Satisfactory Pacing Research Articles

Leadless pacemaker implementation at the right atrial appendage apex: An initial preclinical assessment.

This study evaluates the feasibility and efficacy of implanting a leadless pacemaker at the right atrial appendage (RAA) in a preclinical minipig model, aiming to address the limitations of atrial pacing with current leadless devices like the Medtronic Micra, which is typically used for right ventricular implantation. Four minipigs, each with a median body weight of 45.8±10.0kg, underwent placement of the Micra transcatheter pacing system (TPS) via the right femoral vein into the RAA apex. The pacing performance was assessed over 1-week (short-term) and 3-month (long-term) periods. The initial findings indicated successful implantation, with satisfactory intrinsic R-wave amplitudes and pacing threshold. In the following period, the sensitivity, threshold, and impedance were stable with time. Notably, upon explanation at 3 months, a deep myocardial penetration by the device was observed, necessitating a redesign for safe long-term use in a growing subject's heart. While initial results suggest that RAA apex placement of the Micra TPS is promising for potential inclusion in a dual-chamber pacing system, the issue of myocardial penetration highlights the need for device redesign to ensure safety and effectiveness in long-term applications.

New-generation Leadless Pacemaker Implantation: First Procedures in Central Asia.

In this article, we describe our first experiences implanting the AVEIR VR leadless pacemaker (Abbott) in Kazakhstani patients, a significant step in the development of this technology in Central Asia. This case series includes five male patients, with a range of symptoms (presyncope, dizziness and dyspnoea on exertion), ranging in age from 14 to 77 years; some individuals also had comorbidities, including atrioventricular block and AF. Indications for pacing were identified in each patient. The parameters of postimplantation stimulation and the results of initial observations were recorded. The procedure was quite successful and radiographic confirmation of the location of the leadless pacemaker was obtained. All patients demonstrated clinical improvement and satisfactory pacing parameters at early follow-up. The potential of the AVEIR leadless pacemaker to minimise lead insertion complications has been demonstrated, with no immediate complications observed in the patients in this study.

Development status evaluation and path analysis of regional clean energy power generation in China

Due to differences in resource endowments, levels of economic development, energy structure, and effects of policy implementation, the level of clean energy development in different regions in China is nonuniform. To achieve carbon peaking and carbon neutrality, it is necessary to clarify the law of clean energy development and formulate policies tailored to local conditions. Based on relevant data on clean energy power, this paper establishes a system for evaluating the levels of clean energy development in each region in China by the entropy method and quantitatively analyzes the key factors influencing regional clean energy development. Based on this, the development characteristics of clean energy in different regions are discussed, and four historical paths for developing clean energy are summarized. The findings reveal the following: (1) overall, clean energy development in most regions in China is proceeding at a satisfactory pace. The contribution of resource endowment to clean energy development is considerable in Southwest and Northwest China. (2) The paths involved in the regional development of clean energy can be categorized into rising, declining, stable, and fluctuating types. (3) Currently, clean energy development in China remains largely dependent on resource endowments and is restricted by the capacity of traditional large-scale energy generation units. (4) In the foreseeable future, a sound and effective trading mechanism for the clean energy market will play an important role in economically developed regions and promote a higher level of development and generation of clean energy.

A Study to Analyse the Feasibility and Effectiveness of Left Bundle Branch Area Pacing Used in Young Children.

This study aimed to investigate the feasibility and effectiveness of left bundle branch area pacing (LBBaP) in young children. From September 2020 to May 2021, a total of 31 children (≤ 7years) with complete atrioventricular block were included. All patients were scheduled to undergo LBBaP. Pacing parameters, and cardiac function and synchrony were evaluated during follow-up. LBBaP succeeded in 21 children (3.3 ± 2.1years old), with a success rate of 70.9%. LBBaP failed in nine children, who eventually received right ventricular septal pacing (RVSP). The average postoperative QRS duration in patients of LBBaP group was narrower than that of RVSP group: 100.9 ± 9.1 versus 114.2 ± 11.9ms (P = 0.002). The median follow-up duration was 12 [interquartile range (IQR) 6-15] months. At last time of follow-up, the capture threshold of ventricular electrode in patients of LBBaP group were significantly lower than that of RVSP group (0.70 ± 0.25 versus 1.39 ± 0.94V, P = 0.011). The echo-left ventricular ejection fraction (LVEF) in patients in the LBBaP group was better than that in the RVSP group (66.1 ± 3.3 versus 63.1 ± 2.2%, P = 0.025). LBBaP can be safely and effectively administered in young children. Satisfactory pacing parameters, andnarrow QRS durations were obtained.

Economic complexity of cities and its role for resilience.

The aim of the paper is to propose the construction of an index that captures the economic complexity of cities over the globe, as well as to explore whether it is a good predictor for a range of city-level economic outcomes. This index aspires to mitigate data scarcity for cities and to provide policy makers with the tools for monitoring the evolving role of cities in the global economy. Analytically, we implement the economic complexity methodology on data for the ownership, location and economic activities of the world’s 3,000 largest firms and their subsidiaries to propose a new indicator that quantifies the network of the largest cities worldwide and the economic activities of their globalized firms. We first show that complex cities are the highly diversified cities that host non-ubiquitous economic activities of firms with global presence. Then, in a sample of EU cities, we show that complex cities tend to be more prosperous, have higher population, and are associated with more jobs, human capital, innovation, technology and transport infrastructure. Last, using OLS methodology and accounting for several other confounders, we show that a higher ECI, at the city level, enhances the resilience of cities to negative economic shocks, i.e., their ability to bounce back after a shock. Specifically, we find that the expected increase of the ratio of employment in 2012 over 2006 is 0.01 (mean: 0.992; standard deviation: 0.081) when the ECI increases by 1 unit (mean: 0.371; standard deviation: 1.094), i.e., a satisfactory pace of recovery, in terms of employment. The ability to diversify in the presence of a shock, the reallocation of factors of production to other sectors and the ability to extract rents associated with those diversified activities, uncovers the mechanics of the ECI index.

Initial Experience with Left Bundle Branch Area Pacing with Conventional Stylet-Driven Extendable Screw-In Leads and New Pre-Shaped Delivery Sheaths.

Until recently, left bundle branch area pacing (LBBAp) has mostly been performed using lumen-less fixed screw leads. There are limited data on LBBAp with conventional style-driven extendable screw-in (SDES) leads, particularly data performed by operators with no previous experience with LBBAp procedures. In total, 42 consecutive patients undergoing LBBAp using SDES leads and newly designed delivery sheaths (LBBAp group) were compared with those treated with conventional right ventricular pacing (RVp) for atrioventricular block (RVp group, n = 84) using propensity score matching (1:2 ratio). The LBBAp was successful in 83% (35/42) of patients, with satisfactory pacing thresholds (0.8 ± 0.2 V at 0.4 ms). In the LBBAp group, the mean paced-QRS duration obtained during RV apical pacing (173 ± 18 ms) was significantly reduced by LBBAp (116 ± 14 ms, p < 0.001). Compared with the RVp group, the LBBAp group showed more physiological pacing, suggested by a much narrower paced-QRS duration (116 ± 14 vs. 151 ± 21 ms, p < 0.001). The pacing threshold was comparable in both groups. The LBBAp group revealed stable pacing thresholds for 6.8 ± 4.8 months post-implant and no serious complications including lead dislodgement or septal perforation. The novel approach of LBBAp using SDES leads and the new dedicated pre-shaped delivery sheaths was effectively and safely performed, even by inexperienced operators with LBBAp procedures.

Multi-clad optical fiber design for ultra-wideband modulation instability

Developments of electro-optic (EO) modulators do not have a satisfactory pace and bandwidth restrictions are still limited to several hundred GHz, thus, obtaining methods that enable using broadband optical channels are key factors in high-speed optical communications. In this paper, Modulation Instability (MI) as an approach in order to improve the performance of EO modulators, is investigated in the anomalous and zero-dispersion regimes of proposed optical fiber. In present conventional optical fibers, MI is observed over a few hundred gigahertz bandwidths at low pump power. In order to obtain ultra-wideband (a few Terahertz) bandwidths and maximum gain in the MI process at low pump power, a new structure for optical fiber is proposed. The genetic algorithm is utilized for performance optimization in optical fiber design. It is shown that the proposed optical fiber is able to support MI for a few Terahertz bands at low pump power (100 mW). Furthermore, in this analysis, it is demonstrated that higher-order dispersion terms have a strong impact on modulation instability. Finally, it is concluded that the geometrical and optical parameters of optical fiber are key factors to control modulation instability parameters (gain and bandwidth). The proposed optical fiber can be used as an optical booster in order to compensate frequency response of EO modulators, which is a considerable step forward in high-speed optical communication.

A Study of Financial Performance of Small-Scale Industries in Kashmir

Small scale industries are very important for economic growth and promotion of equitable development. They make up a large part of Kashmir’s economy. These units manufacture food products, beverages, machinery, plastic goods, chemicals, drugs, paper products, silk, brick and tiles, cement and automobile equipment’s. Small scale industries help in generating employment opportunities and labor intensity is much higher than that of the large enterprises. From the last two decades small scale industries sector have been growing in a satisfactory pace after a long gap of disturbance. Small scale industries are important for the wellbeing of the people of every country and helps in growth both economically and socially. It also contributes to the Gross State Domestic Product, that is, it contributes about 12. 55 % to the gross domestic product of the economy. The focus of this paper is to study the impact of financial performance of small – scale industries in Kashmir. Keywords: Small Scale Industries: Financial Performance: Growth: Employment: Economy: Labor Intensity: Kashmir.

The Challenges of Sustainable Development in Employee Retention of Large-Scale Industries in West Bengal Through Decent Work Indicators

Purpose – The notion of sustainable growth was introduced at the United Nations Conference on Sustainable Development in Rio de Janeiro in 2012. It was decided that developed countries' actions must support all the aims. The MDGs primarily addressed issues in underdeveloped and poor countries, whereas the SDGs also involve rich countries. MDGs assumed a ‘one-size-fits-all’ approach. The two most important factors of survival — the environment and development – are not adequately integrated. On the 25th of September 2015, the United Nations Sustainable Development Summit accepted the global agenda ‘Transforming Our World: the 2030 Agenda for Sustainable Development’. The purpose of the paper is to identify the proper retention strategy required for large scale industries in West Bengal in transition of change and to find the possibility of finding the scope of application of decent work indicators in large scale industries in West Bengal. Methodology - A total sample size of 607 participants from 22 large scale organizations in West Bengal is taken. Questions on decent work indicators are laid out on a five —point Likert scale. [5- Strongly Agree; 4-Agree; 3-Neither Agree nor Disagree; 2- Disagree: 1-Stronly Disagree]. The Secondary data had been collected from published and unpublished research works, research journals &amp; reference books, magazines &amp; Periodicals Newspapers, and websites, etc. This approach can be termed as doctrinal method of study. Results - The primary data reveal that decent work indicators can be used as important criteria for employee retention. This new approach has not been touched by earlier researchers. The objective of decent work is to improve the organization's capacity to handle its internal and external functioning and relationships. All discriminatory practices, unacceptable work conditions and violence including gender-based violence should be abolished. This helps in generating employee trust, belongingness towards organization. These practices are helpful for employee retention in large scale industries. This is growth of informal employment in regular wage category in organized and large-scale industries in West Bengal which is called as ‘formal informalization’. Practical application – Labor market uncertainties grew at a rapid pace in developing countries like India. Formal sector jobs had not been created at satisfactory pace and labor force migration took place towards informal sector. The new challenges have evolved due to rapid globalization in India. Frictional unemployment grew at a great pace in large scale industries in West Bengal. Development of proper decent work system under sustainable development agenda can create protection in the event of changes in economy and society, can reduce fear of change and can improve gainful and productive full employment in an economy.

ТЕОРЕТИЧНІ ТА МЕТОДИЧНІ ПІДХОДИ ДО ОЦІНЮВАННЯ ІНВЕСТИЦІЙНОЇ БЕЗПЕКИ УКРАЇНИ

The article discusses theoretical approaches to revealing the essence of the definition of «investment security». Investment security considered as a state of investment support of the country's economy, its resource capacity for expanded reproduction and modernization, attractiveness for investment in real and potential risks, threats and dangers. Investment security is a component of financial security, which in turn is an important component of the country's economic security. The main task of investment security is the formation of investment resources for the development of the country's economy, taking into account risks and threats. To assess the country's investment security, it is advisable to apply a comprehensive approach that would take into account its various aspects. Methodological tools have been developed and the level of investment security of Ukraine has been assessed and based on indicators that reflect: 1) ability to reproduce; 2) economic growth; 3) sources of investment. The quantitative value of these indicators allowed calculating the integrated indicator of investment security of Ukraine and noting that its level can be low, medium and high. On the authors position the low level of investment security signals the low investment attractiveness of the country's economy, significant imbalances in investment sources and lack of investment for expanded reproduction of fixed assets on an innovative basis. The average level of investment security reflects the satisfactory pace of investment in the country's economy and low use of the potential of financial intermediaries in investment activities. A high level of investment security, which guarantees expanded reproduction, economic growth and attracting the potential of the financial system in the investment process. The value of the integrated indicator of investment security of Ukraine for 2015-2019 is calculated. Testified to significant threats to economic growth and low rates of investment in the economy. The proposed methodology is comprehensive and allows assessing the level of investment security at the macro level.

Crossing the chasm: how to develop weather and climate models for next generation computers?

Abstract. Weather and climate models are complex pieces of software which include many individual components, each of which is evolving under pressure to exploit advances in computing to enhance some combination of a range of possible improvements (higher spatio-temporal resolution, increased fidelity in terms of resolved processes, more quantification of uncertainty, etc.). However, after many years of a relatively stable computing environment with little choice in processing architecture or programming paradigm (basically X86 processors using MPI for parallelism), the existing menu of processor choices includes significant diversity, and more is on the horizon. This computational diversity, coupled with ever increasing software complexity, leads to the very real possibility that weather and climate modelling will arrive at a chasm which will separate scientific aspiration from our ability to develop and/or rapidly adapt codes to the available hardware. In this paper we review the hardware and software trends which are leading us towards this chasm, before describing current progress in addressing some of the tools which we may be able to use to bridge the chasm. This brief introduction to current tools and plans is followed by a discussion outlining the scientific requirements for quality model codes which have satisfactory performance and portability, while simultaneously supporting productive scientific evolution. We assert that the existing method of incremental model improvements employing small steps which adjust to the changing hardware environment is likely to be inadequate for crossing the chasm between aspiration and hardware at a satisfactory pace, in part because institutions cannot have all the relevant expertise in house. Instead, we outline a methodology based on large community efforts in engineering and standardisation, which will depend on identifying a taxonomy of key activities – perhaps based on existing efforts to develop domain-specific languages, identify common patterns in weather and climate codes, and develop community approaches to commonly needed tools and libraries – and then collaboratively building up those key components. Such a collaborative approach will depend on institutions, projects, and individuals adopting new interdependencies and ways of working.

Fiscal Stress Analysis in the Republic of Serbia

Abstract The goal is to examine the level of fiscal stress in the Republic of Serbia and to investigate whetherit suggests a crisis of public debt. The empirical analysis of annual data has been done for the period 2007 to 2014, in two cases: (i) charging indicators of the vulnerability boundaries to the fiscal crisis using the signal approach (ii) an assessment of whether the public debt is reduced at a satisfactory pace by applying the criterion of the operationalisation of debt. The resulting composite indicator points to a crisis of public debt in the Republic of Serbia. The investigation of fiscal and macrofinancial variables showed that the public sector and private sector (macro-financial side) have over-consumption followed the process of the accumulation of the public debt. The outputs suggest that the level of the public debt in 2016 is above the benchmarks, which means that there is a violation of the operationalisation of the debt criterion in 2014.

Implications of the New Public Debt Rule in the ‘Fiscal Compact’ for the Economic and Monetary Union

This paper proposes a simple modeling of the dynamic evolution of the interest rate, budgetary deficit and public debt of a member country of a monetary union, if a representative investor has the choice between bonds from this country a benchmark bond. In this framework, we can analyze the consequences of the most recent measure included in the ‘Fiscal Compact'. After the financial Crisis, the coordination of public finances still mainly relies in Europe on rules of fiscal discipline. However, beyond the threshold on the budgetary deficit, a new stress is put on the reduction of the public debt at a ‘satisfactory pace': its distance with respect to the reference value must decrease at a rate of the order of one-twentieth per year. Then, we show that such a measure is fully reachable for Luxembourg, Finland, Germany, Austria or the Netherlands. However, the public debt target of 60% of GDP would necessitate sizeable fiscal consolidation efforts for Ireland, France and Belgium. Moreover, such a target would not even be stable for Italy, Portugal or Spain; and the Greek situation is explosive. Therefore, the new European fiscal framework appears as quite ambitious for some member countries of the Economic and Monetary Union.

Cardiac Resynchronization Therapy Delivered Via a Multipolar Left Ventricular Lead is Associated with Reduced Mortality and Elimination of Phrenic Nerve Stimulation: Long-Term Follow-Up from a Multicenter Registry.

Lower Mortality and Eliminated PNS Associated with Quadripolar LeadsIntroductionCardiac resynchronization therapy (CRT) using quadripolar left ventricular (LV) leads provides more pacing vectors compared to bipolar leads. This may avoid phrenic nerve stimulation (PNS) and allow optimal lead placement to maximize biventricular pacing. However, a long‐term improvement in patient outcome has yet to be demonstrated.MethodsA total of 721 consecutive patients with conventional CRTD criteria implanted with quadripolar (n = 357) or bipolar (n = 364) LV leads were enrolled into a registry at 3 UK centers. Lead performance and mortality was analyzed over a 5‐year period.ResultsPatients receiving a quadripolar lead were of similar age and sex to those receiving a bipolar lead, although a lower proportion had ischemic heart disease (62.6% vs. 54.1%, P = 0.02). Both groups had similar rates of procedural success, although lead threshold, impedance, and procedural radiation dose were significantly lower in those receiving a quadripolar lead. PNS was more common in those with quadripolar leads (16.0% vs. 11.6%, P = 0.08), but was eliminated by switching pacing vector in all cases compared with 60% in the bipolar group (P < 0.001). Furthermore, LV lead displacement (1.7% vs. 4.6%, P = 0.03) and repositioning (2.0% vs. 5.2%, P = 0.03) occurred significantly less often in those with a quadripolar lead. All‐cause mortality was also significantly lower in the quadripolar compared to bipolar lead group in univariate and multivariate analysis (13.2% vs. 22.5%, P < 0.001).ConclusionsIn a large, multicenter experience, the use of quadripolar LV leads for CRT was associated with elimination of PNS and lower overall mortality. This has important implications for LV pacing lead choice.

The Promise of Leadless Pacing: Based on Presentations at Nanostim Sponsored Symposium Held at the European Society of Cardiology Congress 2013, Amsterdam, The Netherlands, 2 September 2013.

Pacemaker technologies have advanced dramatically over the decades since they were first introduced, and every year many thousands of new implants are performed worldwide. However, there continues to be a high incidence of acute and chronic complications, most of which are linked to the lead or the surgical pocket created to hold the device. A leadless pacemaker offers the possibility of bypassing these complications, but requires a catheter-based delivery system and a means of retrieval at the end of the device's life, as well as a way of repositioning to achieve satisfactory pacing thresholds and R waves, a communication system and low peak energy requirements. A completely self-contained leadless pacemaker has recently been developed, and its key characteristics are discussed, along with the results of an efficacy and safety trial in an animal model. The results of the LEADLESS study, the first human trial to look at safety and feasibility of the leadless device, are discussed and the possible implications for future clinical practice examined.

Pacing alternans during broad complex tachycardia

Case summary A 56-year-old man with a history of myocardial infarction, left bundle branch block, and severe left ventricular systolic dysfunction (ejection fraction of 30%) underwent implantation of a biventricular implantable cardioverter-defibrillator (Medtronic Protecta D364TRG, Minneapolis, MN). The patient was referred to our institution for the implantation of a left ventricular lead following an unsuccessful attempt. Device check revealed a P wave of 2.4 mV, R wave of 11 mV, and satisfactory pacing thresholds and lead impedance. Shortly after presentation, the patient complained of palpitations and breathlessness. Electrocardiogram showed a regular broad complex tachycardia at a cycle length of 480 ms with intermittent pacing spikes (Figure 1). The programmed parameters were as follows: Pacing mode: DDD; Lower rate: 80 beats/min; Upper track rate: 130 beats/min; Paced/sensed atrioventricular (AV) delay: 350 ms; Mode switch: 171 beats/min; Ventricular safety pacing (VSP): ON; Noncompetitive atrial pacing: ON; Ventricular fibrillation detection: 188 beats/min; Ventricular tachycardia detection: 150 beats/min (monitor); What is the cause of the intermittent pacing stimuli?

Video-Assisted Thoracoscopic Left Ventricular Pacing in Patients With and Without Previous Sternotomy

Left ventricular epicardial lead placement via video-assisted thoracoscopy (VAT) is a recognized surgical technique to achieve cardiac resynchronization therapy (CRT) when conventional lead placement has failed. Its role in patients with previous sternotomy is uncertain. We describe our experience in a cohort of patients including those with previous sternotomy. This was a retrospective review of consecutive patients undergoing VAT lead implantation for CRT in a single center between 2004 and 2011. All patients fulfilled conventional criteria for CRT and were followed up at 4 to 6 weeks and then at 3-month intervals. Clinical and pacing parameters were compared at baseline and at the latest review. Thirty-two patients (27 men; mean age, 67 ± 9 years) underwent VAT left ventricular lead implantation. Mean follow-up duration was 704 ± 450 days. Ten patients (31%) had undergone previous sternotomy. Thoracoscopic lead implantation was successful in 31 patients (97%): 1 patient with two previous sternotomies required conversion to open thoracotomy due to bleeding with multiple adhesions. Satisfactory implantation pacing thresholds of 2 volts or less at 0.5 ms were achieved in all patients. Despite a longer operative time in those with previous sternotomy, all clinical and pacing outcomes, including complications, clinical response to CRT, and long-term pacing variables were similar between the groups. VAT left ventricular lead placement appears safe and effective in selected patients with previous sternotomy, including coronary artery bypass operations, with postoperative outcomes comparable with those patients without previous sternotomy.

Residential photovoltaic systems in Greece and in other European countries: a comparison and an overview

One of the most promising renewable energy technologies (renewable energy sources, RESs) is photovoltaics (PVs). PVs are a truly elegant means of producing electricity on site, directly from the sun, without concern for energy supply or environmental harm. They represent a favorable case: easy and fast installation, low maintenance requirements and the ability to produce electricity on site within the urban built environment. In that sense, there is a growing consensus that PVs for individual buildings, known as building integrated or applied PVs (BIPVs or BAPVs, respectively), will be chief among the continuously widespread distributed PV applications. Still, they suffer from the disadvantage of their very high initial cost compared to other renewable and conventional energy technologies, although this has been steadily reduced during the last 5 years. It is therefore evident that without the support of suitable instruments, the expansion of solar electricity worldwide would not take place at a satisfactory pace. Various effective support mechanisms have been adopted, within which feed-in tariff (FiT) proved to be the most successful for PVs. That is the case also in Greece, where the PV market in the building sector grew rapidly after 2009, due to the great FiT incentives granted particularly for residential applications. In this paper an overview is provided, accompanied by a comparative feasibility study regarding residential PV systems’ prospects, based on the review of all kinds of incentive schemes in EU for small-scale BAPVs.

152 Real-time cardiac MR anatomy and dyssynchrony overlay to guide left ventricular lead placement in CRT

<h3>Introduction</h3> Optimal left ventricular (LV) lead placement via the coronary sinus (CS) is a critical factor in defining response to cardiac resynchronisation therapy (CRT). Using novel semi-automated image acquisition, segmentation, overlay and registration software we set out to guide lead placement by avoiding scar and targeting the region of the LV with the latest mechanical activation. <h3>Methods</h3> 17 patients underwent cardiac magnetic resonance (CMR) scans. 3D whole heart images were segmented to produce high fidelity anatomical models of the cardiac chambers and coronary veins. 2, 3, 4 chamber and short axis cine images were processed using Tomtec software to give a 16 segment time volume-dyssynchrony map. In patients with myocardial scar the late gadolinium enhancement images were manually segmented and registered to the anatomical model along with the dyssynchrony map. The 3 latest mechanically activated segments with &lt;50% scar were identified and this information was overlaid at CRT implant on to live fluoroscopic images using a prototype version of the Philips EP Navigator software. Subsequently, the x-ray C-arm and table could be moved freely while automatically maintaining a registered roadmap. We used a high fidelity pressure wire to assess the acute haemodynamic response to pacing in different regions of the overlaid 16 segment model. All dP/dt measurements were compared to baseline AAI or VVI (for those patients in AF) pacing at 5–10 beats/min above intrinsic rate. <h3>Results</h3> 15 of the 17 patients underwent successful placement of a LV pacing lead via the CS with satisfactory pacing parameters and no phrenic nerve stimulation at implant. The mean time from insertion of the CS guide catheter into the venous sheath to successful cannulation of the CS was 1.3±1.0 min. In 2 patients we were unable to place a LV lead successfully in any branch of the CS. We paced in at least one of our 3 target segments in 11 patients. 67% of patients were responders as defined by a 10% increase in +dP/dt over baseline. The mean change in +dP/dt for the best lead position vs baseline+dP/dt was 15.9±11.3% for DDDLV pacing. This compares to a mean change in+dP/dt of 14.9±12.3% when the CMR dyssynchrony-map defined target region was paced DDDLV. The region of best+dP/dt response was postero-lateral, lateral or posterior in all cases. <h3>Conclusion</h3> We have shown it is feasible to acquire, overlay and accurately register cardiac MR data on to fluoroscopic images at the time of CRT implant. Our data suggest that it is also possible to identify and place the LV lead in at least one target region in most patients. This appears to give close to the best acute haemodynamic response that can be achieved in any branch of the CS. The initial results of this pilot study suggest that a MR dyssynchrony guided approach to LV lead placement may allow ideal LV lead positioning (Abstract 152 figures 1 and 2).

The Promise of Leadless Pacing: Based on Presentations at Nanostim Sponsored Symposium Held at the European Society of Cardiology Congress 2013, Amsterdam, The Netherlands, 2 September 2013

Pacemaker technologies have advanced dramatically over the decades since they were first introduced, and every year many thousands of new implants are performed worldwide. However, there continues to be a high incidence of acute and chronic complications, most of which are linked to the lead or the surgical pocket created to hold the device. A leadless pacemaker offers the possibility of bypassing these complications, but requires a catheter-based delivery system and a means of retrieval at the end of the device’s life, as well as a way of repositioning to achieve satisfactory pacing thresholds and R waves, a communication system and low peak energy requirements. A completely self-contained leadless pacemaker has recently been developed, and its key characteristics are discussed, along with the results of an efficacy and safety trial in an animal model. The results of the LEADLESS study, the first human trial to look at safety and feasibility of the leadless device, are discussed and the possible implications for future clinical practice examined.