Relationship between stress hyperglycemia ratio and acute kidney injury in patients with congestive heart failure.

BACKGROUND: The stress hyperglycemia ratio (SHR) has been demonstrated as an independent risk factor for acute kidney injury (AKI) in certain populations. However, this relationship in patients with congestive heart failure (CHF) remains unclear. Our study sought to elucidate the relationship between SHR and AKI in patients with CHF. METHODS: A total of 8268 patients with CHF were included in this study. We categorized SHR into distinct groups and evaluated its association with mortality through logistic or Cox regression analyses. Additionally, we applied the restricted cubic spline (RCS) analysis to explore the relationship between SHR as a continuous variable and the occurrence of AKI. The primary outcome of interest in this investigation was the incidence of AKI during hospitalization. RESULTS: Within this patient cohort, a total of 5,221 (63.1%) patients experienced AKI during their hospital stay. Upon adjusting for potential confounding variables, we identified a U-shaped correlation between SHR and the occurrence of AKI, with an inflection point at 0.98. When the SHR exceeded 0.98, for each standard deviation (SD) increase, the risk of AKI was augmented by 1.32-fold (odds ratio [OR]: 1.32, 95% CI: 1.22 to 1.46). Conversely, when SHR was below 0.98, each SD decrease was associated with a pronounced increase in the risk of AKI. CONCLUSION: Our study reveals a U-shaped relationship between SHR and AKI in patients with CHF. Notably, we identified an inflection point at an SHR value of 0.98, signifying a critical threshold for evaluating AKI in this population.

Outcomes of catheter ablation in high-risk patients with Brugada syndrome refusing an implantable cardioverter defibrillator implantation.

AIMS: The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation. METHODS AND RESULTS: A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation-triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5-73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012). CONCLUSION: Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population.

Left atrial reservoir strain measurements derived from intracardiac echocardiography in patients with atrial fibrillation: comparison with transthoracic echocardiography.

BACKGROUND: Intracardiac echocardiography (ICE) provides accurate left atrial (LA) anatomical information in the procedure of atrial fibrillation (AF) ablation but lacks LA functional assessment. LA reservoir strain (LASr) is an excellent marker of LA reservoir function. This study aimed to assess the agreement between LASr derived from ICE and transthoracic echocardiography (TTE) in AF patients and analyze the reproducibility of LASr assessed by ICE combined with speckle tracking imaging. METHODS: This study prospectively enrolled 110 patients with a clinical diagnosis of AF who were ready for AF ablation, including 71 patients with paroxysmal AF and 39 with persistent AF. TTE and ICE examinations were performed on each individual before AF ablation. LASr measurements derived from ICE and TTE images were using dedicated LA-tracking software. Pearson correlation coefficients (r) and Bland-Altman plots were used to evaluate the agreement of LASr between the two modalities. Intraclass correlation coefficients (ICCs) were used to assess intra- and inter-observer reproducibility. RESULTS: The agreement between LASr obtained from ICE and TTE, especially between LASrLPV (LASr derived from LA left pulmonary vein view of ICE) and LASrTTE (LASr derived from TTE) were good in both paroxysmal and persistent AF patients [r = 0.890 (P < 0.001) for overall population; r = 0.815 (P < 0.001) and Bias ± LOA: -0.3 ± 9.9% for paroxysmal AF; r = 0.775 (P < 0.001) and Bias ± LOA: -2.6 ± 3.9% for persistent AF, respectively]. But the values of LASr derived from ICE were slightly lower than those of TTE, especially in patients with persistent AF. The ICCs for LASr derived from ICE were excellent (all ICCs > 0.90). CONCLUSIONS: In patients with AF, LASr derived from ICE demonstrated excellent reproducibility and showed good agreement with LASr obtained from TTE. Obtaining LASr from ICE images may be a supplementary method to evaluate LA reservoir function in AF patients and expands the potential of ICE in the field of cardiac function assessment.

Development and Validation of Machine Learning-Based Models to Predict In-Hospital Mortality in Life-Threatening Ventricular Arrhythmias: Retrospective Cohort Study.

BACKGROUND: Life-threatening ventricular arrhythmias (LTVAs) are main causes of sudden cardiac arrest and are highly associated with an increased risk of mortality. A prediction model that enables early identification of the high-risk individuals is still lacking. OBJECTIVE: We aimed to build machine learning (ML)-based models to predict in-hospital mortality in patients with LTVA. METHODS: A total of 3140 patients with LTVA were randomly divided into training (n=2512, 80%) and internal validation (n=628, 20%) sets. Moreover, data of 2851 patients from another database were collected as the external validation set. The primary output was the probability of in-hospital mortality. The discriminatory ability was evaluated by the area under the receiver operating characteristic curve (AUC). The prediction performances of 5 ML algorithms were compared with 2 conventional scoring systems, namely, the simplified acute physiology score (SAPS-II) and the logistic organ dysfunction system (LODS). RESULTS: The prediction performance of the 5 ML algorithms significantly outperformed the traditional models in predicting in-hospital mortality. CatBoost showed the highest AUC of 90.5% (95% CI 87.5%-93.5%), followed by LightGBM with an AUC of 90.1% (95% CI 86.8%-93.4%). Conversely, the predictive values of SAPS-II and LODS were unsatisfactory, with AUCs of 78.0% (95% CI 71.7%-84.3%) and 74.9% (95% CI 67.2%-82.6%), respectively. The superiority of ML-based models was also shown in the external validation set. CONCLUSIONS: ML-based models could improve the predictive values of in-hospital mortality prediction for patients with LTVA compared with traditional scoring systems.

Trimethylamine N-oxide is associated with coronary atherosclerotic burden in non-ST-segment myocardial infarction patients: SZ-NSTEMI prospective cohort study.

Trimethylamine N-oxide (TMAO) is reported to accelerate atherosclerosis and the development of adverse cardiac outcomes. Relationship between coronary atherosclerotic burden and TMAO has been examined in stable coronary artery disease and ST-segment elevation myocardial infarction, but not in non-ST-segment elevation myocardial infarction (NSTEMI). We examined the association between TMAO and coronary atherosclerotic burden in NSTEMI. In this prospective cohort study, two groups including NSTEMI (n = 73) and age-sex matched Healthy (n = 35) individuals were enrolled between 2019 and 2020. Coronary atherosclerotic burden was stratified based on the number of diseased coronary vessels and clinical risk scores including SYNTAX and GENSINI. Fasting plasma TMAO was measured by isotope dilution high-performance liquid chromatography. The median plasma TMAO levels were significantly higher in the NSTEMI group than in the Healthy group, respectively (0.59 µM; interquartile range [IQR]: 0.43-0.78 versus 0.42 µM; IQR: 0.33-0.64; P = 0.006). Within the NSTEMI group, higher TMAO levels were observed in the multivessel disease (MVD) versus single vessel disease (P = 0.002), and intermediate-high risk (score ≥ 23) versus low risk (score < 23) of SYNTAX (P = 0.003) and GENSINI (P = 0.005). TMAO level remained an independent predictor of MVD (odds ratio [OR]: 5.94, P = 0.005), intermediate-high risk SYNTAX (OR: 3.61, P = 0.013) and GENSINI scores (OR: 4.60, P = 0.008) following adjustment for traditional risk factors. Receiver operating characteristic curve (AUC) analysis for TMAO predicted MVD (AUC: 0.73, 95% confidence interval [Cl]: 0.60-0.86, P = 0.002), intermediate-high SYNTAX score (AUC: 0.70, 95% Cl: 0.58-0.82, P = 0.003) and GENSINI score (AUC: 0.70, 95% Cl: 0.57-0.83, P = 0.005). In all, TMAO levels are independently associated with high coronary atherosclerotic burden in NSTEMI.

Catheter ablation of arrhythmogenic right ventricular cardiomyopathy ventricular tachycardia: 18-year experience in 284 patients.

AIMS: The study aims to describe the long-term outcome of radiofrequency catheter ablation for ventricular tachycardia (VT) in a large cohort arrhythmogenic right ventricular cardiomyopathy (ARVC) patients. METHODS AND RESULTS: Radiofrequency catheter ablation was performed in 284 ARVC patients due to VT between July 2000 and January 2019. An endocardial approach was used initially, with epicardial ablation procedures reserved for those patients who failed an endocardial ablation. Activation, entrainment, pace and substrate mapping strategies were used with regional ablation applied. A total of 393 ablation procedures were performed including endocardial approach only (n = 377) and endo and epicardial combined (n = 16). Right ventricular basal free wall was accounted as the primary substrate of VT in 258 (65.6%) patients. There were 81 patients underwent redo ablation procedure (second time = 81; ≥3 times = 28). New targets were observed in 68.8% of redo procedures. There were 171 VT recurrences and 19 deaths occurred during the follow-up. Ventricular tachycardia-free survival rate of the first, second, and last ablation procedure was 56.7%, 73.2%, and 78.1%, respectively. Multivariate analysis showed ≥3 induced VTs in the procedure was correlated with rehospitalized VT recurrence [hazard ratio (HR) 1.467, 95% confidence interval (CI) 1.052-2.046; P = 0.024]. For all-cause mortality, rehospitalized VT and ≥3 induced VTs were the independent risk factors (HR 2.954, 95% CI 1.8068.038; P = 0.034; HR 3.189, 95% CI 1.073-9.482; P = 0.037). CONCLUSION: Endocardial ablation is effective to ARVC VT though it may require repeated procedures. Induced multiple VTs was correlated with worse outcomes.

A novel risk model for mortality and hospitalization following cardiac resynchronization therapy in patients with non-ischemic cardiomyopathy: the alpha-score.

BACKGROUND: Non-ischemic cardiomyopathy (NICM) has been associated with a better left ventricle reverse remodeling response and improved clinical outcomes after cardiac resynchronization therapy (CRT). The aims of our study were to identify the predictors of mortality and heart failure hospitalization in patients treated with CRT and design a risk score for prognosis. METHODS: A cohort of 422 consecutive NICM patients with CRT was retrospectively enrolled between January 2010 and December 2017. The primary endpoint was all-cause mortality and heart transplantation. RESULTS: In a multivariate analysis, the predictors of all-cause death were left atrial diameter [Hazard ratio (HR): 1.056, 95% confidence interval (CI): 1.020-1.093, P = 0.002]; non-left bundle branch block [HR: 1.793, 95% CI: 1.131-2.844, P = 0.013]; high sensitivity C-reactive protein [HR: 1.081, 95% CI: 1.029-1.134 P = 0.002]; and N-terminal pro-B-type natriuretic peptide [HR: 1.018, 95% CI: 1.007-1.030, P = 0.002]; and New York Heart Association class IV [HR: 1.018, 95% CI: 1.007-1.030, P = 0.002]. The Alpha-score (Atrial diameter, non-LBBB, Pro-BNP, Hs-CRP, NYHA class IV) was derived from each independent risk factor. The novel score had good calibration (Hosmer-Lemeshow test, P > 0.05) and discrimination for both primary endpoints [c-statistics: 0.749 (95% CI: 0.694-0.804), P < 0.001] or heart failure hospitalization [c-statistics: 0.692 (95% CI: 0.639-0.745), P < 0.001]. CONCLUSION: The Alpha-score may enable improved discrimination and accurate prediction of long-term outcomes among NICM patients with CRT.

Associations Between Multiple Circulating Biomarkers and the Presence of Atrial Fibrillation in Hypertrophic Cardiomyopathy with or Without Left Ventricular Outflow Tract Obstruction.

Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Data regarding the correlations of biomarkers and AF in HCM patients are rather limited. We sought to explore the associations between the presence of AF and circulating biomarkers reflecting cardiovascular function (N-terminal pro-brain natriuretic peptide, NT-pro BNP), endothelial function (big endothelin-1, big ET-1), inflammation (high-sensitivity C-reactive protein), and myocardial damage (cardiac troponin I, cTnI) in HCM patients with and without left ventricular outflow tract obstruction (LVOTO).In all, 375 consecutive HCM in-hospital patients were divided into an AF group (n = 90) and a sinus rhythm (SR) group (n = 285) according to their medical history and electrocardiogram results.In comparison with the SR group, peripheral concentrations of big ET-1, NT-pro BNP, and cTnI were significantly higher in patients with AF. Only the biomarker of big ET-1, together with palpitation and left atrial diameter (LAD), was independently associated with AF in HCM patients. Ln big ET-1 was positively related to Ln NT-pro BNP, LAD, and heart rate, but negatively related to left ventricular ejection fraction. Combined measurements of big ET-1 ≥ 0.285 pmol/L and LAD ≥ 44.5 mm indicated good predictive values in the presence of AF, with a specificity of 94% and a sensitivity of 85% in HCM patients.Big ET-1 has been identified as an independent determinant of AF, regardless of LVOTO, and is significantly related to parameters representing cardiac function and remodeling in HCM. Big ET-1 might be a valuable index to evaluate the clinical status of AF in HCM patients.

Atrial involvement in arrhythmogenic right ventricular cardiomyopathy patients referred for ventricular arrhythmias ablation.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable myocardium disorder that predominantly affects the ventricle. Little is known about atrial involvement. This study aimed to assess atrial involvement, especially the role of genotype on atrium in ARVC. METHODS: The incidence, characterization and predictors of atrial involvement were investigated. Nine known ARVC-causing genes were screened and the correlation between genotype and atrial involvement was assessed. RESULTS: Right atrium (RA) dilation, left atrium (LA) dilation, and sustained atrial tachyarrhythmias (ATa) were found in 45, 16 and 3 patients, respectively. Gene mutations were identified in 64 (64.0%) patients. Mutation carriers showed more RA dilation than noncarriers (54.7% vs. 27.8%, P = 0.009), and no difference in LA dilation and ATa. Multivariate analysis showed tricuspid regurgitation (OR: 18.867; 95% CI: 1.466-250.000; P = 0.024) increased the risk of RA dilation and decreased left ventricular ejection fraction (LVEF) (OR: 1.134; 95% CI: 1.002-1.272; P = 0.031) correlated with LA dilation, whereas genotype showed no significant effect. At a median follow-up time of 91 months, 7 patients died and 1 patient accepted heart transplantation. New-onset RA dilation, LA dilation, and sustained ATa were found in 8, 7, and 6 patients, respectively. Atrial involvement was not associated with the long-term survival. Despite mutation carriers showing more RA dilation, Kaplan-Meier analysis showed genotype was not associated with atrial involvement. CONCLUSION: Atrial involvement was common in ARVC. Tricuspid regurgitation and decreased LVEF increased the risk for atrial dilation. Genotype was not associated with atrial involvement.

Clinical outcome of left ventricular multipoint pacing versus conventional biventricular pacing in cardiac resynchronization therapy: a systematic review and meta-analysis.

Cardiac resynchronization therapy (CRT) is an effective treatment for selected patients with systolic heart failure. Unlike conventional biventricular pacing (BIP), the left ventricular multipoint pacing (MPP) can increase the number of left ventricular pacing sites via a quadripolar lead positioned in the coronary sinus. This synthetic study was conducted to integratively and quantitatively evaluate the clinical outcome of MPP in comparison with BIP. We systematically searched the databases of EMBASE, Ovid medline, and Cochrane Library through May 2018 for studies comparing the clinical outcome of MPP with BIP in the patients who accepted CRT. Hospitalization for reason of heart failure, left ventricular eject fraction (LVEF), CRT response, all-cause morbidity, and cardiovascular death rate was collected for meta-analysis. A total of 11 studies with 29,606 participants were included in this meta-analysis. Compared with BIP group, MPP decreased heart failure hospitalization (OR, 0.41; 95% CI, 0.33 to 0.50; P < 0.00001), improved LVEF (mean difference, 4.97; 95% CI, 3.11 to 6.83; P < 0.00001), increased CRT response (OR, 3.64; 95% CI, 1.68 to 7.87; P = 0.001), and decreased all-cause morbidity (OR, 0.41; 95% CI, 0.26-0.66; P = 0.0002) and cardiovascular death rate (OR, 0.21; 95% CI, 0.11-0.40; P < 0.00001). The published literature demonstrates that MPP was more effective than BIP in the heart failure patients who accepted cardiac resynchronization therapy.

Combining Percutaneous Ultrasound-Guided Hematoma Aspiration and Compression Repair to Treat Femoral Artery Pseudoaneurysm after Cardiac Catheterization.

This study aimed to prospectively evaluate the safety and efficacy of a new developed method that uses percutaneous ultrasound-guided hematoma aspiration followed by targeted localized manual compression for treatment of femoral artery pseudoaneurysm after cardiac catheterization, which obviates thrombin use, surgery, and long-time compression.From January 2007 to July 2014, 32 patients (17 women; mean age, 55.3 ± 11.5 years) out of 8,725 consecutive cases undergoing cardiac catheterization via femoral access developed one pseudoaneurysm each ranging in size from 21 × 11 mm to 72 × 39 mm. Under ultrasound guidance, blood within the pseudoaneurysm was aspirated percutaneously using an 18-gauge needle, while the pseudoaneurysm neck and a nearby site over the pseudoaneurysm were manually compressed for 15 min. All patients underwent repeat ultrasound examination 24 hours later.Of the 32 pseudoaneurysms, 31 were successfully occluded, and 1 recurred in a patient with coexisting arteriovenous fistula, yielding an overall success rate of 96.9% (31/32). No further recurrence or procedure related complications were observed. The treatment approach is unlike open surgical repair with hematoma evacuation and arterial defect suturing, in that it entails hematoma aspiration and feeding flow blockage at the pseudoaneurismal neck.In this preliminary experience, combining percutaneous ultrasound-guided hematoma aspiration and manual compression appears safe and effective in treating femoral artery pseudoaneurysms after catheterization and avoids thrombin use, long-time compression, and surgery.

Electrical Storm in ICD Recipients with Arrhythmogenic Right Ventricular Cardiomyopathy.

BACKGROUND: Implantable cardioverter defibrillator (ICD) is the most important management for prevention of sudden cardiac death (SCD) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). However, some patients may receive multiple ICD therapies in a short period, a condition referred as "electrical storm" (ES). OBJECTIVES: This study aimed to determine the prevalence, therapeutic options, and prognostic implications of ES in ARVC patients with an ICD. METHODS: We retrospectively analyzed the baseline and follow-up data of 39 ARVC patients with an ICD. ES was defined as three or more separated episodes of ventricular tachycardia or ventricular fibrillation (VT/VF) within a 24-hour period. RESULTS: During a median follow-up of 49 months (range 6-225), 12 of 39 (31%) patients suffered at least one episode of ES. The interval between the first ES and the initial ICD implantation ranged from 1 month to 109 months, and ES was the first ICD discharge in three patients. The median number of VT/VF events per ES was four (range 3-39). Five patients experienced 20 episodes of ES that were treated by antitachycardia pacing only, while the other seven patients suffered shock therapies during ES. In three patients, ES required emergency hospitalization, and the repeatedly occurred VT/VF was finally subsided by intravenous amiodarone. There was no significant difference in actual survival between patients with and without such an event. CONCLUSIONS: ES is not rare in ARVC patients with an ICD for prevention of SCD, but it does not independently confer increased mortality. Intravenous amiodarone is effective in management of ES when VT/VF repeatedly occurred.

Short-Term Availability of Viable Left Ventricular Pacing Sites with Quartet™ Quadripolar Leads.

BACKGROUND Whether quadripolar leads can provide sufficient viable left ventricular pacing sites (LVPSs) for device optimization and multipoint pacing remains unclear. This study aimed to evaluate the acute and 3-month availability of viable LVPSs provided by a quadripolar LV pacing lead. MATERIAL AND METHODS A single-center cohort study evaluated consecutive patients who underwent a CRT implant with the QuartetTM LV lead under local guidelines. The availability of viable LVPSs was assessed at the pre-discharge and 3-month follow-up visit. Bipolar lead configurations, which served as the control group, were modeled by eliminating the 2 proximal electrodes on the Quartet™ LV lead. RESULTS A total of 24 patients were enrolled and finished 3-month follow-up. The mean follow-up period was 93±3 days. At pre-discharge, the Quartet™ LV lead provided more viable LVPSs compared with the bipolar equivalents (median 3 [IQR 2-4] vs. median 2 [IQR 1-2], P<0.001). The percentage of patients with at least 1, 2, 3, and 4 viable LVPSs were 100% (24/24), 91.7% (22/24), 58.3% (14/24), and 33.3% (8/24) for Quartet™ leads and 91.7% (22/24), 70.8% (17/24), 0% (0/24), and 0% (0/24) for bipolar lead configurations, respectively. The median and IQR values of viable LVPSs provided by the Quartet™ LV lead remained the same (3 [IQR 2-4]) between pre-discharge and 3-month follow-up (P=0.45). CONCLUSIONS Compared with the bipolar equivalent, QuartetTM LV lead provides more viable LVPSs and opportunities for CRT optimization and multipoint LV pacing. The number of LVPSs provided by Quartet™ leads remained unchanged between pre-discharge and 3-month follow-up.

Comparison of Radiofrequency Catheter Ablation Between Asymptomatic and Symptomatic Persistent Atrial Fibrillation: A Propensity Score Matched Analysis.

BACKGROUND: Whether patients with asymptomatic atrial fibrillation (AF) could benefit from radiofrequency catheter ablation (RFCA) remains unclear. This study aimed to compare the outcomes of RFCA between asymptomatic and symptomatic AF. METHODS: Sixty-six patients with asymptomatic persistent AF who underwent the primary ablation for AF were enrolled; 132 patients with symptomatic persistent AF were matched using propensity score matching. All patients underwent circumferential pulmonary vein isolation in combination with linear ablation using AF termination as the primary procedural endpoint. RESULTS: Sinus rhythm (SR) was restored by ablation in 18 (27.3%) patients in the asymptomatic group and 93 (70.5%) in the symptomatic group (P < 0.001). Combined with intravenous infusion of ibutilide (1 mg), the numbers were 45 (68.2%) and 116 (87.8%), respectively (P = 0.001). At 1-year follow-up, SR was present in 23 (34.8%) patients in the asymptomatic group and 78 (59.1%) in the symptomatic group without any antiarrhythmic medication after a single procedure (P = 0.001). Of the 43 patients experiencing recurrence in the asymptomatic group, 16 (37.2%) had recurrent atrial tachycardia (AT)-related symptoms. Multivariate analysis showed that asymptomatic AF was independently associated with AF failed to be terminated by ablation (OR: 7.1; 95% CI: 3.4 to 14.9; P < 0.001) and recurrence (OR: 2.2; 95% CI: 1.1 to 4.4; P = 0.018). Patients with asymptomatic AF showed less improvement in quality of life postablation than those with symptoms. CONCLUSION: Current catheter ablation techniques showed worse outcomes in asymptomatic AF patients than in those with symptoms. Recurrent AT could cause significant symptoms in previously asymptomatic patients.

Catheter ablation for ventricular tachycardia following surgical treatment of pulmonary stenosis with intact ventricular septum.

AIMS: This study was aimed to report the characteristics and treatment of ventricular tachycardia (VT) following surgical treatment of pulmonary stenosis with intact ventricular septum. METHODS AND RESULTS: Five patients underwent radiofrequency catheter ablation for sustained monomorphic left bundle branch block (LBBB) type VT who previously underwent surgical treatment of pulmonary stenosis. Except stimulation, voltage and activation mapping was performed using three-dimensional (3D) electro-anatomic mapping and ablation was applied accordingly. Four VTs were induced during EP study. Two VTs were focal and the earliest activity was targeted in the right ventricular apex (RVA). The other two VTs were reentrant and the critical isthmus located in the mid-lateral wall and anterior wall of right ventricle, respectively. Ablation abolished all inducible VTs in four patients. In the patient whose VT was non-inducible, radiofrequency (RF) energy was delivered to the RVA where pacing mapping matched the clinical VT. One focal VT recurred 60 months after the initial RF ablation. Repeat mapping and ablation was performed and no VT recurred over a 24-month period. CONCLUSIONS: The mechanism of VT following surgical treatment of pulmonary stenosis can be either focal or reentrant. Ablation of this subgroup of VT is feasible.

Cardiac resynchronization therapy reduces T-wave alternans in patients with heart failure.

AIMS: T-wave alternans (TWA) represents myocardial instability. The present study was to determine the impact of cardiac resynchronization therapy (CRT) on TWA and left ventricular ejection fraction (LVEF) in heart failure patients. METHODS AND RESULTS: T-wave alternans was analysed using a spectral method in 27 CRT-ICD patients. Ambulatory device electrograms were collected and LVEF and New York Heart Association (NYHA) classification were assessed at baseline prior to CRT and 3 months following CRT. Patients were followed for 6 months to monitor cardiac events. Spectral TWA of device electrograms was measured during AAI and CRT pacing tests. Each pacing mode had the up-titration pacing rate from 90 to 105 b.p.m. with 90 s for each pacing rate. At baseline, 20 (76.9%) patients had TWA during AAI pacing tests and 13 (50%) during CRT pacing tests (P = 0.044 between two pacing modes). Following 3-month CRT, TWA was identified in 11 patients (45.8%) during AAI pacing tests (a 31.1% reduction from the baseline value, P = 0.023) and 7 patients (28%) during CRT pacing tests (a 22% reduction, P = 0.108). Six of seven patients who had cardiac events had TWA (three patients had arrhythmic events, two died of heart failure, one received heart transplant). Overall, LVEF improved from 27.3 ± 5.8 to 35.9 ± 10.5% (P < 0.001) and NYHA classification improved from 2.8 ± 0.6 to 1.6 ± 0.6 after 3-month CRT (P < 0.001). CONCLUSION: In heart failure patients who receive a CRT-ICD, CRT reduces TWA that is associated to cardiac events, suggesting that CRT promotes clinically significant reverse electrical and mechanical remodelling.

Regression of fragmented QRS complex: a marker of electrical reverse remodeling in cardiac resynchronization therapy.

BACKGROUND: Fragmented QRS (fQRS) marks inhomogeneous activation and asynchronous cardiac contraction. It has been proved that cardiac resynchronization therapy (CRT) could reverse geometrical remodeling as well as correct electrical dyssynchrony. We aimed to investigate whether fQRS changed corresponding to the therapeutic response to CRT. METHODS: Patients who underwent de novo CRT implantation previously and had ≥1 follow-up between August 2012 and September 2013 in our hospital were investigated. Intrinsic electrocardiogram was recorded and fQRS in any lead was calculated. Response to CRT was defined as absolute improvement in left ventricular ejection fraction by ≥10% or by improvement >1 New York Heart Association class and without heart failure hospitalization. RESULTS: A total of 75 patients (48 male, mean ages, 61 ± 9 years) were included in this study. At a median follow-up of 13 months, 57 patients had response to CRT. Responders had narrowed QRS (from 167 ± 23 ms to 158 ± 19 ms, P = 0.003) and reduced fQRS post-CRT. Nonresponders had QRS prolonging (from 151 ± 26 ms to 168 ± 16 ms, P = 0.033) and increase in fQRS. Eleven of 12 patients with reduced fQRS were responders and 8 of 12 with increased fQRS were nonresponders. Both changes in QRS and fQRS correlated strongly with CRT response (r = 0.389, P = 0.001 and r = 0.403, P = 0.000, respectively). Reduction of fQRS in ≥1 leads had high specificity (95%) in association to responders, though in low sensitivity (19%). CONCLUSIONS: The changes in fQRS associated with therapeutic response to CRT. Regression of fQRS could be a maker of electrical reverse remodeling following CRT.

[Association of serum free triiodothyronine with long-term outcome in heart failure patients receiving cardiac resynchronization therapy].

OBJECTIVE: To explore the prognostic role of free triiodothyronine (FT3) on all-cause mortality and heart failure (HF) hospitalization in patients receiving cardiac resynchronization therapy (CRT). METHODS: In this single-center retrospective cohort study, a total of 202 chronic heart failure (CHF) patients who had CRT implantation from January 2010 to December 2014 were enrolled. Clinical outcomes were defined as all-cause mortality (including heart transplantation) and new heart failure (HF) hospitalization. Patients were divided into three groups according to FT3 tertiles: FT3≤4.08 pmol/L group (n=67), FT3 4.09-4.71 pmol/L group (n=68) and FT3>4.71 pmol/L group (n=67). Kaplan-Meier analyses were performed for each outcome. Cox proportional-hazards regression analyses were used to evaluate the independent prognosis of FT3 in CRT treated patients. RESULTS: Patients in FT3≤4.08 pmol/L group tended to be older, with more women patients, and had lower estimated glomerular filtration rate (eGFR), hemoglobin and serum sodium concentration. They were also less frequently subjected to smoking, alcohol consumption and were less likely prescribed with renin-angiotensin-aldosterone system inhibitors. Also, this group had highest proportion of NYHA class Ⅳ patients. Kaplan-Meier analyses demonstrated that FT3 4.09-4.71 pmol/L group was associated with a significantly better survival (P=0.022) and less new hospitalizations for HF event (P=0.020). Cox regression analyses indicated that FT3 4.09-4.71 pmol/L was an independent protective factor for both all-cause mortality (HR=0.220, 95%CI: 0.069-0.700, P=0.011) and HF hospitalization (HR=0.490, 95%CI: 0.241-0.996, P=0.049). Left ventricular end diastolic diameter (LVEDd) enlargement was an independent risk factor of all-cause mortality(HR=1.043, 95%CI: 1.004-1.083, P=0.031). CONCLUSION: Patients in FT3 4.09-4.71 pmol/L group had the lowest risk of all-cause mortality and HF hospitalization after CRT implantation.

Intracardiac thrombosis in patients with arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Intracardiac thrombus has been reported in anecdotal cases of arrhythmogenic right ventricular cardiomyopathy (ARVC). This prospective study aimed to determine the prevalence, risk factors, and prognosis of intracardiac thrombosis in patients with ARVC. METHODS: From February 2004 to August 2013, transthoracic echocardiograms and magnetic resonance imagings were performed in 193 patients with ARVC. The prevalence, risk factors, and prognosis of intracardiac thrombosis were investigated. RESULTS: Ten intracardiac thrombi were identified in 8 patients (4.1%), the majority (7/10) of which were found in the right ventricular apex. Multivariate analysis showed that female gender and left ventricular dysfunction were independently associated with increased risk for thrombosis in ARVC. All thrombi were eliminated in 3 weeks after anticoagulation therapy without any complication. During a median follow-up time of 38 months (range 2 to 128), no thromboembolism event or sudden death was observed in patients under anticoagulation therapy; however, in patients without anticoagulation therapy, definite pulmonary thromboembolism occurred in 1 and sudden death due to suspected pulmonary thromboembolism was observed in another. CONCLUSION: Intracardiac thrombosis may occur in certain patients with ARVC. Female gender and left ventricular dysfunction appeared to be associated with increased risk for thrombosis. Early screening and effective anticoagulation therapy may improve the prognosis.