Repetition of Paclitaxel-Coated Devices for the Treatment of Lower Extremity Artery Disease: Mortality Outcomes and Predictors.

Background: A recent meta-analysis reported late excess mortality in patients treated with paclitaxel-coated devices (PCDs) for symptomatic femoropopliteal disease. However, this finding is controversial. Objectives: To investigate the impact on mortality and predictors of repeat exposure to PCDs in patients with lower extremity peripheral arterial disease (LE-PAD). Methods: We analyzed registry patient-level data from two centers. A total of 214 patients were enrolled, and stratified based on terciles of cumulative dose of paclitaxel. We treated 134 patients with a single PCD exposure and 80 with multiple PCD exposures. We used the follow-up index (FUI) in Kaplan-Meier survival estimates to minimize potential selection bias. We used Cox proportional hazard and splines models to determine the predictors of mortality and assess their relationships with mortality. Results: The mean cumulative dose of paclitaxel was significantly different among groups (6.40 mg vs. 15.06 mg vs. 38.57 mg, p < 0.001). The 5-year FUI (0.93 ± 0.19 vs. 0.94 ± 0.18 vs. 0.95 ± 0.15, p = 0.836) and survival rates were not different (65.4% vs. 51.9% vs. 72.0%, p = 0.148). There was no dose-response association between paclitaxel dosage and death (p = 0.297). The predictors of death were congestive heart failure, stroke, dialysis dependence, neutrophil-lymphocyte ratio (NLR) > 3, age > 71 years, and body mass index (BMI) < 20 kg/m2. Spline model analysis validated the non-linear associations between mortality, age, BMI, and NLR. Conclusions: Repeated PCD exposure for LE-PAD did not result in excess late mortality. Predictors of mortality might change over time, and continuous variables had non-linear relationships with death.

Combined corrected QT interval and growth differentiation factor-15 level has synergistic predictive value for long-term outcome of angiographically confirmed coronary artery disease.

BACKGROUND: The corrected QT interval (QTc) predicts prognosis for the general population and patients with coronary artery disease (CAD). Growth differentiation factor-15 (GDF-15) is a biomarker of myocardial fibrosis and left ventricular (LV) remodelling. The interaction between these two parameters is unknown. SUBJECTS AND METHODS: This study included 487 patients with angiographically confirmed CAD. QTc was calculated using the Bazett formula. Multiple biochemistries and GDF-15 levels were measured. The primary endpoint was total mortality, and the secondary endpoints comprised the combination of total mortality, myocardial infarction and hospitalisation for heart failure and stroke. RESULTS: The mean follow-up period was 1029 ± 343 days (5-1692 days), during which 21 patients died and 47 had secondary endpoints. ROC curve analysis for the optimal cut-off value of primary endpoint is 1.12 ng/mL for GDF-15 (AUC = 0.787, P = 9.0 × 10-6 ) and 438.5 msec for QTc (AUC = 0.698, P = .002). Utilising linear regression, QTc has a positive correlation with Log-GDF-15 (r = .216, P = 1.0 × 10-6 ). Utilising Kaplan-Meier analysis, both QTc interval and GDF-15 level are significant predictors for primary end point (P = .000194, P = 2.0 × 10-6 , respectively) and secondary endpoint (P = .00028, P = 6.15 × 10-8 , respectively). When combined these two parameters together, a significant synergistic predictive power was noted for primary and secondary endpoint (P = 2.31 × 10-7 , P = 1.26 × 10-8 , respectively). This combined strategy also showed significant correlation with the severity of CAD (P < .001). CONCLUSION: In Chinese patient with angiographically confirmed CAD, a combined strategy utilising an ECG parameter (QTc) and a circulating biomarker (GDF-15) has good correlation with the severity of CAD, and improves the predictive power for total mortality.

90% Accuracy for Photoplethysmography-Based Non-Invasive Blood Glucose Prediction by Deep Learning with Cohort Arrangement and Quarterly Measured HbA1c.

Previously published photoplethysmography-(PPG) based non-invasive blood glucose (NIBG) measurements have not yet been validated over 500 subjects. As illustrated in this work, we increased the number subjects recruited to 2538 and found that the prediction accuracy (the ratio in zone A of Clarke's error grid) reduced to undesirable 60.6%. We suspect the low prediction accuracy induced by larger sample size might arise from the physiological diversity of subjects, and one possibility is that the diversity might originate from medication. Therefore, we split the subjects into two cohorts for deep learning: with and without medication (1682 and 856 recruited subjects, respectively). In comparison, the cohort training for subjects without any medication had approximately 30% higher prediction accuracy over the cohort training for those with medication. Furthermore, by adding quarterly (every 3 months) measured glycohemoglobin (HbA1c), we were able to significantly boost the prediction accuracy by approximately 10%. For subjects without medication, the best performing model with quarterly measured HbA1c achieved 94.3% prediction accuracy, RMSE of 12.4 mg/dL, MAE of 8.9 mg/dL, and MAPE of 0.08, which demonstrates a very promising solution for NIBG prediction via deep learning. Regarding subjects with medication, a personalized model could be a viable means of further investigation.

Shorter Leukocyte Telomere Length Is Associated With Atrial Remodeling and Predicts Recurrence in Younger Patients With Paroxysmal Atrial Fibrillation After Radiofrequency Ablation.

BACKGROUND: Telomere length is a biologic aging marker. This study investigated leukocyte telomere length (LTL) as a new biomarker to predict recurrence after paroxysmal atrial fibrillation (PAF) ablation.Methods and Results:A total of 131 participants (26 healthy individuals and 105 symptomatic PAF patients) were enrolled. PAF patients (54.1±10.8 years) who received catheter ablation therapy were divided into 2 groups: recurrent AF (n=25) and no recurrent AF after catheter ablation (n=80). Peripheral blood mononuclear cells were collected from all subjects to measure LTL. Under 50 years old, LTL in healthy individuals (n=17) was longer than in PAF patients (n=31; 7.34±0.58 kbp vs. 6.44±0.91 kbp, P=0.01). In PAF patients, LTL was positively correlated with left atrial bipolar voltage (R=0.497, P<0.001), and negatively correlated with biatrial scar area (R=-0.570, P<0.001) and left atrial diameter (R=-0.214, P=0.028). LTL was shorter in the patients with recurrent AF than in those without recurrent AF after catheter ablation (5.68±0.82 kbp vs. 6.66±0.71 kbp; P<0.001). On receiver operating characteristic curve analysis, LTL cut-off <6.14 kbp had a specificity of 0.68 and sensitivity of 0.79 to predict recurrent AF after catheter ablation. CONCLUSIONS: Young PAF patients (≤50 years) had shorter LTL. Shorter LTL was associated with a degenerative atrial substrate and recurrence after catheter ablation in younger PAF patients.

Early detection of electromechanical dysfunction in patients with idiopathic premature ventricular contractions.

BACKGROUND: Premature ventricular contractions (PVCs) induced by subtle cardiac dysfunction are missed by echocardiography. We evaluated acoustic cardiography for detection of early electromechanical dysfunction in patients with idiopathic PVCs and normal left ventricular ejection fraction (LVEF), and investigated the impact of radiofrequency ablation (RFA) in reversing this adverse effect. METHODS: Eighty-six patients with PVCs and 33 normal controls having normal LVEF were studied. Fifty PVC patients were in the ablation group and 36 in the nonablation group. %Electromechanical activation time (%EMAT), %left ventricular systolic time (%LVST), third (S3) and fourth heart sound (S4), and systolic dysfunction index (SDI) during sinus rhythm (SR) were measured by acoustic cardiography (Audicor, Inovise Medical, Inc., Beaverton, OR, USA) pre- and postablation. In 28 patients, acoustic parameters were compared during SR without PVCs, and SR with single PVC, ≥ 2 PVCs, or ventricular tachycardia over 10-second Audicor recording in a single patient at different times. Twenty-four-hour acoustic cardiographic and acoustic cardiographic Holter recording were used to assess the impact of PVC burden on electromechanical function in 41 patients. RESULTS: %EMAT, S3, S4, and SDI showed significant worsening in the PVC versus control group. %EMAT and SDI were worsened with increasing PVC number in a 10-second strip. %EMAT showed significant linear increment with increasing PVC burden. There was a significant improvement in %EMAT, %LVST, S3, S4, and SDI postablation in patients with PVCs. CONCLUSION: Acoustic cardiography can detect PVC-induced minor electromechanical dysfunction in patients with normal LVEF. RFA can reverse this adverse effect.

A Novel and Simple Algorithm Using Surface Electrocardiogram That Localizes Accessory Conduction Pathway in Wolff-Parkinson-White Syndrome in Pediatric Patients.

BACKGROUND: The location of the accessory pathway (AP) can be precisely identified on surface electrocardiography (ECG) in adults with Wolff-Parkinson-White (WPW) syndrome. However, current algorithms to locate the AP in pediatric patients with WPW syndrome are limited. OBJECTIVE: To propose an optimal algorithm that localizes the AP in pediatric patients with WPW syndrome. METHODS: From 1992 to 2016, 180 consecutive patients aged below 18 years with symptomatic WPW syndrome were included. After the exclusion of patients with non-descriptive electrocardiography (ECG), multiple APs, congenital heart diseases, non-inducible tachycardia, and those who received a second ablation, 104 patients were analyzed retrospectively. Surface ECG was obtained before ablation and evaluated by using previously documented algorithms, from which a new pediatric algorithm was developed. RESULTS: Previous algorithms were not highly accurate when used in pediatric patients with WPW syndrome. In the new algorithm, the R/S ratio of V1 and the polarity of the delta wave in lead I could distinguish right from the left side AP with 100% accuracy. The polarity of the delta wave of lead V1 could distinguish free wall AP from septal AP with an accuracy of 100% in left-side AP, compared to 88.6% in leads III and V1 for right-side AP. The overall accuracy was 92.3%. CONCLUSIONS: This simple, novel algorithm could differentiate left from right AP and septal from free wall AP in pediatric patients with WPW syndrome.

Electrocardiographic features of failed and recurrent right ventricular outflow tract catheter ablation of idiopathic ventricular arrhythmias.

INTRODUCTION: Various ECG algorithms have been proposed to identify the origin of idiopathic outflow tract (OT)-ventricular arrhythmia (VA). However, electrocardiographic features of failed and recurrent right ventricular outflow tract (RVOT) ablation of idiopathic OT-VAs have not been clearly elucidated. METHODS AND RESULTS: A total of 264 consecutive patients (mean age: 44.0 ± 13.0 years, 96 male) undergoing RVOT ablation for OT-VAs with a transition ≥V3 , including 241 patients (91.6%) with initially successful procedures and 23 patients (8.4%) with failed ablation. Detailed clinical characteristics and ECG features were analyzed and compared between the two groups. VAs with failed RVOT ablation had larger peak deflection index (PDI), longer V2 R wave duration (V2 Rd), smaller V2 S wave amplitude, higher R/S ratio in V2 , higher V3 R wave amplitude, and larger V2 transition ratio than those with successful ablation. Multivariate analysis demonstrated that PDI, V2 Rd, V2 transition ratio, and pacemapping score acquired during mapping independently predicted failed ablation (P  =  0.01, P  =  0.01, P  =  0.01, and P < 0.001, respectively). In 31 recurrent cases (12.8%) after initially successful ablation, multivariate Cox regression analysis showed that only the earliest activation time acquired during mapping predicted the recurrences after successful ablation (P  =  0.001). The recurrent cases displayed different ECG features comparing with those with failed ablation. CONCLUSION: The electrocardiographic features of failed RVOT ablation of idiopathic OT-VAs with a transition ≥V3 were characterized by PDI, V2 Rd, V2 transition ratio, and pacemapping score acquired during mapping, unlike the recurrent RVOT ablation.

Novel electrophysiological criteria for septal ventricular outflow tract tachycardias requiring a sequential bilateral ablation.

BACKGROUND: Septal ventricular outflow tract ventricular arrhythmias (OT-VAs) are defined as septal origin VAs from the right ventricular or left ventricular OT. Patients with septal OT-VAs may require a sequential bilateral OT ablation. This study aimed to evaluate the electrophysiological characteristics and ablation outcome in patients with septal OT-VAs. METHODS: We retrospectively analyzed the electrocardiography and electrophysiological parameters in 96 patients (mean age 49 ± 15 years, 49 male) undergoing bilateral activation mapping before catheter ablation of idiopathic septal OT-VAs. The patients were categorized into three groups based on the successful ablation sites, including the right ventricular outflow tract (RVOT), RVOT/left ventricular outflow tract (LVOT), and LVOT. RESULTS: Mapping in the three groups demonstrated a gradually decreasing and increasing trend in the earliest activation time obtained from the RVOT and LVOT, respectively. The absolute earliest activation time discrepancy (AEAD) of ≤18 milliseconds could predict the requirement for a sequential bilateral ablation with a sensitivity and specificity of 100.0% and 93.7%, respectively. The small AEAD (≤21 milliseconds) was associated with a higher recurrence rate in patients receiving a successful unilateral ablation, while patients with a longer distance between the bilateral OT earliest activation sites (DEA > 26 mm) increased future recurrences after an initially successful sequential bilateral ablation. CONCLUSIONS: The application of bilateral OT-VA activation mapping and the measurement of the AEAD and DEA provided not only pivotal information for the ablation strategy, but also prognostic implications for recurrences in patients with septal OT-VAs.

Circulating microRNAs in arrhythmogenic right ventricular cardiomyopathy with ventricular arrhythmia.

Aims: MicroRNAs (miRNAs) have been implicated in cardiac diseases. This study aimed to characterize the circulating miRNAs in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and correlate the miRNAs with the clinical outcomes of ARVC. Methods and results: This study included 62 patients with ventricular arrhythmia (VA): 28 patients (45%) had definite ARVC, 11 (18%) had borderline or possible ARVC, and 23 (37%) had idiopathic ventricular tachycardia (VT). In addition, 33 age- and sex-matched healthy subjects were enrolled as normal control subjects. The expression of selected miRNAs was analysed in all study subjects. The clinical outcomes of patients with definite ARVC after catheter ablation were further investigated. On the basis of the miRNA polymerase chain reaction array, we selected 11 miRNAs for analysis of their expression in the plasma of all subjects. Definite ARVC patients had significantly higher expression of circulating miR-144-3p, 145-5p, 185-5p, and 494 than the three other groups. Out of 25 definite ARVC patients who underwent radiofrequency catheter ablation, recurrent VA occurred in 8 patients (32%) during the follow-up period (45 ± 20 months). Definite ARVC patients with recurrent VA had a higher level of circulating miR-494 than did those without recurrence. Receiver operating characteristic analysis showed miR-494 to be a predictive factor of recurrent VA (area under the curve: 0.832). Conclusion: Plasma levels of miR-144-3p, 145-5p, 185-5p, and 494 were significantly elevated in definite ARVC patients with VA. An increased plasma level of miR-494 was associated with the recurrence of VA after ablation in definite ARVC patients.

Heterogeneous distribution of substrates between the endocardium and epicardium promotes ventricular fibrillation in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Aims: Whether the distribution of scar in arrhythmogenic right ventricular cardiomyopathy (ARVC) plays a role in predicting different types of ventricular arrhythmias is unknown. This study aimed to investigate the prognostic value of scar distribution in patients with ARVC. Methods and results: We studied 80 consecutive ARVC patients (46 men, mean age 47 ± 15 years) who underwent an electrophysiological study with ablation. Thirty-four patients receive both endocardial and epicardial mapping. Abnormal endocardial substrates and epicardial substrates were characterized. Three groups were defined according to the epicardial and endocardial scar gradient (<10%: transmural, 10-20%: intermediate, >20%: horizontal, as groups 1, 2, and 3, respectively). Sinus rhythm electrograms underwent a Hilbert-Huang spectral analysis and were displayed as 3D Simultaneous Amplitude Frequency Electrogram Transformation (SAFE-T) maps, which represented the arrhythmogenic potentials. The baseline characteristics were similar between the three groups. Group 3 patients had a higher incidence of fatal ventricular arrhythmias requiring defibrillation and cardiac arrest during the initial presentation despite having fewer premature ventricular complexes. A larger area of arrhythmogenic potentials in the epicardium was observed in patients with horizontal scar. The epicardial-endocardial scar gradient was independently associated with the occurrence of fatal ventricular arrhythmias after a multivariate adjustment. The total, ventricular tachycardia, and VF recurrent rates were higher in Group 3 during 38 ± 21 months of follow-up. Conclusion: For ARVC, the epicardial substrate that extended in the horizontal plane rather than transmurally provided the arrhythmogenic substrate for a fatal ventricular arrhythmia circuit.

A novel depth estimation algorithm of chest compression for feedback of high-quality cardiopulmonary resuscitation based on a smartwatch.

INTRODUCTION: High-quality cardiopulmonary resuscitation (CPR) is a key factor affecting cardiac arrest survival. Accurate monitoring and real-time feedback are emphasized to improve CPR quality. The purpose of this study was to develop and validate a novel depth estimation algorithm based on a smartwatch equipped with a built-in accelerometer for feedback instructions during CPR. METHODS: For data collection and model building, researchers wore an Android Wear smartwatch and performed chest compression-only CPR on a Resusci Anne QCPR training manikin. We developed an algorithm based on the assumptions that (1) maximal acceleration measured by the smartwatch accelerometer and the chest compression depth (CCD) are positively correlated and (2) the magnitude of acceleration at a specific time point and interval is correlated with its neighboring points. We defined a statistic value M as a function of time and the magnitude of maximal acceleration. We labeled and processed collected data and determined the relationship between M value, compression rate and CCD. We built a model accordingly, and developed a smartwatch app capable of detecting CCD. For validation, researchers wore a smartwatch with the preinstalled app and performed chest compression-only CPR on the manikin at target sessions. We compared the CCD results given by the smartwatch and the reference using the Wilcoxon Signed Rank Test (WSRT), and used Bland-Altman (BA) analysis to assess the agreement between the two methods. RESULTS: We analyzed a total of 3978 compressions that covered the target rate of 80-140/min and CCD of 4-7 cm. WSRT showed that there was no significant difference between the two methods (P = 0.084). By BA analysis the mean of differences was 0.003 and the bias between the two methods was not significant (95% CI: -0.079 to 0.085). CONCLUSION: Our study indicates that the algorithm developed for estimating CCD based on a smartwatch with a built-in accelerometer is promising. Further studies will be conducted to evaluate its application for CPR training and clinical practice.

Safety and Efficacy of Epicardial Ablation of Ventricular Tachyarrhythmias: Experience from a Tertiary Referral Center in Taiwan.

BACKGROUND: Epicardial catheter ablation has been shown to be an effective strategy for treating ventricular arrhythmias (VA). We investigated the efficacy and safety from a tertiary referral center in Taiwan. METHODS: From 2010 to 2016, patients undergoing epicardial ablation for VAs were consecutively enrolled. The clinical characteristics, disease entity, electrophysiological studies, and ablation outcome were extracted for further analysis. RESULTS: A total of 80 patients were eligible, including 34 patients for arrhythmogenic right ventricular cardiomyopathy (ARVC), 16 for Brugada syndrome (BrS), 13 for idiopathic VAs, 11 for idiopathic dilated cardiomyopathy (IDCM), 2 for ischemic cardiomyopathy, and 4 for other nonischemic cardiomyopathies (NICM). Epicardial ablation rendering VAs non-inducible was achieved in 78 patients (97.5%). There were no procedure-related deaths. Major complications were reported in 8 (10.0%) patients, including an acute hemopericardium in 5 (6.3%), delayed tamponade in 1 (1.3%), hemothorax in 1 (1.3%), and major pericardial reaction in 1 (1.3%). Two (2.7%) patients died due to causes other than procedure-related deaths. After a mean follow-up of 31 ± 15 months, 20 patients (25.0%) presented with VA recurrences, including 13 with ARVC, 1 with BrS, 1 with idiopathic VAs, 4 with IDCM, and 1 with other NICM. CONCLUSIONS: In this tertiary referral center's experience, the complication rate of an epicardial approach was acceptable. Patients with NICM displayed a growing trend for a referral for epicardial ablation. The long-term follow-up demonstrated that an epicardial ablation for idiopathic VAs and BrS was associated with a better prognosis than that for the other etiologies.

Risk of Stroke in Patients With Short-Run Atrial Tachyarrhythmia.

BACKGROUND AND PURPOSE: The risk of stroke in patients with short-run atrial tachyarrhythmia (AT) remains unclear. This study aimed to investigate the relationship between short-run AT and the stroke and the use of the CHA2DS2-VASc score for the risk stratification. METHODS: From the registry of 24-hour Holter monitoring, 5342 subjects without known atrial fibrillation or stroke were enrolled. Short-run AT was defined as episodes of supraventricular ectopic beats <5 seconds. RESULTS: There were 1595 subjects (29.8%) with short-run AT. During the median follow-up period of 9.0 years, 494 subjects developed new-onset stroke. Patients with short-run AT had significantly higher stroke rates compared with patients without short-run AT (11.4% versus 8.3%; P<0.001). In patients with short-run AT, the number of strokes per 100 person-years for patients with CHA2DS2-VASc score of 0 and 1 were 0.23 and 0.67, respectively. However, the number of them for patients with CHA2DS2-VASc score of 2, 3, 4, and ≥5 were 1.62, 1.89, 1.30, and 2.91, respectively. In patients with CHA2DS2-VASc score of 0 or 1, age (>61 years old) and burden of premature atrial contractions (>25 beats/d) independently predicted the risk of stroke. In subgroup analyses, short-run AT patients were divided into 3 groups based on their CHA2DS2-VASc scores: low score (score of 0 [men] or 1 [women]; n=324), intermediate score (score of 1 [men] or 2 [women]; n=275), and high score (score of ≥2 [men] or ≥3 [women]; n=996). When compared with low score, intermediate and high scores were independent predictors for stroke (hazard ratio, 6.165; P<0.001 and hazard ratio, 8.577; P<0.001, respectively). CONCLUSIONS: Short-run AT increases the risk of stroke. Therefore, the CHA2DS2-VASc score could be used for the risk stratification. Age and burden of premature atrial contractions were independent predictors for stroke in patients with CHA2DS2-VASc score of 0 or 1.

Left Atrial Size and Left Ventricular End-Systolic Dimension Predict the Progression of Paroxysmal Atrial Fibrillation After Catheter Ablation.

INTRODUCTION: Although rare, some paroxysmal atrial fibrillations (AF) still progress despite radiofrequency (RF) ablation. In the study, we evaluated the long-term efficacy of RF ablation and the predictors of AF progression. METHODS: A total of 589 paroxysmal AF patients (404 men and 185 women; aged 54 ± 12 years) who received 3-dimensional mapping and ablation were enrolled. Their clinical parameters and electrophysiological characteristics were collected. They were divided into Group 1 (N = 13, with AF progression) and Group 2 (N = 576, no AF progression). AF progression was defined as recurrence of persistent AF. RESULTS: Group 1 patients had larger left atrial (LA) diameter, larger left ventricle (LV) end-systolic and end-diastolic diameters, poorer LV systolic function, and more amiodarone use at baseline. After 1.2 ± 0.5 procedures, 123 (21%) patients experienced recurrence during 56 ± 29 months' follow-up. In the multivariate analysis, LA diameter (P = 0.018, HR = 1.12, 95% CI = 1.02-1.24) and LV end-systolic diameter (P = 0.005, HR = 1.10, 95% CI = 1.03-1.17) independently predicted AF progression. LA diameter >43 mm and LV end-systolic diameter >31 mm were the best cut-off values for predicting AF progression by ROC analysis. AF progression rate achieved 19% if they had both larger LA diameter (>43 mm) and LV end-systolic diameter (>31 mm). CONCLUSION: RF ablation prevents the progression of paroxysmal AF effectively, except in patients with increased LA diameter and LV end-systolic diameter on echocardiogram, suggesting more aggressive rhythm control therapies should be considered in these patients.

Atrial fibrillation originating from superior vena cava with atrial flutter-electrocardiogram pattern.

BACKGROUNDS: Substrate property is related to the genesis and maintenance of atrial fibrillation (AF). The aim of the study was to investigate the impact of substrate property on the electrocardiogram (ECG) in patients with AF originating from the superior vena cava (SVC). METHODS AND RESULTS: Seventy-six patients with AF originating from SVC who underwent catheter ablation were included from 2004 to 2013. Of these patients, 16 had a presentation of atrial flutter (AFL)-pattern ECG during AF (group 1), and 60 patients did not (group 2). There was no significant difference in clinical characteristics between the groups. The percentage of low voltage zone (LVZ) in SVC below the level of pulmonary artery in group 1 was significantly larger than that in group 2. The polarities of the flutter wave in 12-lead ECG were compared with another 26 subjects with reverse typical AFL. The ECG morphology was characterized by negative or biphasic P waves in lead V1 in most of the patients in group 1 (62.5%), which was analogous to that in reverse typical AFL. The negative polarity of flutter waves in aVL might distinguish SVC AF with an AFL-pattern from reverse typical AFL. CONCLUSION: The ECG characteristics of AF originating from SVC can mimic atypical AFL. LVZ in the SVC may be associated with the presentation of AFL-pattern ECG.

The roles of alcohol dehydrogenase in patients with atrial fibrillation.

BACKGROUND: Alcohol consumption is known to increase the risk of atrial fibrillation (AF). Whether the genotypes of alcohol-metabolizing genes (alcohol dehydrogenase [ADH1B]) are associated with the risk of AF recurrence after catheter ablation remains unclear. METHODS AND RESULTS: The ADH1B genotypes of 281 patients who received catheter ablation for AF were examined. We followed this group of patients to monitor their AF recurrence. Alcohol consumption levels of this cohort were evaluated before and after catheter ablation. There was no difference in the underlying diseases presented by the patients with different ADH1B genotypes. Regardless of the ADH1B genotypes, the amount of alcohol consumption was the only factor associated with left atrial dilatation. The ADH1B*2 alleles (hazard ratio: ADH1B*1/*2 vs *1/*1: 2.64; ADH1B*2/*2 vs *1/*1: 1.80, P = 0.02) and the levels of alcohol consumption were independently associated with AF recurrence in the patients with paroxysmal AF after catheter ablation. ADH1B polymorphisms were not associated with AF recurrence in the patients with nonparoxysmal AF. We also found that the association of increased AF recurrence with alcohol consumption and the ADH1B genotypes cannot be explained by mechanisms of systemic inflammation. CONCLUSIONS: ADH1B*2/*2 genotype and amount of alcohol consumption increase the risk of AF recurrence after catheter ablation.

Novel electrophysiological characteristics of atrioventricular nodal continuous conduction curves in atrioventricular nodal re-entrant tachycardia with concomitant cavotricuspid isthmus-dependent atrial flutter.

AIMS: The detailed electrophysiological characteristics of patients with both atrioventricular nodal re-entrant tachycardia (AVNRT) and atrial flutter (AFL) have not been clarified. This study investigated the related electrophysiological differences in a large series of patients undergoing radiofrequency catheter ablation of AVNRT. METHODS AND RESULTS: A total of 1063 clinically documented AVNRT patients underwent catheter ablation were enrolled. Before the slow pathway (SP) ablation, 61 patients (5.7%) had inducible sustained cavotricuspid isthmus (CTI)-dependent AFL (Group 1), and the others (94.3%) without inducible sustained CTI-dependent AFL were defined as Group 2. The electrophysiological characteristics of these two groups and effect of the SP ablation on the inducibility of AFL were assessed. In Group 1, 36 patients (59%) had inducible/sustained AFL after the ablation of AVNRT and required a CTI ablation. The Group 1 patients had more AVNRT with continuous atrioventricular (AV) node function curves (P < 0.001, odds ratio = 7.55 [3.70-16.7], multivariate regression), and a younger age (P = 0.02, odds ratio = 1.02 [1.003-1.03], multivariate regression) than Group 2. The other characteristics were comparable between the two groups. The long-term follow-up (64.9 ± 34.9 months) revealed that the recurrence of AFL/atrial fibrillation was similar between the two groups (P > 0.05). CONCLUSION: Atrioventricular nodal re-entrant tachycardia patients with concomitant CTI-dependent AFL had more continuous AV node function curves. Forty-one per cent of these patients had non-inducible AFL after the SP ablation, indicating a slow conduction isthmus in the triangle of Koch area.

The Effect of Tai Chi Chuan on Obstacle Crossing Strategy in Older Adults.

The purpose of this study was to determine the effect of Tai Chi Chuan on the strategies of obstacle-crossing behavior in older adults aged over 65 years. Fifteen Tai Chi group (TCG) participants were compared with 15 general group (GG) participants. Kinematic parameters (by Vicon motion analysis system) and ground reaction forces (by Kistler force plates) were synchronously recorded. A two-way mixed-design ANOVA (α = 0.05) was used to test the effects of the group and the obstacle height. The TCG performed significantly faster stride velocities, longer stride lengths, and shorter stride times than GG while crossing the obstacles. TCG could also produce significantly larger forward ground reaction forces to propel the body and were able to make a significantly greater flexion angle of the hip of the leading leg compared with the GG. It was concluded that the TCG adopted a different strategy with GG to cross the obstacles and completed the crossing behavior more effectively.

Ground reaction force characteristics of Tai Chi push hand.

Push Hand is an advanced training technique for the Yang-style old frame 108 forms Tai Chi Chuan. It is performed by two practitioners. To clarify how people use forces during Push Hand training, it is important to review the ground reaction force (GRF). Here, we quantify the characteristics of the GRF during Push Hand training. Kinematic data and GRF data from 10 Tai Chi Chuan practitioners (29.9 ± 7.87 years) were synchronously recorded using a three-dimensional motion analysis system (200 frames · s(-1)) and three-dimensional force plates (1000 Hz). The resultant GRF for both feet for the 0%, 50% and 100% phases of attack and defence were compared to body weight using a paired-samples t-test. The differences in the resultant GRF between the 0%, 50% and 100% phases of attack and defence were tested by one-way repeated-measures ANOVA. The significance level was set to 0.05. The total resultant GRF was almost equal to the participant's body weight in push hand. This result was consistent throughout the entire push hand process. Our results revealed that the GRF was comparable to the body weight, implying that practitioners do not push or resist their opponents during the push hand process.

Implicit HbA1c Achieving 87% Accuracy within 90 Days in Non-Invasive Fasting Blood Glucose Measurements Using Photoplethysmography.

To reduce the error induced by overfitting or underfitting in predicting non-invasive fasting blood glucose (NIBG) levels using photoplethysmography (PPG) data alone, we previously demonstrated that incorporating HbA1c led to a notable 10% improvement in NIBG prediction accuracy (the ratio in zone A of Clarke's error grid). However, this enhancement came at the cost of requiring an additional HbA1c measurement, thus being unfriendly to users. In this study, the enhanced HbA1c NIBG deep learning model (blood glucose level predicted from PPG and HbA1c) was trained with 1494 measurements, and we replaced the HbA1c measurement (explicit HbA1c) with "implicit HbA1c" which is reversely derived from pretested PPG and finger-pricked blood glucose levels. The implicit HbA1c is then evaluated across intervals up to 90 days since the pretest, achieving an impressive 87% accuracy, while the remaining 13% falls near the CEG zone A boundary. The implicit HbA1c approach exhibits a remarkable 16% improvement over the explicit HbA1c method by covering personal correction items automatically. This improvement not only refines the accuracy of the model but also enhances the practicality of the previously proposed model that relied on an HbA1c input. The nonparametric Wilcoxon paired test conducted on the percentage error of implicit and explicit HbA1c prediction results reveals a substantial difference, with a p-value of 2.75 × 10-7.