bluuebunny/crossref_metadata_2025 huggingface dataset:
Resonant Tunnelling Diode – Photodetectors for spiking neural networks
Authors: Lourenço J , Al-Taai Q R , Al-Khalidi A , Wasige E , Figueiredo J
Published: December 2022

Spike-based neuromorphic devices promise to alleviate the energy greed of the artificial intelligence hardware by using spiking neural networks (SNNs), which employ neuron like units to process information through the timing of the spikes. These neuron-like devices only consume energy when active. Recent works have shown that resonant tunnelling diodes (RTDs) incorporating optoelectronic functionalities such as photodetection and light emission can play a major role on photonic SNNs. RTDs are devices that display an N-shaped current-voltage characteristics capable of providing negative differential conductance (NDC) over a range of the operating voltages. Specifically, RTD photodetectors (RTD-PDs) show promise due to their unique mixture of the structural simplicity while simultaneously providing highly complex non-linear behavior. The goal of this work is to present a systematic study of the how the thickness of the RTD-PD light absorption layers (100, 250, 500 nm) and the device size impacts on the performance of InGaAs RTD-PDs, namely on its responsivity and time response when operating in the third (1550 nm) optical transmission window. Our focus is on the overall characterization of the device optoelectronic response including the impact of the light absorption on the device static current-voltage characteristic, the responsivity and the photodetection time response. For the static characterization, the devices I-V curves were measured under dark conditions and under illumination, giving insights on the light induced I-V tunability effect. The RTD-PD responsivity was compared to the response of a commercial photodetector. The characterization of the temporal response included its capacity to generate optical induced neuronal-like electrical spike, that is, when working as an opto-to-electrical spike converter. The experimental data obtained at each characterization phase is being used for the evaluation and refinement of a behavioral model for RTD-PD devices under construction.
Plasmonic/magnetic liposomes based on nanoparticles with multicore-shell architecture for chemo/thermotherapy
Authors: Rodrigues Ana Rita O. , Santos Lia C. A. , Macedo Daniela O. , Rio Irina S. R. , Pires Ana , Pereira André M. , Arújo João P. , Castanheira Elisabete M. S. , Coutinho Paulo J. G.
Published: December 2022

Multifunctional nanosystems are capable to carry one or more therapeutic agents (thermal and/or targeting agents and chemotherapeutic drugs), offering the capability to concurrently perform different treatment modalities using a single nanosystem. Cluster nanostructures, consisting of densely packed aggregates of magnetic nanoparticles, have shown enhanced heating capabilities. Their combination with plasmonic nanoparticles enable synergistic behavior between dual hyperthermia (magneto-photothermia), allowing overheating cancer cells while increasing drug toxicity. In this work, multicore magnetic nanoparticles (NPs) of MnFe2O4 were prepared using oxamide and melamine as clustering agents. The multicore NPs prepared with oxamide were covered with a gold shell, resulting in multicore magnetic/plasmonic NPs with an increased SAR of 173.80 W/g, under NIR light. Liposomes based on these magnetic/plasmonic NPs were prepared and the model drug curcumin was loaded in these nanocarriers with a high encapsulation efficiency. The fusion between the curcumin-loaded magnetic/plasmonic liposomes and models of cell membranes (labelled with Nile Red) was confirmed by FRET, pointing the magneto/plasmonic liposomes as promising for dual cancer therapy (combined hyperthermia and chemotherapy).
Design and test results of different aluminum coating layers on the sCMOS sensors for soft X-ray detection
Authors: Wang W.X. , Ling Z.X. , Zhang C. , Yuan W.M. , Zhang S.N.
Published: December 2022

In recent years, tremendous progress has been made on complementary metal-oxide-semiconductor (CMOS) sensors for applications as X-ray detectors. To shield the visible light in X-ray detection, a blocking filter of aluminum is commonly employed. We designed three types of aluminum coating layers, which are deposited directly on the surface of back-illuminated sCMOS sensors during fabrication. A commercial 2k × 2k sCMOS sensor is used to realize these designs. In this work, we report their performance by comparison with that of an uncoated sCMOS sensor. The optical transmissions at 660 nm and 850 nm are measured, and the results show that the optical transmission reaches a level of about 10-9 for the 200 nm aluminum layer and about 10-4 for the 100 nm aluminum layer. Light leakage is found around the four sides of the sensor. The readout noise, fixed-pattern noise and energy resolution of these Al-coated sCMOS sensors do not show significant changes. The dark currents of these Al-coated sCMOS sensors show a noticeable increase compared with that of the uncoated sCMOS sensor at room temperatures, while no significant difference is found when the sCMOS sensors are cooled down to about -15°C. The aluminum coatings show no visible crack after the thermal cycle and aging tests. Based on these results, an aluminum coating of a larger area on larger sCMOS sensors is proposed for future work.
Weakening seasonality of Indo-Pacific warm pool size in a warming world since 1950
Authors: Gan Qiuying , Leung Jeremy Cheuk-Hin , Wang Lei , Zhang Banglin
Published: December 2022

Seasonal variation of the Indo-Pacific warm pool (IPWP) plays an important role in oceanographic and climatological processes. While expansion of the IPWP under greenhouse warming has been widely discussed, the response of IPWP seasonality to climate change has received limited attention. In this study, we found an obvious seasonal diversity in expansion of the IPWP from 1950 to 2020, with a maximum (minimum) expansion trend of 0.28

×

107 km2/decade in winter (0.17

×

107 km2/decade in spring), which consequently reduces the seasonality amplitude of the variation in IPWP size. This is primarily attributed to the seasonal difference in the climatological spatial sea surface temperature (SST) pattern over the Indo-Pacific Ocean, especially that over the tropical Indian Ocean, which determines the capacity for IPWP expansion. Heat budget analyses show that the seasonal shortwave radiation and latent heat fluxes are the major factors controlling the capacity for change in IPWP size across seasons. The presented analyses emphasize the significant weakening of the seasonality of IPWP size, which may have great impacts on the ecological environment of the IPWP and the tropical climate system, and remind us that the intrinsic properties of the climate background of Indo-Pacific SST hold important clues about IPWP expansion under climate change.
Linking repeat lidar with Landsat products for large scale quantification of fire-induced permafrost thaw settlement in interior Alaska
Authors: Zhang Caiyun , Douglas Thomas A , Brodylo David , Jorgenson M Torre
Published: December 2022

The permafrost–fire–climate system has been a hotspot in research for decades under a warming climate scenario. Surface vegetation plays a dominant role in protecting permafrost from summer warmth, thus, any alteration of vegetation structure, particularly following severe wildfires, can cause dramatic top–down thaw. A challenge in understanding this is to quantify fire-induced thaw settlement at large scales (>1000 km2). In this study, we explored the potential of using Landsat products for a large-scale estimation of fire-induced thaw settlement across a well-studied area representative of ice-rich lowland permafrost in interior Alaska. Six large fires have affected ∼1250 km2 of the area since 2000. We first identified the linkage of fires, burn severity, and land cover response, and then developed an object-based machine learning ensemble approach to estimate fire-induced thaw settlement by relating airborne repeat lidar data to Landsat products. The model delineated thaw settlement patterns across the six fire scars and explained ∼65% of the variance in lidar-detected elevation change. Our results indicate a combined application of airborne repeat lidar and Landsat products is a valuable tool for large scale quantification of fire-induced thaw settlement.
Combined impact of summer NAO and northern Russian shortwave cloud radiative effect on Eurasian atmospheric circulation
Authors: Liu Le , Wu Bingyi , Ding Shuoyi
Published: December 2022

Based on ERA-Interim and CERES_SYN1deg Ed4.1 datasets, the combined influence of summer North Atlantic Oscillation (SNAO) and positive shortwave cloud radiative effect (SWCRE) events in northern Russia on Eurasian atmospheric circulation is investigated at the intraseasonal scale. The impact of the SNAO on the position of the North Atlantic storm track is modified combined with the Ural anticyclone anomaly contributed by positive northern Russian SWCRE anomalies, which could affect the summer stationary wave pattern. During positive northern Russian SWCRE events under SNAO+, the upstream wave train enhanced by the southward Ural anticyclone anomaly is easily trapped by the northward South Asian jets, thus propagating to low latitudes and causing extreme heat events in East Asia. Under SNAO-, the wave train propagates in the British–Baikal Corridor pattern along polar front jet towards the Far East, slowing down the dramatic melting of sea ice in the Laptev and East Siberian seas. Summer positive SWCRE events in northern Russian act as a bridge by promoting the emergence of the Ural anticyclone anomaly, influencing extreme weather in East Asia and Arctic sea ice variability.
Objective Analysis of Breast Symmetry in Female Patients Undergoing Breast Reconstruction After Total Mastectomy
Authors: Sampathkumar Urmila , Bui Thao , Liu Jun , Nowroolizarki Zhale , Bordes Mary Catherine , Hanson Summer E , Reece Gregory P , Markey Mia K , Merchant Fatima A
Published: December 2022

Background

Satisfaction with the breast aesthetic outcome is an expectation of breast reconstruction surgery, which is an integral part of cancer treatment for many patients. We evaluated postreconstruction breast symmetry in 82 female patients using distance and volume measurements.

Objectives

Clinical factors, such as reconstruction type (implant-based and autologous reconstruction), laterality, timing of reconstruction (immediate, delayed, and sequential), radiation therapy (RT), and demographic factors (age, BMI, race, and ethnicity), were evaluated as predictors of postoperative symmetry. Matched preoperative and postoperative measurements for a subset of 46 patients were used to assess correlation between preoperative and postoperative symmetry.

Methods

We used standardized differences between the left and right breasts for the sternal notch to lowest visible point distance and breast volume as metrics for breast, positional symmetry, and volume symmetry, respectively. We performed statistical tests to compare symmetry between subgroups of patients based on reconstruction type, laterality, timing, RT, and demographics.

Results

Overall, reconstruction type, reconstruction timing, and RT were observed to be factors significantly associated with postoperative symmetry, with implant reconstructions and immediate reconstruction procedures, and no RT showing better postoperative breast volume symmetry. Subgroup analyses, for both reconstruction type and laterality, showed superior volume symmetry for the bilateral implant reconstructions. No correlation was observed between preoperative and postoperative breast symmetry. Demographic factors were not significant predictors of postreconstruction symmetry.

Conclusions

This comprehensive analysis examines multiple clinical factors in a single study and will help both patients and surgeons make informed decisions about reconstruction options at their disposal.

Level of Evidence: 3
Insane in the vembrane: filtering and transforming VCF/BCF files
Authors: Hartmann Till , Schröder Christopher , Kuthe Elias , Lähnemann David , Köster Johannes
Published: December 2022

We present vembrane as a command line variant call format (VCF)/binary call format (BCF) filtering tool that consolidates and extends the filtering functionality of previous software to meet any imaginable filtering use case. Vembrane exposes the VCF/BCF file type specification and its inofficial extensions by the annotation tools VEP and SnpEff as Python data structures. vembrane filter enables filtration by Python expressions, requiring only basic knowledge of the Python programming language. vembrane table allows users to generate tables from subsets of annotations or functions thereof. Finally, it is fast, by using pysam and relying on lazy evaluation.

Availability and implementation

Source code and installation instructions are available at github.com/vembrane/vembrane (doi: 10.5281/zenodo.7003981).

Supplementary information

Supplementary data are available at Bioinformatics online.
The effects of 105 biological, socioeconomic, behavioral, and environmental factors on the risk of SARS-CoV-2 infection and a severe course of COVID-19: a prospective, explorative cohort study
Authors: Flegr Jaroslav , Flegr Pavel , Příplatová Lenka
Published: December 2022

The confirmed number of SARS-CoV-2 infections up to 18 October 2022 is 626 million worldwide, but information about factors affecting the probability of infection or a severe course of COVID-19 remains insufficient and often speculative. Only a small number of factors have been rigorously examined, mostly by retrospective or cross-sectional studies.

 

We ran a preregistered study on 5164 Internet users who shared information with us about their exposure to 105 risk factors and reported being COVID-19 negative before the beginning of the fourth wave of COVID-19 in the Czech Republic. After the fourth wave, in which 709 (13.7%) of participants were infected, we used a partial Kendall test controlled for sex, age, and urbanization to compare the risk of infection and a severe course of the disease in subjects who initially did and did not report exposure to particular risk factors.

 

After the correction for multiple tests, we identified 13 factors – including male sex, lower age, blood group B, and larger household size – that increased the risk of infection and 16 factors – including mask-wearing, borreliosis in the past, use of vitamin D supplements, or rooibos drinking – that decreased it. We also identified 23 factors that increased the risk of a severe course of COVID-19 and 12 factors that decreased the risk.

 

This preregistered longitudinal study is of explorative nature. Therefore, although the observed effects were strong and remained highly significant even after correction for multiple tests, it will be necessary to confirm their existence in future independent studies.
Improved prediction of new COVID-19 cases using a simple vector autoregressive model: evidence from seven New York state counties
Authors: Kitaoka Takayoshi , Takahashi Harutaka
Published: December 2022

With the rapid spread of COVID-19, there is an urgent need for a framework to accurately predict COVID-19 transmission. Recent epidemiological studies have found that a prominent feature of COVID-19 is its ability to be transmitted before symptoms occur, which is generally not the case for seasonal influenza and severe acute respiratory syndrome. Several COVID-19 predictive epidemiological models have been proposed; however, they share a common drawback – they are unable to capture the unique asymptomatic nature of COVID-19 transmission. Here, we propose vector autoregression (VAR) as an epidemiological county-level prediction model that captures this unique aspect of COVID-19 transmission by introducing newly infected cases in other counties as lagged explanatory variables. Using the number of new COVID-19 cases in seven New York State counties, we predicted new COVID-19 cases in the counties over the next 4 weeks. We then compared our prediction results with those of 11 other state-of-the-art prediction models proposed by leading research institutes and academic groups. The results showed that VAR prediction is superior to other epidemiological prediction models in terms of the root mean square error of prediction. Thus, we strongly recommend the simple VAR model as a framework to accurately predict COVID-19 transmission.
Progression and interventional therapy of a coronary pseudoaneurysm: a case report
Authors: Gersch Svante , Baraki Hassina , Toischer Karl
Published: December 2022

Background

Coronary pseudoaneurysms (PSAs) occur as a rare complication following drug-eluting stent implantation and have been reported to occur between 1 week and 4 years after implantation. Most of them remain in a stable state, but progression of PSAs increases the risk of rupture and haemorrhagic cardiac tamponade.

Case summary

Here, we present a case of a 55-year-old patient, who developed a PSA of the proximal left circumflex artery after stent implantation of the left main artery, left anterior descending artery, and left circumflex artery. Within <1 year, the patient was readmitted to different hospitals due to cardiac decompensation and myocardial infarction. Thereafter, coronary angiography and computed tomography scans were performed, and progression of the PSA could be documented. Interventional therapy was chosen due to the high surgical risk of the patient. Implantation of a covered stent from the left main artery into the left anterior descending artery was chosen to treat the PSA, thereby silencing the chronically occluded left circumflex artery, followed by dilatation with a non-compliant balloon. The patient has remained asymptomatic in a 6-month follow-up.

Discussion

Coronary PSA should be controlled with respect to progression, and appropriate therapy can be chosen for treatment.
402 A SIMPLIFIED ECHOCARDIOGRAPHIC FORMULA TO ESTIMATE CARDIAC INDEX IN THE INTENSIVE CARE UNIT
Authors: Gaspardone Carlo , Romagnolo Davide , Baldetti Luca , Fasolino Alessandro , Peveri Beatrice , Calvo Francesco , Gramegna Mario , Pazzanese Vittorio , Sacchi Stefania , Beneduce Alessandro , Falasconi Giulio , Fiore Giorgio , Rampa Lorenzo , Ajello Silvia , Mara Scandroglio Anna
Published: December 2022

Background and aim

Measurement of cardiac index (CI) is crucial in the hemodynamic assessment of critically ill patients in the intensive care unit (ICU). The most reliable trans-thoracic echocardiography (TTE) technique for CI estimation is the left ventricular outflow tract (LVOT) Doppler method that requires, among other parameters, the LVOT cross-sectional area (CSA) measurement. However, geometrical assumptions inherent limitations and practical disadvantages related to the ICU setting, hamper LVOT-CSA assessment. In this study, we aimed to validate a simplified formula, leveraging only on LVOT-velocity time integral (VTI) and heart rate (HR) variables, for the non-invasive estimation of CI in ICU patients.

Methods and Results

We prospectively enrolled 50 consecutive patients admitted to our ICU requiring PAC over a one-year period. For each patient we measured the CI by PAC (CIPAC) and TTE. The latter was obtained both with the “traditional formula” (traditional CITTE), requiring LVOT-CSA assessment, and our new “simplified formula” (simplified CITTE). The correlation between the simplified CITTE and CIPAC was strong (r = 0.81) and resulted significantly greater than the traditional CITTE and CIPAC correlation (r = 0.70; p < 0.05 for Pearson r coefficients comparison). Both TTE-based CI showed an acceptable agreement (+0.19±0.48 L/min/m2 for simplified CITTE and -0.18±0.58 L/min/m2 for traditional CITTE) with the reference CIPAC.

Conclusion

In this study, we propose an easy-to-use and practical approach, leveraging on TTE LVOT-VTI and HR only, for non-invasive estimation of CI in ICU patients.
986 LEFT VENTRICULAR LEAD PLACEMENT FOR BIVENTRICULAR PACING INTO A LEFT LATERAL VEIN IN PATIENT WITH CONGENITAL ATRESIA OF THE CORONARY SINUS OSTIUM WHO UNDERWENT AORTIC VALVE REPLACEMENT
Authors: Santoro Amato , Barilli Maria , Marallo Carmine , Cameli Matteo
Published: December 2022

Introduction

Coronary sinus ostial atresia (CSOA) is a rare congenital heart anomaly consisting in the occlusion of the coronary sinus (CS) outlet in the right atrium. It is one of the causes of placement left lead failure in CS during cardiac resynchronization therapy (CRT) device implantation. The persistence of the left superior vena cava is the most common pathway that allows venous blood flow to drain into the right atrium and can represent a new possible way to reach a left ventricular vein from the CS.

Methods

A 66-year-old male suffering from sarcoidosis was studied after an episode of syncope under exertion. EKG showed a 1st degree atrioventricular block and a left bundle branch block (LBBB) with wide QRS (170 ms). Echocardiography found left ventricle dilatation, severe systolic dysfunction, and a severe low-flow low-gradient aortic stenosis for which he underwent aortic valve replacement. After surgery and finding of 2nd degree type II atrioventricular block, CRT implant was performed but the procedure was complicated by the finding of CSOA. The insertion of the left quadripolar lead along a left branch of the occluded CS was achieved with a push-and-pull technique of the lead over a guidewire, after the retrieval and the cannulation of the persistent left superior vena cava.

Results

A new approach was applied on a rare case of CSOA found during CRT procedure. The contrast medium (CM) in the left subclavian vein revealed the existence of the left superior vena cava that was than cannulated. CM injection in CS highlighted a posterior left branch that was approached with a specific guidewire and a subselector after selective venography. With a fine technique of sliding of the lead on a tensioned guidewire, the quadripolar catheter was successfully placed in the left ventricular vein. Left-ventricle-right ventricle delays and catheter thresholds were tested and a final QSR duration of 90 msec in CRT mode was obtained.

Conclusions

This case-report shows a complex technique, reported in parallel with other similar procedures, to help the approach toward a rare anatomical variant of CSOA accompanied by persistent left superior vena cava when a CRT implant is needed after cardiac valve surgery in a patient suffering from sarcoidosis.
925 THE TWIDDLER'S SYNDROME: A CASE REPORT
Authors: Campana Nicola , Licciardi Marco , Pinna Gabriele , Soro Cinzia , Sara Santus , Mohammad Ahmad , Nissardi Vincenzo , Piras Alessandra , Cadeddu Dessalvi Christian , Roberta Montisci
Published: December 2022

Introduction

The Twiddler's syndrome is a rare condition of malfunctioning of a cardiovascular implantable elettronic device (CIED) due to the rotation of the device around its own long axis within its pocket. This brings to the leads wrapping around the device case and consequently dislocating, resulting in a deficit in sensing and pacing.

Case Report

We present the case of an 82-year-old woman, affect by atrial and conduction tissue disease for which was implanted a dual-chamber PaceMaker (PM). She arrived at the emergency department for asthenia and a traumatic syncopal episode, preceded by intense general malaise, nausea and vomiting. At EKG findings of electroinduced atrial rhythm, electroinduced ventricular rhythm with loss of capture and emergence of spontaneous rhythm, with subsequent resumption of capture. At device telemetry check, rise of ventricular and atrial pacing thresholds together with sporadic ventricular capture losses. Chest×Ray showed entanglement of leads around the PM case and retraction of the ventricular catheter.

Therefore, the patient was admitted to the cardiology department, and the surgical pocket was revised with case extraction and leads debridement with subsequent optimization of their position. The next day, following device telemetry check, which showed good electrical parameters, and the follow-up chest X-Ray, which was normal, the patient was discharged.

Conclusion

All physicians, particularly cardiologists, must pay close attention to the evaluation of patients with CIEDs. First of all, meticulous analysis of the EKG must be performed, which is capable of showing loss of capture and abnormal QRS morphologies due to cardiac pacing at abnormal locations. In addition, it is necessary to perform the telemetry check of the device, infact findings of sensing deficits and/or elevation of pacing thresholds indicate device malfunctioning, which is not necessarily due to leads injuries. Displacement of the leads can be easily detected with a chest X-ray, always remembering to rule out the presence of Twiddler syndrome, however rare it may be.
765 PULSED FIELD ABLATION FOR PULMONARY VEIN ISOLATION: PRELIMINARY RESULTS OF A SINGLE CENTER EXPERIENCE
Authors: Capone Silvia , Cauti Filippo Maria , Rossi Pietro , Magnocavallo Michele , Polselli Marco , Bianchi Stefano
Published: December 2022

Background

Pulsed Field Ablation (PFA) is a new and promising non-thermal ablation modality for Pulmonary Vein Isolation (PVI) for the treatment of patients with Atrial Fibrillation (AF). It preferentially ablates myocardial tissue via electroporation leading to minimal effects on surrounding structures. We sought to evaluate safety and efficacy of PFA in our single center experience.

Methods

PFA was performed at optimized bipolar biphasic waveform using Farapulse system. A protocol of 8 pulses per vein, 4 in the basket configuration and 4 in the flower configuration was followed. The procedure was performed under general anesthesia. Fluoroscopy was used to guide single transseptal puncture. 1 mg of atropine was administered before starting applications. One third of patients underwent CTI ablation using radiofrequency during the same procedure. In one patient we mapped the left atrium before and after ablation using a high-density mapping catheter.

Results

We prospectively enrolled 21 patients (76% men, age 58,6 ± 9) who underwent PVI using PFA from July to September 2022 for the treatment of Paroxysmal AF (81%) or Persistent AF (19%). Acute pulmonary veins isolation was achieved in the totality of patients. Median skin-to-skin procedure time and catheter dwell time were 56 minutes and 29 minutes respectively. Median fluoroscopy time was 12 minutes. The average number of total applications was 34 ± 4. No adverse events were observed. After a median follow-up of 77 days, we observed early AF recurrence in two patients.

Conclusion

Preliminary results of our singe center experience confirm that PFA is a safe and effective ablation modality. Pulmonary vein isolation can be achieved very rapidly with short procedural time, catheter dwell time and fluoroscopy time. Further studies are needed to assess durability of the technique.
651 ZERO FLUOROSCOPY CARDIAC ABLATION: A NOVEL WORKFLOW FOR ATRIAL FIBRILLATION
Authors: Raffele Martina De , Bertini Matteo , Malagu´ Michele , Vitali Francesco , Balla Cristina , Pompei Graziella , Fiorio Alessio , Trichilo Michele , Guardigli Gabriele
Published: December 2022

Background and Rationale

A fluoroscopy-based approach to an electrophysiological procedure is widely validated and has been recognized as the gold standard for a long time. The use of fluoroscopy exposes both the healthcare staff and the patient to a non-negligible dose of radiation. To minimize the risks associated with the use of fluoroscopy, it would be reasonable to perform ablation procedures with zero fluoroscopy. This approach is widely used in simple ablation procedures, but not in complex procedures. In atrial fibrillation (AF) ablation procedures, fluoroscopy remains the main technology used, particularly to guide the transseptal puncture.

Main results and Implications

We present a workflow to perform a complete zero-fluoroscopy ablation for AF ablation procedures using a 3D electro-anatomical mapping system, intracardiac echocardiography and a novel steerable guiding sheath that can be visualized on the mapping system. We present two AF ablation procedures, one performed on a patient with paroxysmal AF (Fig.1) and one with persistent AF (Fig. 2, Fig 3) during which we applied this novel workflow, achieving a successful pulmonary vein isolation without complications and complete zero-fluoroscopy exposure.
571 SUCCESSFUL PERMANENT PACEMAKER IMPLANTATION IN A PATIENT WITH DEXTROCARDIA AND SITUS INVERSUS TOTALIS: LOOKING AT THE MIRROR.
Authors: Paolantonio Diana Di , Guida Giuseppina , Caravati Fabrizio , Ponti Roberto De
Published: December 2022

Background

Dextrocardia is a rare congenital condition with a prevalence of 0.83 per 10000 pregnancies. Its most common configuration is situs inversus totalis, also known as “mirror-image dextrocardia”. This case report presents a clinical case of symptomatic sinus node dysfunction requiring permanent pacemaker implantation (PPI) in a patient with mirror-image dextrocardia.

Case summary

A 81-year-old female patient with known situs inversus totalis presented with recurrent syncope. Sick sinus syndrome was diagnosed after documentation of critical pauses (>6.3”) at 24-hour Holter monitoring, giving indication to elective PPI.

At admission, 12-lead ECG showed sinus bradycardia and right axis deviation on the frontal plane (standard peripheral leads position and precordial leads on the right side of the chest).

Transthoracic echocardiography was performed prior to the procedure with the ultrasound probe flipped and placed on the patient's right side of the thorax, thus achieving standard echocardiography windows and images. A preserved biventricular systolic function and the absence of relevant valvular disease or cardiac malformations was documented.

The next day, a dual-chamber pacemaker was implanted following standard technique with the operator standing on the right side of the patient and with right subclavian vein puncture; the pacemaker pocket was created in the right pectoral region. The entire procedure was performed under fluoroscopic guidance using horizontally 180° flipped views, therefore obtaining identical images to those of standard PPI procedures, helping the operator identify anatomical structures during lead positioning. [Fig. 1 a - b]

Chest X-ray confirmed correct pacemaker lead placement and absence of procedure-related complications. Stable and satisfactory lead parameters were observed at follow-up.

Discussion

In literature there are only a few case reports on PPI in situs inversus totalis. The symmetrical disposition of the anatomy makes transvenous PPI technically demanding. In this case the challenge was overcome by using flipped fluoroscopy images, to facilitate lead positioning maneuvres. This technique can be considered only in situs inversus totalis and not in other forms of dextrocardia, such as dextroversion and destroposition, because it is the only situation in which the anatomy is the mirror image of the normal one.
226 ECHOCARDIOGRAPHIC AND INVASIVE EVALUATION OF LEFT ATRIAL PRESSURE IN PATIENTS UNDERGOING CATHETER ABLATION FOR ATRIAL FIBRILLATION
Authors: Bonelli Andrea , Inciardi Riccardo Maria , Cersosimo Angelica , Dell´era Gabriele , Degiovanni Anna , Spinoni Enrico , Bosco Manuel , Arabia Gianmarco , Salghetti Francesca , Bellicini Mariagiulia , Brangi Elisa , Legati Michele , Pagnesi Matteo , Lombardi Carlo Mario , Curnis Antonio , Patti Giuseppe , Metra Marco
Published: December 2022

Aims

Estimation of left ventricle (LV) filling pressure is one of the most important parameters to provide information in clinical practice. However, the challenging in investigating this parameter through invasive methods makes it difficult to be used. The study aims to investigate the association between cardiac structure and function derived by transthoracic echocardiography (TTE) and left atrial (LA) invasive pressure (LAP).

Methods

The study was a multi-center prospective study enrolling 73 patients (mean age 65 ± 8, 27% female) undergoing primary catheter ablation for AF. Patients were evaluated and enrolled from June 2021 to April 2022. Complete TTE assessing measures of LV, LA and right ventricle (RV) structure and function including speckle tracking echocardiography, was performed at baseline.

Echocardiographic data have been assessed the same day of the invasive measurement of the LAP during AF ablative procedure. Linear regression analysis has been performed to assess the relationship between measures of cardiac structure and function and LAP. Logistic regression analysis assessed the parameters associated with elevated LAP (≥ 15mmHg).

Results

Baseline clinical characteristics of the study population did not differ according to elevated LAP vs. non-elevated LAP. Patients with elevated LAP showed instead abnormal measures of LV global longitudinal strain, measures of LA structure and function, except for LA maximal volume, and RV structure and function. After multivariable adjustment, including demographic factors and comorbidities, E/e`(p = 0,024), LA minimal volume (p = 0,009), LA emptying fraction (LAEF) (p = 0,012), LA Reservoir (p = 0,039), TAPSE (p = 0,010) and RV free wall strain (p = 0,028), but not LA maximal volume (p = 0,11), were significantly associated with LAP. Similarly, these measures, but nor LA maximal volume, were significant determinants of elevated LAP. Overall, LA minimal volume and LAEF showed the best diagnostic accuracy to predict elevated LAP (AUC 0.72 and 0.73, respectively).

Conclusions

Novel measures of LA structure and function, but not standard assessment by LA maximal volume, were significantly associated with LAP in patients affected by AF. These measures, along with measures of LV and RV function may be used in the diagnostic assessment of filling pressure in ambulatory settings.
892 ELECTRICAL STORM IN ISCHAEMIC HEART DISEASE: A CASE OF LEFT STELLATE GANGLION BLOCK AS BRIDGE TO URGENT PCI RESCUE
Authors: Mancini Nastasia , Crea Pasquale , Dattilo Giuseppe , Costa Francesco , Vizzari Giampiero , Baldi Enrico , Luzza Francesco , Carerj Scipione , Micari Antonio , Di Bella Gianluca
Published: December 2022

A 73 year-old man was admitted for syncope and sustained ventricular arrhythmia complicated by cardiogenic shock treated with electrical cardioversion and restoration of sinus rhythm.

Former smoker, he suffered by arterial hypertension, hypercholesterolemia and known heart failure with reduced ejection fraction. In the 1995 the patient underwent aortic valve replacement surgery with a mechanical prosthetic valve. The patient underwent coronary angiography that showed multivessel coronary artery disease with functional occlusion of posterior interventricular artery (rehabilitated by hetero-coronary circles) and critical stenosis of the middle left anterior descending artery. In this angiographic framework, the indication was collegial revaluation considering other patient's comorbidities (chronic renal dysfunction, mitral moderate-severe regurgitation). The patient underwent ICD implantation for secondary prevention.

Despite maximal medical therapy, the patient experienced new episodes of sustained VT complicated by hemodynamic instability. Hypokalemia, hypomagnesemia and hyperthyroidism were excluded as triggering factors for arrhythmias on laboratory investigations. In the following days due to persistent and symptomatic arrhythmias, configuring electrical storm, we decided to proceed with anatomical stellate ganglion block, guarantying a free interval from ventricular arrhythmia about six hours. The anesthetic has been injected at the C6 or C7 vertebral level with the Chassignac's tubercle, the cricoid cartilage, and the carotid artery serving as the anatomic landmarks to the procedure. An aspiration test must be done to avoid the suction of blood or cerebrospinal fluid, then a local anesthetic is injected, and the diffusion of the injectate is seen in real-time. Local anesthetic (lidocaine mixed with bupivacaine) is injected until the fluid spread along the paravertebral fascia to the stellate ganglion. The period free from VA allowed us to transfer the patient in another center in order to receive myocardial revascularization supported by ECMO. Left ganglion stellate block has a central role in the treatment of the refractory ventricular arrhythmias and may offer effective arrhythmia control giving time to rescue and/or other bridge therapy. In our case, it had a key role to perform an inter-hospital transfer and subsequent “rescue PCI therapy”. Thanks to Stellate ganglion block, the sinus rhythm was retained immediately, there were no ventricular tachycardia episodes for at least six hours allowing to perform myocardial revascularization supported by ECMO. No further ventricular arrhythmias occurred after revascularization, corroborating the ischemic trigger of electrical storm.
756 ZERO OR NEAR ZERO FLUOROSCOPY CATHETER ABLATION OF PREMATURE VENTRICULAR CONTRACTIONS: A MULTICENTRE EXPERIENCE
Authors: Mugnai Giacomo , Velagic Vedran , De Asmundis Carlo , Malagù Michele , Tomasi Luca , Bolzan Bruna , Chierchia Gian-battista , Stroker Erwin , Bertini Matteo
Published: December 2022

Background

Catheter ablation has become an established treatment option for premature ventricular complexes (PVCs). It is well known that the use of fluoroscopy exposes patients and medical staff to potentially harmful stochastic and deterministic effects of ionising radiations.

We sought to analyse procedural outcomes in terms of safety and efficacy using a “zero” or “near zero” X rays approach for treatment of PVCs.

Methods

The present retrospective, multicentre, observational study included 131 patients having undergone catheter ablation of PVCs using zero or “near zero” (less than 2 minutes) fluoroscopy between 2016 and 2020 in 4 high-volume centres. Baseline characteristics of the population, acute success and complications derived from the procedure were evaluated, as well as recurrence rate during follow-up.

Results

Median age was 51.0 years old [38-63], males were 77 (58.8%). Most often cause of ablation were palpitations (90.0%), followed by reduced left ventricular ejection fraction (4.6%) and pre-syncope (14.5%). Among the study population, 26 (19.8%) had a cardiopathy. The median PVC burden before ablation was 15.1% [6%-22.4%]. The most frequent PVC origin was right ventricular outflow tract (n=72; 55.0%) followed by the left ventricle (n=21; 16.0%), LVOT and cusps (n=18; 13.7%),aortomitral continuity (n=7; 5.3%).

A 3D electro-anatomical mapping system was used in all cases as well as a contact force catheter for mapping and ablation. The mean maximum radiofrequency power applied was 32.9 ± 4.1 W (median time: 370 sec). Median number of applications was 4.5 and mean total procedural time was 117.3 ± 47.5 minutes. Median best prematurity was 31.5 msec. We used isoprenaline in order to induce PVCs in 42% of cases and suppression of PVC was achieved in 127 patients (96.9%). There was only 2 complication (femoral hematoma and arteriovenous fistula conservatively treated). At 12 months, a complete success was documented in 109 patients (83.2%), a reduction in PVC burden was achieved in other 18 patients (13.7%) and a failure was recorded in 4 patients (3.1%).

Conclusion

The PVC ablation with “zero” or “near-zero” fluoroscopy is a safe procedure with no major complications and good rates of success and recurrence in our multicentre experience.
193 13 SECONDS OF ASYSTOLE IN YOUNG: IS A PACEMAKER NECESSARY?
Authors: Petrungaro Mattia , Berton Giampaolo , Scarà Antonio , Borrelli Alessio , Latorre Maria , Ruvo Ermenegildo De , Sciarra Luigi , Calò Leonardo
Published: December 2022

Introduction

Cardioinhibitory neurocardiogenic syncope (CNS) is caused by inappropriately trigger-activated cardiac reflex which finally precipitates asystole, sinus bradycardia, or atrioventricular block. In the absence of structural heart disease, the prognosis is excellent, but frequent syncopal episodes can have a significant impact on quality of life. No medical therapy has proved to be really effective and studies concerning pacemaker implantation are often controversial. However, in young individuals, especially those under 40 years of age, implanting a pacemaker may carry more risks than benefits. Thus, alternative techniques such as ablation of the cardiac atrial parasympathetic ganglia (GP) have emerged.

Case report

A 34-year-old man with frequent episodes of reflex syncope performed a tilt test in March 2022 that diagnosed cardio-inhibitory syncope with 13-second asystole interrupted with external cardiac massage and intravenous atropine. In May 2022 he had an MRI scan showing normal biventricular systolic function and absence of late-gadolinium enhancement and underwent loop recorder implantation. He came to our centre in June 2022 and underwent electrophysiological study and electroanatomical mapping of the right atrium (Carto 3) during general anaesthesia. The anatomical areas of the supero-posterior and infero-posterior GPs of the right atrium were identified by electroanatomical mapping of complex fractionated atrial electrograms (CFAE). Radiofrequency pulses (Thermocool 30 watts) were delivered at these points, resulting in the disappearance of the CFAEs and an increase in basal heart rate. The greatest number of ganglia are allocated on the posterior surface of the right atrium and in particular the supero-posterior GP is the nexus point for vagal input to the GPs before innervating the atria. Therefore, it was decided to localise and ablate exclusively the GPs of the right atrium. The procedure was completed without complications. The patient has not complained of any syncopal episodes since, and the loop has not recorded any significant pauses.

Conclusions

The anatomic ablation of GP only in the right atrium could represent a feasible method to reduce CNS, to increase the warning symptoms period, and to delay as much as possible pacemaker implant, especially in young patients who have experienced a related physical trauma. This approach significantly decreased the procedural time and risks.
181 SAFETY AND EFFICACY OF SUBCUTANEOUS IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS LEAD REMOVAL: A SINGLE CENTER EXPERIENCE
Authors: Pittorru Raimondo , Bernardo Dall´aglio Pietro , Valerio Falzone Pasquale , Giacomin Lazzari Enrico , De Manuel , Iliceto Sabino , Migliore Federico
Published: December 2022

The aim of this monocentric experience was to evaluate the efficacy and safety of subcutaneous implantable cardioverter-defibrillators (S-ICDs) lead removal procedures.

Background

S-ICD represents a therapeutic option for patients at high-risk of sudden cardiac death, in whom pacing or cardiac resynchronization therapy is not required. Furthermore, S-ICD is a suitable alternative in patients who had underwent to transvenous lead extraction, expecially to limit lead-related complications of transvenous ICD. However, data are lacking about the safety and feasibility of S-ICD lead removal procedures.

Methods

We enrolled a population consisted of 11 consecutive patients requiring S-ICD lead removal between May 25, 2014, and June 26, 2022. The primary endpoint of the study was procedural success, defined as the removal of all the lead and lead material from the subcutaneous space. Secondary endpoints included procedural complications and the need for specific removal tools.

Results

S-ICD lead removal procedures were performed in 11 patients (mean age 47 ± 14, 82% men, 64% in primary prevention). Indications for S-ICD removal procedures were replace with inappropriate sensing (n=2), generator and lead infection (n= 3), pocket erosion (n=1), system malfunction (n=2), ineffective therapy (n=1) and, finally, heart transplantation (n=2). The median time from S-ICD lead implantation to S-ICD removal was 16 (6-38) months. The primary endpoint was achieved in 100% of the patients, without procedural failure. Simple traction of the S-ICD lead was successful in 8 patients (73%), whereas 3 patients (27%) required non-powered mechanical sheath to remove lead adhesions around the coil. No addictional incision were needed in order to lead removal. No procedure-related complications occurred. Patients with device infection underwent to S-ICD removal earlier than patients without (11 months [6.5 to 15.2 months ] vs 31 months [16.5 to 45.5 months]).

Conclusions

Although simple manual traction is effective in most patients, additional tools are required in few cases, raising the question, if also the S-ICD lead removal should performed in centers with lead extraction experience with available advanced tools.
621 TRANSVENOUS LEAD ADVANCEMENT IN PAEDIATRIC PACING TO OVERCOME GROWTH STRETCHING
Authors: Porco Luigina , Silvetti Massimo Stefano , Cicenia Marianna , Tamburri Ilaria , Silvetti Giacomo , Campisi Marta , Saputo Fabio Anselmo , Battista Virginia , Drago Fabrizio
Published: December 2022

Background

One of the main complications of transvenous leads implanted in paediatric patients is the stretching of the lead caused by the somatic growth. It may cause pacing and sensing defects and lead dislodgement or even fracture. Absorbable lead ligature and atrial loop may reduce this risk. However, the loop may induce traction or may unroll too early and therefore impair lead function. Lead extraction and replacement is another solution, although it has some procedural risks in young patients. Lead advancement through pushing it from the pocket may solve growth-induced traction and spare the electrode throughout childhood until post-puberty.

Objective

of the study is the retrospective analysis of the outcome of the transvenous lead advancement in children with a pacemaker (PM) in a single tertiary paediatric center.

Methods

consecutive patients with a VVIR PM implanted for isolated congenital complete atrioventricular block (no structural heart disease) in alternative right ventricular (RV) pacing sites, with lead stretching underwent a trial of lead advancement during general anaesthesia, cefuroxime antibiotic profilaxis, from 2014 to 2021. After venous angiography showed venous patency, the PM pocket was opened, the lead was released from subcutaneous adherences and with a stylet was gently advanced to create a semi-loop in the atrium without dislodging the tip. Lead data (threshold, sensing, impedance) were compared before and after the procedure. Data are expressed as median (25th-75th centiles).

Results

8 patients underwent PM implantation at 6.8 (5.8-8.0) years of age, 20 (18-21) kg, 116 (106-120) cm, with the lead positioned at parahisian(3)/mid-septum (5 pts) sites. During a follow-up of 3 (1-5) years, advancement procedures were 1.5 (1.0-4.3) per patient. Between procedures, delta age was 16 (12-20) months, height 8 (7-11) cm and weight 5 (3-7) kg. All leads were successfully advanced without any procedural complications. Procedure time (skin to skin) was 96 (73-108) minutes, fluoroscopy was 0.5 (0.2-1.4) mGy, 16 (10-46) microGy/m2. Electrical lead parameters did not showed significant differences between consecutive control times.

Conclusion

the advancement of transvenous leads in children is a safe and effective procedure, with low fluoroscopy exposure, without significant acute and chronic complications. This procedure seems to preserve transvenous leads until growth has completed.