NaNbO3/NaTaO3 Superlattices: Cation-Ordering Improved Band-Edge Alignment for Water Splitting and CO2 Photocatalysis.

Perovskite oxide heterostructures have been extensively investigated for their excellent photocatalytic properties. Here, through hybrid density functional theory calculations, we systematically investigate the formation of NaNbO3-NaTaO3 (NBO-NTO) heterostructures. The sequential cations replacement in the superlattices reveals the Nb-Ta ratio range that allows the effective formation of heterostructures, which occurs through a spontaneous polarization mechanism induced by the electrostatic potential discontinuity in the interface. The resulting cation ordering is responsible for the sawtooth-like potential distribution that spatially separates valence and conduction charges and reduces the heterostructure bandgap. The symmetric NBO5/NTO5 junction has the smallest bandgap (2.50 eV) whose transitions are associated with Nb 5dxy orbitals on the interfacial plane. Such a relaxation mechanism provides the heterostructure with anisotropic optical properties and interface absorption peaks closer to the visible light spectrum. The phenomena strongly suggest the use of these heterostructures in photocatalytic reactions, supported by their coherent band-edge alignment with both water splitting and CO2 reforming potentials.

Prognostic effect and modulation of cardiac sympathetic function in heart failure patients treated with cardiac resynchronization therapy.

BACKGROUND: Cardiac autonomic dysfunction as assessed by 123I-metaiodobenzylguanidine (123I-mIBG) scintigraphy is associated with poor prognosis in heart failure (HF) patients. Although cardiac resynchronization therapy (CRT) has emerged as an effective therapy in improving outcomes on HF patients, its effect on cardiac sympathetic nervous function is still not fully understood. We aimed to study the value of pre-implantation 123I-mIBG late heart-to-mediastinum ratio (HMR) as a predictor of response and outcomes after CRT and to correlate modification in this parameter with CRT response and functional improvement. METHODS AND RESULTS: BETTER-HF (Benefit of exercise training therapy and cardiac resynchronization in HF patients) is a prospective randomized clinical trial including HF patients submitted CRT (mean LVEF 24 ± 8%, 74% NYHA class ≥ III) who underwent a clinical, echocardiographic, and scintigraphic assessment before and 6 months after CRT. One-hundred and twenty-one patients were included. Echocardiographic response was observed in 54% and composite outcome of cardiac mortality, cardiac transplant or heart failure hospitalization in 24% of patients. Baseline late HMR was an independent predictor of CRT response (regression coefficient 2.906, 95% CI 0.293-3.903, P .029) and outcomes (HR 0.066 95% CI 0.005-0.880, P .040). At follow-up, 123I-mIBG imaging showed positive changes in cardiac sympathetic nerve activity only in responders to CRT (1.36 ± 0.14 prior vs. 1.42 ± 0.16 after CRT, P .039). There was a significant correlation between improvement in late HMR and improvement in peak oxygen consumption (r 0.547, P < .001). CONCLUSION: In our study, baseline cardiac denervation predicted response and clinical outcomes after CRT implantation. Cardiac sympathetic function was improved only in patients who responded to CRT and these positive changes were correlated with improvement in functional capacity.

Structural and electronic properties of NaTaO3 cubic nanowires.

Sodium tantalate nanostructures have been classified among the best materials to conduct photocatalytic reactions. Therefore, understanding the relationship between nanoscale surface phenomena and photocatalytic properties is of fundamental importance. We performed Density Functional Theory calculations to investigate how chemically different facets may affect intrinsic properties of NaTaO3 cubic nanowires. Besides half-metallicity, the NaO-terminated wire relaxes structurally, presenting unoccupied down O 2p levels located above its valence band due to severely reduced coordination of its edges, which may allow it to be applied in spintronics systems. NaTaO-terminated wires have surface TaO4 units that, upon structural reconstruction, become more planar and introduce occupied Ta 5d levels below their conduction band. The emergence of such levels is also related to the overlap of Ta dz2 orbitals from adjacent NaTaO facets. Amongst other properties discussed herein, localized levels may be relevant for photocatalysis not only in terms of intrinsic bandgap engineering but also concerning the alignment with water redox potentials.

Modulation of band alignment with water redox potentials by biaxial strain on orthorhombic NaTaO3 thin films.

Photocatalysis-assisted water splitting using semiconductor materials greatly depends on the bandgap size and the alignment of band edges relative to the reaction potentials. We used ab initio computational methods to show that the biaxial strain on [100]-oriented orthorhombic NaTaO3 thin films grants the modulation of surface states, favoring either the hydrogen evolution reaction (HER) or the oxygen evolution reaction (OER), which basically rules the perovskite photocatalytic performance. Under compression, the outermost TaO6 and TaO4 polyhedra become more distorted, and electrostatic repulsion increases the energy of Ta 5d surface states. As they overcome the O2/H2O potential, they cease to contribute to the OER. At the same time, the H+/H2 remains below the conduction band, leveraging the HER over the OER. The tensile strain lowers the outermost polyhedra distortions, stabilizing both Ta 5d surface and conduction band states, and increasing the charge centered around surface Ta atoms. Consequently, the bands are better aligned with O2/H2O and H+/H2 potentials, which benefits the overall water splitting photocatalysis. Our results evidence that combining facet and strain engineering is an effective way of altering the photocatalytic activity of orthorhombic [100] NaTaO3 thin films.

Relationship of left ventricular global longitudinal strain with cardiac autonomic denervation as assessed by 123I-mIBG scintigraphy in patients with heart failure with reduced ejection fraction submitted to cardiac resynchronization therapy : Assessment of cardiac autonomic denervation by GLS in patients with heart failure with reduced ejection fraction submitted to CRT.

BACKGROUND: Heart failure (HF) is associated with cardiac autonomic denervation (AD), which can be non-invasively assessed by 123I-metaiodobenzylguanidine (123I-mIBG) scintigraphy and has prognostic implications. We aimed to study the relationship between myocardial contractility assessed by global longitudinal strain (GLS) and AD assessed by 123I-mIBG scintigraphy in advanced HF. METHODS/RESULTS: BETTER-HF is a prospective randomized clinical trial including HF patients (pts) submitted to cardiac resynchronization therapy (CRT) who are submitted to a clinical, echocardiographic, and scintigraphic assessment before and 6 months after CRT. 81 pts were included. An echocardiographic response (absolute increase in left ventricular ejection fraction ≥ 10%) was observed in 73.7% of pts. A higher baseline late heart-to-mediastinum ratio (HMR) was associated with a better echocardiographic response. There was a significant association between late HMR and GLS at baseline and 6 months. At baseline, GLS had an AUC of 0.715 for discrimination for a late HMR < 1.6. A GLS cut-off of - 9% maximized the likelihood of correctly classifying a pt as having severe AD (HMR < 1.6). CONCLUSION: Myocardial contractility as assessed by GLS is moderately correlated with AD as assessed by 123I-mIBG scintigraphy and has a good discrimination for the identification of severe cardiac denervation. GLS may allow for a more readily accessible estimation of the degree of AD in advanced HF pts.

Cardiotoxicity in breast cancer treatment: What about left ventricular diastolic function and left atrial function?

AIMS: Cardiotoxicity is a possible complication of cancer treatment, particularly with anthracyclines and anti-HER2 drugs. Systolic dysfunction has already been described. Diastolic dysfunction and left atrial function are less studied. We sought to analyze the impact of cardiotoxic treatments on left ventricular diastolic function and left atrial (LA) function. METHODS AND RESULTS: Retrospective study of 100 patients (all women, with a mean age of 54 ± 12 years) with three exams in the span of 1 year during treatment for breast cancer. Patients with previous cancer treatment, coronary artery disease, significant valvular disease, and atrial arrhythmias were excluded. Diastolic dysfunction was classified according to international guidelines and left atrial strain was analyzed by two-dimensional speckle tracking. In our sample, 74% received anthracyclines, 83% anti-HER2, and 76% radiation treatment. In the follow-up, 20% developed new or worsening diastolic dysfunction. Age was the only independent predictor (OR 1.93, 95% CI 1.04-3.58, P = .037). In left atrial function, only the contractile function was significantly reduced in 20.8% of the patients and age was also the only independent predictor, but with a protective effect (OR 0.51, 95% CI 0.28-0.91, P = .023). CONCLUSIONS: During breast cancer treatment, 20% of the patients develop new or worsening diastolic dysfunction, being age the main determinant, suggesting higher impact of chemotherapy in older patients. Contractile left atrial function is also compromised but, in this case, age seems to be protective. Our results support a stricter surveillance in older patients together to eventually adjust chemotherapy regimens.

In vivo validation of a novel algorithm for automatic premature ventricular contractions recognition.

INTRODUCTION: Template-matching algorithms are routinely used in the catheter ablation of patients with premature ventricular contractions (PVCs). However, systematic analysis of the accuracy and spatial resolution of such systems is lacking. Therefore, the aim of this evaluation was to perform a systematic in vivo validation of performance of a novel automated template-matching algorithm. METHODS AND RESULTS: In a porcine model, paced beats simulating PVCs from different origins were investigated. The ability to discriminate between sinus rhythm and PVCs was tested by simulating PVCs using sequential pacing from different cardiac chambers. The accuracy of the algorithm in correctly classifying PVCs was reviewed by an independent investigator. In addition, the spatial resolution of pace matching was evaluated by assessing the QRS morphology discrimination at a distance of 0, 2, 4, and 6 mm of a simulated PVCs focus. The specificity of the algorithm for recognizing simulated PVCs was 99.6% and the sensitivity was 85.3%. There was a significant difference in the discrimination metric discrimination metric (with 0% being a perfect match and 100% being no correlation) between PVC origin (median 0%, interquartile range (IQR) 0-2%) versus at 2 mm (5%, IQR 2-7%), 4 mm (16%, IQR 11-21%), and 6 mm (24%, IQR 19-28%, P < 0.001 for all). The c-statistic for discrimination between PVC origin and a distance ≥ 2 mm was 0.93. CONCLUSIONS: Automated template matching had high specificity and sensitivity, with good spatial discrimination and a pace-mapping resolution in range of 2 mm. Clinical application of this algorithm may assist in the interventional treatment of patients with PVCs.

Modified continuity equation using left ventricular outflow tract three-dimensional imaging for aortic valve area estimation.

PURPOSE: Aortic valve area (AVA) is usually estimated by the continuity equation (CE) in which the left ventricular outflow tract (LVOT) area is calculated assuming a circular shape. This study aimed to compare measurements of LVOT area using standard 2D transthoracic echocardiography (2DTTE), 3D transesophageal echocardiography (3DTEE), and multidetector computed tomography (MDCT) and assess their relative impact on AVA estimated by the CE. METHODS AND RESULTS: We prospectively enrolled 60 patients with severe aortic stenosis (AS) referred for transcatheter aortic valve replacement (TAVR) who systematically underwent 2DTTE, 3DTEE, and MDCT. Mean LVOT areas obtained by 2DTTE (3.28±0.66 cm2 ) and 3DTEE (3.95±0.90 cm2 ) were significantly underestimated when compared to the mean MDCT LVOT area (4.31±0.99 cm2 ). LVOT was rather elliptical than round, with a mean eccentricity index of 1.47 (ratio of maximum to minimum LVOT diameters) assessed by MDCT. Mean TTE AVA estimated by the CE was 0.62±0.20 cm2 . Substitution of 2DTTE LVOT area by 3DTEE LVOT area in the CE resulted in AVA of 0.74±0.24 cm2 , while using MDCT LVOT area held an AVA of 0.80±0.24 cm2 . MDCT-derived AVA was similar to MDCT planimetric AVA and allowed 24% of patients to be reclassified from severe to moderate AS. CONCLUSIONS: 2DTTE and 3DTEE underestimate LVOT area when compared to MDCT with significant impact on AVA estimation. Assessment through MDCT fusion AVA may be of incremental value in patients with discrepant severity criteria for AS.

Conventional and Novel Predictors of Permanent Pacemaker after TAVI in Atrial Fibrillation Patients.

BACKGROUND AND AIM OF THE STUDY: Atrial fibrillation (AF) is common in patients submitted for transcatheter aortic valve implantation (TAVI), and these patients are at higher risk of developing conduction system disturbances requiring pacemaker (PM) implantation. Conventional predictors for PM use in this population have limited applicability. It was hypothesized that a post-procedural heart rate reduction could gauge the degree of atrioventricular (AV) node injury, and that this would be a clinically useful predictor of a need for PM. METHODS: All consecutive patients submitted for TAVI between December 2009 and August 2015 were included prospectively in a local registry. Clinical and electrocardiographic data and procedural details were recorded, and patients in sinus rhythm or with pre-existing PM were excluded. Heart rate (HR) at the start and end of the procedure were used to assess post-procedural HR reduction by calculating the HR ratio (HRratio = HRend/HRstart). The relationship between previously described predictors of PM, HRratio and implantation of a permanent PM during the 30 days after TAVI were analyzed using the Wilcoxon ranksum test and receiver operating characteristic (ROC) curve. RESULTS: A total of 102 patients was submitted for TAVI, 24 of whom had AF and no previous PM. Of the latter 24 patients, 10 (41.6%) received a PM during the 30 days after TAVI. Conventional predictors of permanent PM such as male gender, left anterior hemiblock and right bundle branch block were not significantly associated with PM implantation. The HRratio was significantly lower in patients submitted for PM implantation (median 0.76, IQR 0.68-0.86 versus 1.18, IQR 1.10-1.26; p <0.001; Wilcoxon ranksum test). ROC curve analysis of the HRratio showed a good discrimination for the need of PPM with a c-statistic of 0.93. An optimal cut-off value of 0.9 predicted the need for PM implantation with a sensitivity of 90% and specificity of 92.8% CONCLUSIONS: Conventional predictors of PM after TAVI were not associated with PM implantation in patients with AF. The fall in post-procedural HR was significantly associated with PM implantation, with an HRratio cut-off value of 0.9 accurately predicting a need for PM within 30 days.

Contribution of Dobutamine Stress Echocardiography to the Diagnosis and Prognosis of Low-Flow/Low-Gradient Aortic Stenosis.

BACKGROUND: Aortic valve replacement (AVR) is the treatment of choice in patients with severe symptomatic aortic stenosis (AS). Patients with a low left ventricular ejection fraction (LVEF) represent a challenge for evaluation and therapeutic decision. Dobutamine stress echocardiography (DSE) allows the distinction to be made between fixed low-flow/low-gradient (LF/LG) AS and pseudosevere AS. METHODS: Between 2001 and 2014 a retrospective analysis was conducted of patients who underwent DSE to investigate severe AS. DSE was performed in 3- to 5-min steps up to a maximum dose of 20 µg/kg/min. Parameters evaluated at baseline and at each step of DSE included: left ventricular enddiastolic volume (LVEDV) and left ventricular endsystolic volume (LVESV), maximum gradient (MaxG), mean gradient (MG) and aortic valve area (AVA). AS was considered to be severe if the AVA at peak dose was ≤1 cm2. Patients were allocated to two groups according to their therapy: group 1 received only medical treatment, while group 2 underwent AVR. The average follow up was 51.5 ± 4.4 months. RESULTS: A total of 41 patients (28 males, 13 females; mean age 71.7 ± 8.3 years) was analyzed. Severe AS was diagnosed in 34 patients (83%). Baseline echocardiographic characteristics were: AVA 0.7 ± 0.2 cm2, MaxG 42.0 ± 9.1 mmHg, MG 25.6 ± 6.4 mmHg, LVEF 33.1 ± 8.4%, LVEDV 149.6 ± 44.5 ml, and LVESV 104.0 ± 42.6 ml. At peak DSE, AVA was 0.8 ± 0.2 cm2, MaxG 62.7 ± 18.2 mmHg, MG 38.1 ± 11.6 mmHg, LVEF 42.2 ± 9.9%, LVEDV 142.6 ± 43.85 ml, and LVESV 89.7 ± 37.4 ml. Nineteen patients were allocated to group 1, and 22 to group 2. In group 2, two patients underwent transcatheter aortic valve implantation (TAVI) and 20 had surgery. Mortality in group 1 was significantly higher than in group 2 (78.9% versus 27.3%). A Cox proportional hazard model analysis showed that no-intervention was the only predictor of mortality (unadjusted to age; hazard ratio (HR) 5.13, 95% confidence interval (CI) 1.96-13.44, p = 0.001; adjusted to age - HR 4.01, 95% CI 1.46-11.01, p = 0.007). CONCLUSIONS: LF/LG AS has a poor prognosis without intervention. DSE allows the lesion severity to be established. In the present study intervention was a predictor of survival during follow up.

Case report of a double-wave re-entry atrial flutter in a patient with atrial cardiomyopathy.

Background: Double-wave macrore-entry is a rare mechanism of atrial tachycardia with limited documentation in the literature. We present a three-dimensional documentation of a double-wave 'typical' atrial flutter in a patient with extensive atrial cardiomyopathy. Case summary: A 78-year-old female with a history of atrial cardiomyopathy and dual-chamber pacemaker for sinus node disease presented with palpitations and incessant atrial flutter. Electrophysiological study revealed a regular tachycardia with a cycle length (TCL) of 230 ms, with proximal to distal coronary sinus (CS) activation. Three-dimensional mapping identified two independent wavefronts circulating the cavotricuspid isthmus (CTI), each with a TCL of 460 ms. Cavotricuspid isthmus ablation resulted in conversion into a distinct tachycardia with left atrial roof origin. Linear ablation in this location slowed the TCL to 435 ms with concentric CS activation and another CTI dependent atrial flutter was mapped, this time with only one wavefront of activation. Further ablation with a second, more lateral, line in the CTI led to tachycardia interruption. Given the extensive atrial scarring and high arrhythmic recurrence risk, atrioventricular node ablation was performed. Discussion: Double-wave re-entrant tachycardias were primarily observed in experimental models, precipitating acceleration of ventricular and supraventricular tachycardias via extrastimulation. In our case, there is documentation of a spontaneous double-wave of activation around the CTI, representing the first documented double-wave 'typical' atrial flutter. Unlike other cases in the literature, the two wavefronts were equidistant, which resulted in a regular tachycardia with TCL that was half of the single-wave cycle length. Three-dimensional propagation mapping was essential to visualize the two distinct wavefronts.

Evaluation of left atrial strain imaging and integrated backscatter as predictors of recurrence in patients with paroxysmal, persistent, and long-standing persistent atrial fibrillation undergoing catheter ablation.

BACKGROUND: Impaired left atrial (LA) strain predicts atrial fibrillation (AF) recurrence after catheter ablation (CA), but currently there is no cut-off to guide patient selection for CA. Integrated backscatter (IBS) is a promising tool for noninvasive quantification of myocardial fibrosis. The aim of this study was to compare LA strain and IBS between paroxysmal, persistent, and long-standing persistent AF and evaluate their association with AF recurrence after CA. METHODS: Analysis of consecutive patients with symptomatic paroxysmal and persistent AF who underwent CA. LA phasic strain, strain rate and IBS were assessed by two-dimensional speckle-tracking at baseline. RESULTS: We analyzed 78 patients, 31% with persistent AF (46% long-standing AF), 65% male, mean age 59 ± 14 years, who underwent CA and were followed-up for 12 months. AF recurrence occurred in 22 (28%) patients. LA phasic strain parameters were significantly impaired in patients with AF recurrence and were independent predictors of AF recurrence in a multivariable analysis. LA reservoir strain (LASr) < 18% predicted AF recurrence with 86% sensitivity and 71% specificity, with a higher predictive power compared to LA volume index (LAVI). LASr < 22% in paroxysmal AF and LASr < 12% in persistent AF correlated with AF recurrence. Increased IBS was a predictor of AF recurrence in patients with paroxysmal AF. CONCLUSION: LA phasic strain parameters were predictors of AF recurrence after CA, independently of LAVI and AF subtype. LASr < 18% showed a higher predictive power compared to LAVI. Further studies are needed to investigate the role of IBS as a predictor of AF recurrence.

Very-early detection of atrial fibrillation after ablation evaluated by a wearable ECG-patch predicts late blanking period recurrence: Preliminary data from a prospective registry.

Introduction: Atrial fibrillation (AF) ablation represents a safe and effective procedure to restore sinus rhythm. The idea that post-procedural AF episodes - during the blanking period - are not considered treatment failure has been increasingly challenged. The E-Patch, a single-use adhesive electrode, facilitates extended continuous ECG monitoring for 120 h. This pilot study aims to assess the effectiveness of this ambulatory monitoring device and investigate whether very-early AF recurrence correlates with delayed blanking period ablation outcomes. Methods: We conducted a single-center, prospective, longitudinal study, including consecutive post-ablation patients monitored with the E-patch. The ability of the device to continuously record was analyzed, as well as the occurrence of AF episodes during external 7-day loop-recorder in the 2nd-month post-ablation. Results: We included 40 patients, median age 62 years (IQR 56-70). E-Patch monitoring was obtained for a median of 118 h (IQR 112-120), with no discomfort nor interpretation artefacts. Very-early AF recurrence was detected in 11 (27.5 %) patients, with a median AF burden of 7 % (IQR 6 %-33 %). Late-blanking period AF was detected in 13 (33 %) of the external 7-day loop recordings. Of the 11 patients that had very-early AF recurrence, 10 (91 %) had late-blanking AF. Very-early AF detection showed 77 % (95 % CI 64 %-90 %) sensitivity and 96 % (95 % CI 90-100 %) specificity in predicting late-blanking AF, with a non-parametric ROC curve AUC of 0.903 (95 % 0.797--1.0). Conclusion: The E-Patch was able to detect very-early AF during an extended period. Very-early AF detection emerges as a predictor of AF recurrence during the late blanking period post-ablation.

Epicardial adipose tissue volume assessed by cardiac CT as a predictor of atrial fibrillation recurrence following catheter ablation.

INTRODUCTION: In patients with atrial fibrillation (AF), up to one third have recurrence after a first catheter ablation (CA). Epicardial adipose tissue (EAT) has been considered to be closely related to AF, with a potential role in its recurrence. We aimed to evaluate the association between the volume of EAT measured by cardiac computed tomography (CT) and AF recurrence after CA. METHODS: Consecutive AF patients underwent a standardized cardiac CT protocol for quantification of EAT, thoracic adipose volume (TAV) and left atrium (LA) volume before CA. An appropriate cut-off of EAT was determined and risk recurrence was estimated. RESULTS: 305 patients (63.6 % male, mean age 57.5 years, 28.2 % persistent AF) were followed for 24 months; 23 % had AF recurrence at 2-year mark, which was associated with higher EAT (p = 0.037) and LAV (p < 0.001). Persistent AF was associated with higher EAT volumes (p = 0.010), TAV (p = 0.003) and LA volumes (p < 0.001). EAT was predictive of AF recurrence (p = 0.044). After determining a cut-off of 92 cm3, survival analysis revealed that EAT volumes > 92 cm3 showed higher recurrence rates at earlier time points after the index ablation procedure (p = 0.006), with a HR of 1.95 (p = 0.008) of AF recurrence at 2-year. After multivariate adjustment, EAT > 92 cm3 remained predictive of AF recurrence (p = 0.028). CONCLUSION: The volume of EAT measured by cardiac CT can predict recurrence of AF after ablation, with a volume above 92 cm3 yielding almost twice the risk of arrhythmia recurrence in the first two years following CA. Higher EAT and TAV are also associated with persistent AF.

Electrical storm in hypertrophic cardiomyopathy: Cardiac magnetic resonance and sudden cardiac death risk stratification: a case report.

Background: Risk stratification for sudden cardiac death (SCD) is a key factor in the management of patients with hypertrophic cardiomyopathy (HCM). Cardiac magnetic resonance (CMR) has a unique role in the evaluation of HCM and offers superior diagnostic and prognostic information to assess the indication for a prophylactic implantable cardioverter-defibrillator (ICD). Case summary: A 39-year-old patient with non-obstructive HCM with a low ESC HCM Risk-SCD score underwent a CMR revealing a left ventricular apical aneurysm and extensive late gadolinium enhancement; a prophylactic ICD was thus implanted. A month later, the patient was admitted in refractory electrical storm with over 50 appropriate ICD shocks due to sustained ventricular tachycardia. Despite anti-arrhythmic therapy and mechanical ventilation, the evolution was unfavourable with haemodynamic instability; veno-arterial extracorporeal membrane oxygenation was implanted. The patient was submitted to CMR-guided epicardial VT catheter ablation with complications of LV thrombus and severe pericardial effusion. Discussion: This case details the complex risk stratification for SCD in patients with HCM, highlighting the important role of CMR in the integrated approach to risk stratification.

Apical or Septal Right Ventricular Location in Patients Receiving Defibrillation Leads: A Systematic Review and Meta-Analysis.

This study reviews the published data comparing the efficacy and safety of apical and septal right ventricle defibrillator lead positioning at 1-year follow-up. Systemic research on Medline (PubMed), ClinicalTrials.gov, and Embase was performed using the keywords "septal defibrillation," "apical defibrillation," "site defibrillation," and "defibrillation lead placement," including implantable cardioverter-defibrillator and cardiac resynchronization therapy devices. Comparisons between apical and septal position were performed regarding R-wave amplitude, pacing threshold at a pulse width of 0.5 ms, pacing and shock lead impedance, suboptimal lead performance, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter, readmissions due to heart failure and mortality rates. A total of 5 studies comprising 1438 patients were included in the analysis. Mean age was 64.5 years, 76.9% were male, with a median LVEF of 27.8%, ischemic etiology in 51.1%, and a mean follow-up period of 26.5 months. The apical lead placement was performed in 743 patients and septal lead placement in 690 patients. Comparing the 2 placement sites, no significant differences were found regarding R-wave amplitude, lead impedance, suboptimal lead performance, LVEF, left ventricular end-diastolic diameter, and mortality rate at 1-year follow-up. Pacing threshold values favored septal defibrillator lead placement (P = 0.003), as well as shock impedance (P = 0.009) and readmissions due to heart failure (P = 0.02). Among patients receiving a defibrillator lead, only pacing threshold, shock lead impedance, and readmission due to heart failure showed results favoring septal lead placement. Therefore, generally, the right ventricle lead placement does not appear to be of major importance.

Clinical outcome of a single procedure cryoballoon ablation for the treatment of atrial fibrillation: A real-world multicenter experience in Portugal.

BACKGROUND: Cryoballoon ablation (CBA) for pulmonary vein isolation (PVI) has been growing as an alternative technique, not only in patients with paroxysmal atrial fibrillation (PAF) but also in persistent atrial fibrillation (AF). Cryoballoon ablation has demonstrated encouraging acute and mid-term results. However, data on long-term follow-up of CB-based PVI are scarce. OBJECTIVE: We sought to examine efficacy, safety, and long-term outcomes of CBA in PAF and persistent AF in four Portuguese centers. METHODS: All patients that were treated with the cryoballoon catheter according to routine practices with a second-generation 28-mm CB in four centers were included. This was a retrospective, non-randomized analysis. Patients were followed-up for >12 months and freedom from atrial arrhythmias (AA) was evaluated at the end of follow-up. RESULTS: Four hundred and six patients (57.7±12.4 years, 66% men) participated. AF was paroxysmal in 326 patients (80.2%) and persistent in 80 (19.7%). The mean procedure time duration was 107.7±50.9 min, and the fluoroscopy time was 19.5±9.7 min. Procedural/periprocedural complications occurred in 30 cases (7.3%), being transient phrenic nerve palsy the most frequent incident (2 out of 3 complications). Anatomic variations of the PV were present in 16.1% of cases. At a mean follow-up of 22.0±15.0 months, 310 patients (76.3%) remained in stable sinus rhythm, with at least one AF episode recurrence documented in 98 cases (24.1%). The recurrence rate was 20.5% in the PAF group and 37.8% in the persistent AF group. CONCLUSION: In this multicenter experience, a single CBA procedure resulted in 75.9% freedom from AF at a 22-month follow-up. This technique was demonstrated to be a safe and effective option in experienced centers for the treatment of PAF and PersAF.

A simplified single transseptal puncture approach using high-density 3D voltage mapping for atrial fibrillation ablation: acute complications and long-term results.

Background: An ablation catheter and a circular mapping catheter requiring a double transeptal puncture (TSP) for left atrial access have been conventionally used for atrial fibrillation (AF) ablation. Recently, different operators have combined a single transseptal puncture technique with 3D high-density mapping catheters for pulmonary vein isolation (PVI). Objective: This study aims to compare two strategies, single vs. double TSP, regarding the duration of the procedure, radiation time, complication rates, and outcomes. Methods: Retrospective analysis of a large cohort of consecutive patients that underwent first PVI with radiofrequency energy (RF), using a point-by-point strategy, with a 3D mapping system, either with single or double TSP, according to the operator's choice. Results: 285 patients with a mean age of 59.5 ± 11.6 years (36.5% female, 67.7% paroxysmal AF) underwent a point-by-point catheter ablation with RF between July 2015 and March 2020. The mean CHA2DS2-VASc score was 1.7 ± 1.3. Single TSP was performed in 115 (40.3%) patients and double TSP in 170 (59.6%). The operator's experience (≥5 years of AF ablation procedures) was equally distributed among the two groups. The average procedure time (133 ± 31.7 min vs. 123 ± 35.5 min, for single and double TSP, respectively) did reach a statistical difference between both groups (p = 0.008), but there was a substantial advantage regarding fluoroscopy time (13 ± 6.3 min vs. 19 ± 9.1 min, for single and double TSP, respectively; p < 0.001). Acute major complications present similar rates in both groups (2.6% vs. 2.3%, p = 0.799). At the 2-year follow-up, both groups had a similar sinus rhythm maintenance rate (76.5% vs. 78.8%, p = 0.646). Conclusion: A simplified single-TSP technique using high-density multi-electrode 3D mapping is a safe and highly successful option for AF ablation. This approach yields a substantial reduction in fluoroscopy time, with the potential to avoid acute complications, compared to a conventional double-TSP strategy.

Validation of a Heart Failure Risk Score in a Cohort of Cardiac Resynchronization Therapy Patients Under Remote Monitoring: Results from the TriageHF™ Algorithm.

The heart failure risk status (HFRS) is a validated dynamic tool for risk score prediction, based on the TriageHF™ algorithm (Medtronic, Minneapolis, MN, USA), for the occurrence of a heart failure (HF) event in the 30 days following a remote monitoring (RM) transmission. The aim of this study was to evaluate the accuracy of the HFRS in predicting an unplanned hospital admission due to HF decompensation in a real-world cohort of patients submitted to cardiac resynchronization therapy (CRT). We conducted a single-center review of a cohort of 40 consecutive HF patients, under RM, with CRT devices using the HFRS of the TriageHF™ algorithm. The correlation of the HFRS with hospital admissions was analyzed. During a mean follow-up of 36 months, a stepwise increase in the HFRS was significantly associated with a higher risk of HF admission (odds ratio, 12.7; 95% confidence interval, 3.2-51.5; P < .001), and the HFRS was demonstrated to have good discrimination for HF hospitalization, with an area under the receiver-operating characteristic curve of 0.812. The TriageHF™ algorithm effectively predicted HF-related hospitalization in a cohort of CRT patients during long-term RM follow-up, providing a novel clinical pathway to optimize the clinical management of this complex population.