 years, there has been considerable interest in statin use as a means to reduce the likelihood of vascular events. Several clinical trials have shown that high-dose statin (HDS) treatment could reduce vascular events. In high-risk populations, lipid treatment guidelines have generally suggested prescribing statin up to the highest recommended dosage. However, there remains concern about the risk of intracerebral hemorrhage (ICH) with HDS treatment. METHODS: This was a national population-based cohort study from the National Health Insurance Research Database of Taiwan extending from July 2001 to December 2008. Patients with cerebrovascular or cardiovascular disease were enrolled. The HDS group was defined as those patients receiving more than 420 mg per year of atorvastatin or an equivalent potency statin. Moderate dose statin group (MDS) was defined as those patients receiving atorvastatin in amounts between 196-420 mg per year or an equivalent potency statin. Low dose statin (LDS) group was defined as those receiving less than 196 mg per year of atorvastatin or an equivalent statin. The primary endpoint is ICH. The secondary endpoints are myocardial infarction (MI), ischemic stroke (IS) and new-onset DM (NDM). RESULTS: A total of 5459 patients were enrolled in our study, with study participant ages ranging from 62.91 ± 11.85 years and a mean follow-up time of 2039 ± 6 days. After adjusting for age, gender, diabetes and hypertension, Cox regression analysis found ICH risk was lower in HDS and MDS groups compared with LDS (HR 0.49, 95% CI 0.26-0.91, p = 0.0246 and HR 0.45, 95% CI 0.24-0.86, p = 0.0157). The risk of IS is lower in patients with HDS treatment (HR 0.68, 95% CI 0.55-0.83, p < 0.01). However, the risk of MI and NDM incidence are not statistically significant between the different dose groups. CONCLUSIONS: In the real-world data provided by Taiwan's National Health Insurance research database, it was shown that patients who received a higher dose of statin had a reduced and not elevated risk of intracerebral hemorrhage. KEY WORDS: High-dose statin; Hyperlipidemia; Intracerebral hemorrhage; Ischemic stroke; New-onset DM.

Association of Single Nucleotide Polymorphisms with Atrial Fibrillation and the Outcome after Catheter Ablation.

BACKGROUND: The association of gene variants with atrial fibrillation (AF) type and the recurrence of AF after catheter ablation in Taiwan is still unclear. In this study, we aimed to investigate the relationships between gene variants, AF type, and the recurrence of AF. METHODS: In our investigation, we examined 383 consecutive patients with AF (61.9 ± 14.0 years; 63% men); of these 383 patients, 189 underwent catheter ablation for drug-refractory AF. Thereafter, the single nucleotide polymorphisms rs2200733, and rs7193343 were genotyped using real-time polymerase chain reaction. RESULTS: The rs7193343 variant was independently associated with non-paroxysmal AF (non-PAF). In the PAF group, the rs7193343 variant was independently associated with AF recurrence after catheter ablation. However, the rs2200733 variant was not associated with AF recurrence in this group. The combination of the rs7193343 and rs2200733 risk alleles was associated with a better predictive power in the PAF patients. In contrast, in the non-PAF group, the SNPs were not associated with recurrence. The rs7193343 and rs2200733 variants were not associated with different atrial voltage and activation times. CONCLUSIONS: The rs7193343 variants were associated with AF recurrence after catheter ablation in PAF patients but not in non-PAF patients. The rs7193343 CC variant was independently associated with non-PAF.

Acute reversal of phospholamban inhibition facilitates the rhythmic whole-cell propagating calcium waves in isolated ventricular myocytes.

Phospholamban (PLB) inhibits the activity of cardiac sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA2a). Phosphorylation of PLB during sympathetic activation reverses SERCA2a inhibition, increasing SR Ca(2+) uptake. However, sympathetic activation also modulates multiple other intracellular targets in ventricular myocytes (VMs), making it impossible to determine the specific effects of the reversal of PLB inhibition on the spontaneous SR Ca(2+) release. Therefore, it remains unclear how PLB regulates rhythmic activity in VMs. Here, we used the Fab fragment of 2D12, a monoclonal anti-PLB antibody, to test how acute reversal of PLB inhibition affects the spontaneous SR Ca(2+) release in normal VMs. Ca(2+) sparks and spontaneous Ca(2+) waves (SCWs) were recorded in the line-scan mode of confocal microscopy using the Ca(2+) fluorescent dye Fluo-4 in isolated permeabilized mouse VMs. Fab, which reverses PLB inhibition, significantly increased the frequency, amplitude, and spatial/temporal spread of Ca(2+) sparks in VMs exposed to 50 nM free [Ca(2+)]. At physiological diastolic free [Ca(2+)] (100-200 nM), Fab facilitated the formation of whole-cell propagating SCWs. At higher free [Ca(2+)], Fab increased the frequency and velocity, but decreased the decay time of the SCWs. cAMP had little additional effect on the frequency or morphology of Ca(2+) sparks or SCWs after Fab addition. These findings were complemented by computer simulations. In conclusion, acute reversal of PLB inhibition alone significantly increased the spontaneous SR Ca(2+) release, leading to the facilitation and organization of whole-cell propagating SCWs in normal VMs. PLB thus plays a key role in subcellular Ca(2+) dynamics and rhythmic activity of VMs.