High-fidelity glass micro-axicons fabricated by laser-assisted wet etching.

We report on the fabrication of micro-axicons made of glass by laser-assisted wet etching (LAE) and laser polishing. The employed technique, relying on a direct-writing process using a femtosecond laser, allows revealing high fidelity profiles when the exposed glass samples are etched in a heated potassium hydroxide (KOH) solution. The remaining surface roughness is then decreased by carbon dioxide (CO2) laser polishing. Such polishing is limited to the superficial layer of the component so that the tip is only slightly rounded, with a radius of curvature of nearly 200 µm. It is then shown with 500 µm-diameter axicons that a quasi-Bessel beam is generated closely after the tip and features a 5.3 µm diameter maintained over a propagation distance of almost 3.5 mm.

An autopsy view of the Hemi-commando procedure.

Invasive endocarditis involving the fibrous skeleton of the heart requires complex high-risk surgical management. For combined aortic and mitral infection in whom the posterior mitral leaflet and at least the free edge of anterior mitral valve could be spared, a modification of the Commando procedure was suggested: the "Hemi-commando procedure." We report the autopsy images of a Hemi-commando procedure after in unfortunate death in a 24 years old man 17 days after surgery.

Real-time Lissajous imaging with a low-voltage 2-axis MEMS scanner based on electrothermal actuation.

Laser scanning based on Micro-Electro-Mechanical Systems (MEMS) scanners has become very attractive for biomedical endoscopic imaging, such as confocal microscopy or Optical Coherence Tomography (OCT). These scanners are required to be fast to achieve real-time image reconstruction while working at low actuation voltage to comply with medical standards. In this context, we report a 2-axis Micro-Electro-Mechanical Systems (MEMS) electrothermal micro-scannercapable of imaging large fields of view at high frame rates, e.g. from 10 to 80 frames per second. For this purpose, Lissajous scan parameters are chosen to provide the optimal image quality within the scanner capabilities and the sampling rate limit, resulting from the limited A-scan rate of typical swept-sources used for OCT. Images of 233 px × 203 px and 53 px × 53 px at 10 fps and 61 fps, respectively, are experimentally obtained and demonstrate the potential of this micro-scannerfor high definition and high frame rate endoscopic Lissajous imaging.

Right atrial catheter "ghost" removal by cardiac surgery: A pediatric case series report.

Fibrin sheath formation around long-term indwelling central venous catheters is common and usually benign. Fibrin sheath can persist after catheter removal and rarely leads to complications. This is a report of three pediatric oncology patients that required cardiac surgery for cardiac embolization of a "ghost" catheter several years after catheter removal. One case required tricuspid valve replacement for complete tricuspid valve destruction and two had erosion through the atrial wall. The severity of these rare complications mandates follow-up of "ghost" catheters in pediatric oncology patients.

First-Degree Relatives Screening of Patients with Bicuspid Aortic Valve: Effectiveness and Feasibility in Pediatric Cardiology Daily Practice.

Bicuspid aortic valve (BAV) is the most common congenital heart disease. Since heritability is suspected, actual guidelines recommend to perform an echocardiographic assessment for first-degree relatives (FDR) of patient with BAV. This study aimed to assess the effectiveness and the feasibility of the current guidelines for the screening of FDR of patient with BAV in a pediatric cardiology daily practice. Consecutive patients with BAV and their FDR were prospectively included from January 2015 to March 2018 at Centre Hospitalier Universitaire de Laval, Quebec City (Canada). Data were retrospectively collected and analyzed. A total of 713 FDR of 213 consecutives index cases [median age: 11 (6-20) years] were studied. Up to 32 (6.6%) FDR had a BAV and 26 (5.4%) had an aortic valve dysfunction. A total of 14 (2.9%) FDR had an ascending aorta dilatation according to Z-score including 6 (1.2%) patients with an ascending aorta ≥ 45 mm. No statistically significant differences regarding BAV, aortic valve dysfunction and ascending aorta dilatation prevalence were identified between generations. Screening was done in 482 (67.6%), prescribed but not done in 134 (19%), not prescribed in 92 (13%) and declined in 5 (1%) FDR. The prevalence of BAV in FDR was similar to prospective adult studies and supports actual guidelines in pediatric cardiology practice. Ascending aorta dilatation was rare in our young population. Exhaustiveness and additional burden to implement current guidelines remain a challenge in daily practice.

Wafer-level vapor cells filled with laser-actuated hermetic seals for integrated atomic devices.

Atomic devices such as atomic clocks and optically-pumped magnetometers rely on the interrogation of atoms contained in a cell whose inner content has to meet high standards of purity and accuracy. Glass-blowing techniques and craftsmanship have evolved over many decades to achieve such standards in macroscopic vapor cells. With the emergence of chip-scale atomic devices, the need for miniaturization and mass fabrication has led to the adoption of microfabrication techniques to make millimeter-scale vapor cells. However, many shortcomings remain and no process has been able to match the quality and versatility of glass-blown cells. Here, we introduce a novel approach to structure, fill and seal microfabricated vapor cells inspired from the century-old approach of glass-blowing, through opening and closing single-use zero-leak microfabricated valves. These valves are actuated exclusively by laser, and operate in the same way as the "make-seals" and "break-seals" found in the filling apparatus of traditional cells. Such structures are employed to fill cesium vapor cells at the wafer-level. The make-seal structure consists of a glass membrane that can be locally heated and deflected to seal a microchannel. The break-seal is obtained by breaching a silicon wall between cavities. This new approach allows adapting processes previously restricted to glass-blown cells. It can also be extended to vacuum microelectronics and vacuum-packaging of micro-electro-mechanical systems (MEMS) devices.

Diagnostic Efficacy of a Single-Lead Ambulatory 14-Day ECG Monitor in Symptomatic Children.

BACKGROUND: The CardioSTAT is a single-lead ambulatory electrocardiography monitor that has been validated for use in adult patients. Recording is made through 2 electrodes positioned in a lead-I configuration, and the device allows monitoring for 2, 7, or 14 days. We sought to investigate the efficacy of this device in children with paroxysmal palpitations. METHODS: In phase I, the quality of tracings from simultaneous CardioSTAT recordings and D1-lead recordings of a standard 12-lead electrocardiography machine in 23 children were compared. Phase II was a prospective observational cohort study comparing arrhythmia detection using the CardioSTAT vs currently used devices (24-hour Holter monitor and the Cardiomemo loop recorder) in 52 children complaining of palpitations. RESULTS: In Phase I, all but 3 rhythm strips were correctly identified. The pacing spikes on 3 strips were not adequately identified by the observers for the CardioSTAT recording. In Phase II, symptomatic episodes were reported in 42%, 73%, and 100% of subjects during monitoring with the Holter, Cardiomemo, and CardioSTATdevices, respectively. An abnormal rhythm was detected in 13%, 23%, and 35% of subjects by the Holter, Cardiomemo, and CardioSTAT monitors, respectively. The underlying rhythm during symptomatic events was determined in 90% of cases with the CardioSTAT monitor, whereas it was determined in only 19% and 29% of cases using the Holter and Cardiomemo monitors, respectively. CONCLUSIONS: The CardioSTAT monitor provided good-quality tracings and was superior to the 24-hour Holter monitor and the Cardiomemo loop recorder in determining the presence or absence of pathologic arrhythmia in the study cohort.

CONTEXTE: Le CardioSTAT est un moniteur d'électrocardiographie ambulatoire à dérivation unique dont l'utilisation a été validée chez les patients adultes. L'enregistrement se fait au moyen de 2 électrodes positionnées dans une configuration de type « dérivation I ¼, et l'appareil permet un suivi pendant 2, 7 ou 14 jours. Nous avons cherché à étudier l'efficacité de cet appareil chez les enfants atteints de palpitations paroxystiques. MÉTHODOLOGIE: Dans la phase I, la qualité des tracés provenant d'enregistrements simultanés de CardioSTAT et d'enregistrements de la dérivation I d'un appareil d'électrocardiographie standard à 12 dérivations a été comparée chez 23 enfants. La phase II était une étude de cohorte observationnelle prospective comparant la détection de l'arythmie à l'aide du moniteur CardioSTAT par rapport aux appareils utilisés actuellement (moniteur Holter à surveillance sur 24 heures et enregistreur d'événements portatif Cardiomémo) chez 52 enfants se plaignant de palpitations. RÉSULTATS: Dans la phase I, toutes les bandes d'enregistrement sauf trois ont été correctement identifiées. Les spicules de stimulation n'ont pas été correctement détectés par les observateurs sur trois bandes d'enregistrement du moniteur CardioSTAT. Dans la phase II, des épisodes symptomatiques ont été signalés chez 42 %, 73 % et 100 % des sujets pendant la surveillance avec les appareils Holter, Cardiomémo et CardioSTAT, respectivement. Un rythme anormal a été détecté chez 13 %, 23 % et 35 % des sujets par les moniteurs Holter, Cardiomémo et CardioSTAT, respectivement. Le rythme sous-jacent pendant les événements symptomatiques a été déterminé dans 90 % des cas avec le moniteur CardioSTAT, alors qu'il n'a été déterminé que dans 19 % et 29 % des cas, respectivement, avec les moniteurs Holter et Cardiomémo. CONCLUSIONS: Le moniteur CardioSTAT a fourni des tracés de bonne qualité et s'est révélé supérieur à l'appareil Holter à surveillance sur 24 heures et à l'enregistreur d'événements portatif Cardiomémo pour déterminer la présence ou l'absence d'arythmie pathologique dans la cohorte étudiée.

Transcatheter closure of patent foramen ovale in patients older than 60 years of age with cryptogenic embolism.

INTRODUCTION AND OBJECTIVES: Randomized trials have shown the efficacy of transcatheter closure of patent foramen ovale (PFO) in patients aged ≤ 60 years with cryptogenic embolism. We aimed to assess the long-term safety and efficacy of PFO closure in patients aged> 60 years. METHODS: Of 475 consecutive patients with cryptogenic embolism who underwent PFO closure, 90 older patients aged> 60 years (mean, 66±5 years) were compared with 385 younger patients aged ≤ 60 years (mean, 44±10 years). RESULTS: Older patients had a higher prevalence of cardiovascular risk factors (CVRF) (hypertension, dyslipidemia, diabetes; P <.01 for all vs younger patients). There were no differences in periprocedural complications between the 2 groups. During a median follow-up of 8 (4-12) years, there were a total of 17 deaths, all from noncardiovascular causes (7.8% and 2.6% in the older and younger patient groups, respectively; HR, 4.12; 95%CI, 1.56-10.89). Four patients had a recurrent stroke (2.2% and 0.5% in the older and younger patient groups, respectively; HR, 5.08; 95%CI, 0.71-36.2), and 12 patients had a transient ischemic attack (TIA) (3.3% and 2.3% in the older and younger patient groups, respectively; HR, 1.71; 95%CI, 0.46-6.39). There was a trend toward a higher rate of the composite of stroke/TIA in older patients (5.5% vs 2.6%; HR, 2.62; 95%CI, 0.89-7.75; P=.081), which did not persist after adjustment for CVRF (HR, 1.97; 95%CI, 0.59-6.56; P=.269). CONCLUSIONS: In older patients with cryptogenic embolism, PFO closure was safe and associated with a low rate of ischemic events at long-term. However, older patients exhibited a tendency toward a higher incidence of recurrent stroke/TIA compared with younger patients, likely related to a higher burden of CVRF.

More Than 25 Years of Experience With the Ross Procedure in Children: A Single-Center Experience.

BACKGROUND: Aortic valve replacement in children represents an important challenge. Concerns regarding pulmonary autograft and homograft longevity requiring reoperations are well recognized. Very long-term outcomes after the Ross procedure are still unknown. We reviewed our experience with the Ross procedure, aiming to define very long-term survival rate and freedom from reintervention. METHODS: This was a single-center retrospective cohort including 63 consecutive children who underwent the Ross procedure. Median follow-up duration was 20.5 years. Time-related events were assessed using Kaplan-Meier estimator. RESULTS: There were 51 (81%) boys, mean age 10.1 ± 5.8 years. Isolated aortic stenosis was the most common diagnosis (n = 29, 46%) and 34 (54%) patients previously underwent cardiac surgery. There was 1 (1.6%) in-hospital death. Overall survival at 5, 15, and 25 years was 96.7%, 94.4%, and 94.4%, respectively. Freedom from any autograft-related reintervention was 98.1%, 86.4%, and 61.2% at 5, 15, and 25 years, respectively. Fifteen (24%) patients underwent autograft reoperations. Among them, 10 (67%) patients underwent valve-sparing autograft reoperation. Freedom from any pulmonary conduit reintervention was 93.2%, 58.2%, and 28.3% at 5, 15, and 25 years, respectively. Thirty (46.6%) patients underwent conduit reintervention (8 percutaneous, 22 surgical replacements). CONCLUSIONS: The pediatric Ross procedure is associated with excellent long-term survival. Ross-related reinterventions are more than twice as common on the pulmonary homograft than on the autograft.

Dipole states and coherent interaction in surface-acoustic-wave coupled phononic resonators.

Manipulation of mechanical motion at the micro-scale has been attracting continuous attention, leading to the successful implementation of various strategies with potential impact on classical and quantum information processing. We propose an approach based on the interplay between a pair of localised mechanical resonators and travelling surface acoustic waves (SAW). We demonstrate the existence of a two-sided interaction, allowing the use of SAW to trigger and control the resonator oscillation, and to manipulate the elastic energy distribution on the substrate through resonator coupling. Observation of the vectorial structure of the resonator motion reveals the existence of two coupling regimes, a dipole-dipole-like interaction at small separation distance versus a surface-mediated mechanical coupling at larger separation. These results illustrate the potential of this platform for coherent control of mechanical vibration at a resonator level, and reciprocally for manipulating SAW propagation using sub-wavelength elements.

Neonatal Cardiac Arrest From Left Ventricular Cardiac Hemangioma: A Surprising Presentation.

Cardiac hemangioma is rare, even more when leading to a cardiovascular collapse in a seemingly healthy newborn. A 6-day-old neonate had a tamponade caused by a basolateral hemangioma of the left ventricle. Partial surgical resection was performed. A congenital lobular capillary hemangioma was diagnosed upon histologic examination. The patient recovered completely and shows normal development at the 12-month follow-up.

Impact of Discontinuation of Antithrombotic Therapy Following Closure of Patent Foramen Ovale in Patients With Cryptogenic Embolism.

No data exist on the optimal duration of antithrombotic therapy (AT) following patent foramen ovale (PFO) closure. We sought to assess the safety of AT discontinuation following PFO closure in patients with a cryptogenic ischemic event. A total of 453 consecutive patients (mean age: 48 ± 13years, men: 51%) who underwent PFO closure due to a cryptogenic ischemic event were included. All patients were on AT following PFO closure (antiplatelet therapy: 92.7%, anticoagulation: 7.3%). Ischemic and bleeding events, and AT were assessed at a median follow-up of 8 (IQR: 4 to 11) years, and follow-up was complete in 96% of patients. Stroke and transient ischemic attack occurred in 4 (0.9%) and 12 (2.6%) patients, respectively, and 27 (6.0%) patients had bleeding events (major in 6 [1.3%] patients, including 4 episodes of intracranial hemorrhage). All major bleeding events occurred under aspirin therapy. A total of 82 patients (18%) stopped the AT at a median of 7 (IQR: 5 to 34) months post-PFO closure (due to a bleeding event or gastrointestinal symptoms: 13 patients, no specific reason: 69 patients), and none of them had any ischemic event after a median time of 7 (IQR 3 to 10) years without any AT. A propensity score matched analysis including 46 patients who discontinued the AT within 1-year post-PFO closure and 120 patients with an ongoing AT showed the lack of differences in ischemic events between groups (0 vs 0.2 stroke/transient ischemic attack per 100 patient-years in the no-AT and AT groups, respectively). In conclusion, in young patients who underwent PFO closure, bleeding events occurred in ∼6% of patients after a median follow-up of 8years. AT was discontinued in about one fifth of patients (most of them within the year following PFO closure), and this was not associated with any increase in ischemic events at long-term follow-up. These results suggest that, in patients without other co-morbidities increasing the risk of stroke, temporary AT following PFO closure may be a reasonable strategy.

Long-Term Follow-Up After Closure of Patent Foramen Ovale in Patients With Cryptogenic Embolism.

BACKGROUND: Patent foramen ovale (PFO) closure is the gold standard for treating patients with cryptogenic stroke and PFO. However, scarce data exist on the long-term outcomes following PFO closure. OBJECTIVES: The purpose of this study was to determine the long-term (>10 years) clinical outcomes (death, ischemic, hemorrhagic events) following transcatheter PFO closure. METHODS: We included 201 consecutive patients (mean age: 47 ± 12 years, 51% women) who underwent PFO closure due to a cryptogenic embolism (stroke: 76%, transient ischemic attack [TIA]: 32%, systemic embolism: 1%). Echocardiographic examinations were performed at 1- to 6-month follow-up. Ischemic and bleeding events and antithrombotic medication were collected at a median follow-up of 12 years (range 10 to 17 years), and follow-up was complete in 96% of the patients. RESULTS: The PFO closure device was successfully implanted in all cases, and residual shunt was observed in 3.3% of patients at follow-up echocardiography. A total of 13 patients died at follow-up (all from noncardiovascular causes), and nondisabling stroke and TIA occurred in 2 and 6 patients, respectively (0.08 strokes per 100 patient-years; 0.26 TIAs per 100 patient-years). A history of thrombophilia (present in 15% of patients) tended to associate with a higher rate of ischemic events at follow-up (p = 0.067). Bleeding events occurred in 13 patients and were major (intracranial bleeding) in 4 patients (all of them under aspirin therapy at the time of the event). A total of 42 patients stopped the antithrombotic treatment at a median of 6 months (interquartile range 6 to 14 months) post-PFO closure, and none of them had any ischemic or bleeding episode after a mean of 10 ± 4 years following treatment cessation. CONCLUSIONS: PFO closure was associated with a low rate of ischemic events (stroke, 1%) at >10 years of follow-up. Major bleeding events occurred in 2% of the patients (all of them in patients on antiplatelet therapy). One-fifth of patients stopped the antithrombotic therapy during the follow-up period (the majority within the first-year post-PFO closure), and this was not associated with any increase in ischemic events at long-term follow-up.

Incidence, timing, and predictive factors of new-onset migraine headache attack after transcatheter closure of atrial septal defect or patent foramen ovale.

The objectives of this study were to evaluate the incidence, predictive factors, and duration of migraine headache attack (MHA) after transcatheter atrial septal defect (ASD) or patent foramen ovale (PFO) closure. A total of 260 consecutive patients who underwent ASD or PFO closure in our center answered a structured headache questionnaire focused in 3 period times, including (1) at baseline (just before closure), (2) within the 3 months after ASD-PFO closure, and (3) at the last (median 27 months, range 6 to 80 months) follow-up. All questionnaires were evaluated by a neurologist who established the diagnosis of MHA with or without aura, according to International Headache Society criteria. The Amplatzer ASD or PFO device was used in 95% of the patients, and aspirin, for at least 6 months, was the antithrombotic treatment in 91% of the cases. A total of 185 patients (71%) had no history of MHA before ASD-PFO closure, and these constituted the study population (mean age 39 +/- 21 years). MHA occurred in 13 patients (7%) after ASD-PFO closure, with aura in 9 of them. MHA appeared after a median of 10 days (range 0.3 to 30 days) after the procedure and were still present at the last follow-up (23 +/- 17 months) in 9 patients (69%). The median number of MHA within the 3 months after the procedure was 4 per month (interquartile range 1 to 23), and decreased to 1 per month (interquartile range 0.3 to 1) at the latest follow-up (p = 0.03). Compared with the patients who did not develop MHA, patients with MHA after ASD-PFO closure were younger (26 +/- 16 vs 39 +/- 21 years; p = 0.02) and were more likely to have undergone ASD closure (100% vs 58%; p = 0.001). In the multivariate analysis, ASD closure was the only predictor of MHA occurrence after the procedure (odds ratio 7.7; 95% confidence interval 1.5 to 22; p = 0.01). In conclusion, MHA, mostly with aura, occurred in 7% of patients after transcatheter ASD-PFO closure and persisted in most of them after a mean follow-up of 2 years. ASD closure was the only independent predictor of MHA occurrence after the procedure. These results suggest that mechanisms other than device composition are involved in the occurrence of MHA in these cases.

Transvenous pacing leads and systemic thromboemboli in patients with intracardiac shunts: a multicenter study.

BACKGROUND: The risk of systemic thromboemboli associated with transvenous leads in the presence of an intracardiac shunt is currently unknown. METHODS AND RESULTS: To define this risk, we conducted a multicenter, retrospective cohort study of 202 patients with intracardiac shunts: Sixty-four had transvenous leads (group 1), 56 had epicardial leads (group 2), and 82 had right-to-left shunts but no pacemaker or implantable cardioverter defibrillator leads (group 3). Patient-years were accrued until the occurrence of systemic thromboemboli or study termination. Censoring occurred in the event of complete shunt closure, death, or loss to follow-up. Mean ages for groups 1, 2, and 3 were 33.9+/-18.0, 22.2+/-12.6, and 22.9+/-15.0 years, respectively. Respective oxygen saturations were 91.2+/-9.1%, 88.1+/-8.1%, and 79.7+/-6.7%. During respective median follow-ups of 7.3, 9.3, and 17.0 years, 24 patients had at least 1 systemic thromboembolus: 10 (15.6%), 5 (8.9%), and 9 (11.0%) in groups 1, 2, and 3, respectively. Univariate risk factors were older age (hazard ratio [HR], 1.05; P=0.0001), ongoing phlebotomy (HR, 3.1; P=0.0415), and an transvenous lead (HR, 2.4; P=0.0421). In multivariate, stepwise regression analyses, transvenous leads remained an independent predictor of systemic thromboemboli (HR, 2.6; P=0.0265). In patients with transvenous leads, independent risk factors were older age (HR, 1.05; P=0.0080), atrial fibrillation or flutter (HR, 6.7; P=0.0214), and ongoing phlebotomy (HR, 14.4; P=0.0349). Having had aspirin or warfarin prescribed was not protective. Epicardial leads were, however, associated with higher atrial (P=0.0407) and ventricular (P=0.0270) thresholds and shorter generator longevity (HR, 1.9; P=0.0176). CONCLUSIONS: Transvenous leads incur a >2-fold increased risk of systemic thromboemboli in patients with intracardiac shunts.

Enhanced thrombogenesis but not platelet activation is associated with transcatheter closure of patent foramen ovale in patients with cryptogenic stroke.

BACKGROUND AND PURPOSE: No studies have yet determined whether antiplatelet or anticoagulant therapy is the more appropriate treatment after transcatheter closure of patent foramen ovale (PFO) in patients with cryptogenic stroke. The objective of this study was to prospectively evaluate the presence, degree, and timing of activation of the platelet and coagulation systems after transcatheter closure of PFO in patients with cryptogenic stroke. METHODS: Twenty-four consecutive patients (mean age, 44+/-10 years; 11 men) with previous cryptogenic stroke who had undergone successful transcatheter closure of PFO were included in the study. Prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin III (TAT) were used as markers of coagulation activation, and soluble P-selectin and soluble CD40 ligand were used as markers of platelet activation. Measurements of all hemostatic markers were taken at baseline just before the procedure and at 7, 30, and 90 days after device implantation. RESULTS: F1+2 and TAT levels increased from 0.41+/-0.16 nmol/L and 2.34+/-1.81 ng/mL, respectively, at baseline to a maximal value of 0.61+/-0.16 nmol/L and 4.34+/-1.83 ng/mL, respectively, at 7 days, gradually returning to baseline levels at 90 days (P<0.001 for both markers). F1+2 and TAT levels at 7 days after PFO closure were higher than those obtained in a group of 25 healthy controls (P<0.001 for both markers). Levels of soluble P-selectin and soluble CD40 ligand did not change at any time after PFO closure. CONCLUSIONS: Transcatheter closure of PFO is associated with significant activation of the coagulation system, with no increase in platelet activation markers. These findings raise the question of whether optimal antithrombotic treatment after PFO closure should be short-term anticoagulant rather than antiplatelet therapy.

Catheter ablation for cardiac arrhythmias: a 14-year experience with 5330 consecutive patients at the Quebec Heart Institute, Laval Hospital.

BACKGROUND: Catheter ablation is a curative treatment with excellent success and minimal complication rates for patients with supraventricular or ventricular arrhythmias. METHODS: The acute outcomes and complications of all catheter ablation procedures for supraventricular and ventricular arrhythmias performed at the Quebec Heart Institute (Sainte-Foy, Quebec) during a 14-year period from January 1, 1993, to December 31, 2006, were prospectively assessed. The ablation procedures were classified according to the arrhythmias induced using standard electrophysiological techniques and definitions. Immediate success and complication rates were prospectively included in the database. RESULTS: A total of 5330 patients had catheter ablation performed at the Institute during the period assessed. The mean (+/- SD) age of patients was 50 +/- 18 years (range four to 97 years), and 2340 patients (44%) were men. Most of the patients were younger than 75 years (group 1), and 487 (9%) were 75 years of age and older (group 2). Indications for ablations were as follows: atrioventricular nodal re-entry tachycardia (AVNRT) in 2263 patients, accessory pathways in 1147 patients, atrioventricular node ablation in 803 patients, typical atrial flutter in 377 patients and atrial tachycardia in 160 patients; 580 patients had other ablation procedures. The overall success rates were 81% for atrial tachycardia, 92% for accessory pathways or flutter, and 99% for AVNRT or atrioventricular node ablation. There was no difference in the success rates of the younger (group 1) and older (group 2) patients. Seventy-seven patients (1.4%) had complications, including 11 major events (myocardial infarction in one patient, pulmonary embolism in three patients and permanent pacemaker in seven patients). In patients undergoing AVNRT ablation, two had a permanent pacemaker implanted immediately after the procedure and three had a permanent pacemaker implanted at follow-up. CONCLUSIONS: The results confirm that radiofrequency ablation is safe and effective, supporting ablation therapy as a first-line therapy for the majority of patients with cardiac arrhythmias.

In situ electrical resistivity measurements of vanadium thin films performed in vacuum during different annealing cycles.

The present study describes a sputtering and in situ vacuum electrical resistivity setup that allows a more efficient sputtering-oxidation coupling process for the fabrication of oxide compounds like vanadium dioxide, VO2. After the sputtering deposition of pure V thin films, the proposed setup enables the sample holder to be transferred from the sputtering to the in situ annealing + resistivity chamber without venting the whole system. The thermal oxidation of the V films was studied by implementing two different temperature cycles up to 550 °C, both in air (using a different resistivity setup) and vacuum conditions. Main results show that the proposed system is able to accurately follow the different temperature setpoints, presenting clean and low-noise resistivity curves. Furthermore, it is possible to identify the formation of different vanadium oxide phases in air, taking into account the distinct temperature cycles used. The metallic-like electrical properties of the annealed coatings are maintained in vacuum whereas those heated in air produce a vanadium oxide phase mixture.