Effect of Contact Force on Pulsed Field Ablation Lesions in Porcine Cardiac Tissue.

BACKGROUND Contact force has been used to titrate lesion formation for radiofrequency ablation. Pulsed Field Ablation (PFA) is a field-based ablation technology for which limited evidence on the impact of contact force on lesion size is available. METHODS Porcine hearts (n=6) were perfused using a modified Langendorff set-up. A prototype focal PFA catheter attached to a force gauge was held perpendicular to the epicardium and lowered until contact was made. Contact force was recorded during each PFA delivery. Matured lesions were cross-sectioned, stained, and the lesion dimensions measured. RESULTS A total of 82 lesions were evaluated with contact forces between 1.3 g and 48.6 g. Mean lesion depth was 4.8 ± 0.9 mm (standard deviation), mean lesion width was 9.1 ± 1.3 mm and mean lesion volume was 217.0. ± 96.6 mm3 . Linear regression curves showed an increase of only 0.01 mm in depth (Depth = 0.01*Contact Force + 4.41, R2 = 0.05), 0.03 mm in width (Width = 0.03*Contact Force + 8.26, R2 = 0.13) for each additional gram of contact force, and 2.20 mm3 in volume (Volume = 2.20*Contact Force + 162, R2 = 0.10). CONCLUSIONS Increasing contact force using a bipolar, biphasic focal PFA system has minimal effects on acute lesion dimensions in an isolated porcine heart model and achieving tissue contact is more important than the force with which that contact is made. This article is protected by copyright. All rights reserved

Investigation of the Photocatalytic Hydrogen Production of Semiconductor Nanocrystal-Based Hydrogels

Destabilization of a ligand-stabilized semiconductor nanocrystal solution with an oxidizing agent can lead to a macroscopic highly porous self-supporting nanocrystal network entitled hydrogel, with good accessibility to the surface. The previously reported charge carrier delocalization beyond a single nanocrystal building block in such gels can extend the charge carrier mobility and make a photocatalytic reaction more probable. The synthesis of ligand-stabilized nanocrystals with specific physicochemical properties is possible, thanks to the advances in colloid chemistry made in the last decades. Combining the properties of these nanocrystals with the advantages of nanocrystal-based hydrogels will lead to novel materials with optimized photocatalytic properties. This work demonstrates that CdSe quantum dots, CdS nanorods, and CdSe/CdS dot-in-rod-shaped nanorods as nanocrystal-based hydrogels can exhibit a much higher hydrogen production rate compared to their ligand-stabilized nanocrystal solutions. The gel synthesis through controlled destabilization by ligand oxidation preserves the high surface-to-volume ratio, ensures the accessible surface area even in hole-trapping solutions and facilitates photocatalytic hydrogen production without a co-catalyst. Especially with such self-supporting networks of nanocrystals, the problem of colloidal (in)stability in photocatalysis is circumvented. X-ray photoelectron spectroscopy and photoelectrochemical measurements reveal the advantageous properties of the 3D networks for application in photocatalytic hydrogen production

Randomized, double blind study of non-excitatory, cardiac contractility modulation electrical impulses fr symptomatic heart failure

AIMS: We performed a randomized, double blind, crossover study of cardiac contractility modulation (CCM) signals in heart failure patients. METHODS AND RESULTS: One hundred and sixty-four subjects with ejection fraction (EF) < 35% and NYHA Class II (24%) or III (76%) symptoms received a CCM pulse generator. Patients were randomly assigned to Group 1 (n = 80, CCM treatment 3 months, sham treatment second 3 months) or Group 2 (n = 84, sham treatment 3 months, CCM treatment second 3 months). The co-primary endpoints were changes in peak oxygen consumption (VO2,peak) and Minnesota Living with Heart Failure Questionnaire (MLWHFQ). Baseline EF (29.3 +/- 6.7% vs. 29.8 +/- 7.8%), VO2,peak (14.1 +/- 3.0 vs. 13.6 +/- 2.7 mL/kg/min), and MLWHFQ (38.9 +/- 27.4 vs. 36.5 +/- 27.1) were similar between the groups. VO2,peak increased similarly in both groups during the first 3 months (0.40 +/- 3.0 vs. 0.37 +/- 3.3 mL/kg/min, placebo effect). During the next 3 months, VO2,peak decreased in the group switched to sham (-0.86 +/- 3.06 mL/kg/min) and increased in patients switched to active treatment (0.16 +/- 2.50 mL/kg/min). MLWHFQ trended better with treatment (-12.06 +/- 15.33 vs. -9.70 +/- 16.71) during the first 3 months, increased during the second 3 months in the group switched to sham (+4.70 +/- 16.57), and decreased further in patients switched to active treatment (-0.70 +/- 15.13). A comparison of values at the end of active treatment periods vs. end of sham treatment periods indicates statistically significantly improved VO2,peak and MLWHFQ (P = 0.03 for each parameter). CONCLUSION: In patients with heart failure and left ventricular dysfunction, CCM signals appear safe; exercise tolerance and quality of life (MLWHFQ) were significantly better while patients were receiving active treatment with CCM for a 3-month period

Cardiovascular care of patients with stroke and high risk of stroke: The need for interdisciplinary action: A consensus report from the European Society of Cardiology Cardiovascular Round Table.

Comprehensive stroke care is an interdisciplinary challenge. Close collaboration of cardiologists and stroke physicians is critical to ensure optimum utilisation of short- and long-term care and preventive measures in patients with stroke. Risk factor management is an important strategy that requires cardiologic involvement for primary and secondary stroke prevention. Treatment of stroke generally is led by stroke physicians, yet cardiologists need to be integrated care providers in stroke units to address all cardiovascular aspects of acute stroke care, including arrhythmia management, blood pressure control, elevated levels of cardiac troponins, valvular disease/endocarditis, and the general management of cardiovascular comorbidities. Despite substantial progress in stroke research and clinical care has been achieved, relevant gaps in clinical evidence remain and cause uncertainties in best practice for treatment and prevention of stroke. The Cardiovascular Round Table of the European Society of Cardiology together with the European Society of Cardiology Council on Stroke in cooperation with the European Stroke Organisation and partners from related scientific societies, regulatory authorities and industry conveyed a two-day workshop to discuss current and emerging concepts and apparent gaps in stroke care, including risk factor management, acute diagnostics, treatments and complications, and operational/logistic issues for health care systems and integrated networks. Joint initiatives of cardiologists and stroke physicians are needed in research and clinical care to target unresolved interdisciplinary problems and to promote the best possible outcomes for patients with stroke

World Heart Federation Roadmap on Atrial Fibrillation - A 2020 Update

The World Heart Federation (WHF) commenced a Roadmap initiative in 2015 to reduce the global burden of cardiovascular disease and resultant burgeoning of healthcare costs. Roadmaps provide a blueprint for implementation of priority solutions for the principal cardiovascular diseases leading to death and disability. Atrial fibrillation (AF) is one of these conditions and is an increasing problem due to ageing of the world’s population and an increase in cardiovascular risk factors that predispose to AF. The goal of the AF roadmap was to provide guidance on priority interventions that are feasible in multiple countries, and to identify roadblocks and potential strategies to overcome them. Since publication of the AF Roadmap in 2017, there have been many technological advances including devices and artificial intelligence for identification and prediction of unknown AF, better methods to achieve rhythm control, and widespread uptake of smartphones and apps that could facilitate new approaches to healthcare delivery and increasing community AF awareness. In addition, the World Health Organisation added the non-vitamin K antagonist oral anticoagulants (NOACs) to the Essential Medicines List, making it possible to increase advocacy for their widespread adoption as therapy to prevent stroke. These advances motivated the WHF to commission a 2020 AF Roadmap update. Three years after the original Roadmap publication, the identified barriers and solutions were judged still relevant, and progress has been slow. This 2020 Roadmap update reviews the significant changes since 2017 and identifies priority areas for achieving the goals of reducing death and disability related to AF, particularly targeted at low-middle income countries. These include advocacy to increase appreciation of the scope of the problem; plugging gaps in guideline management and prevention through physician education, increasing patient health literacy, and novel ways to increase access to integrated healthcare including mHealth and digital transformations; and greater emphasis on achieving practical solutions to national and regional entrenched barriers. Despite the advances reviewed in this update, the task will not be easy, but the health rewards of implementing solutions that are both innovative and practical will be great

Stroke risk associated with balloon based catheter ablation for atrial fibrillation: Rationale and design of the MACPAF Study

<p>Abstract</p> <p>Background</p> <p>Catheter ablation of the pulmonary veins has become accepted as a standard therapeutic approach for symptomatic paroxysmal atrial fibrillation (AF). However, there is some evidence for an ablation associated (silent) stroke risk, lowering the hope to limit the stroke risk by restoration of rhythm over rate control in AF. The purpose of the prospective randomized single-center study "Mesh Ablator versus Cryoballoon Pulmonary Vein Ablation of Symptomatic Paroxysmal Atrial Fibrillation" (MACPAF) is to compare the efficacy and safety of two balloon based pulmonary vein ablation systems in patients with symptomatic paroxysmal AF.</p> <p>Methods/Design</p> <p>Patients are randomized 1:1 for the Arctic Front^®or the HD Mesh Ablator^®catheter for left atrial catheter ablation (LACA). The predefined endpoints will be assessed by brain magnetic resonance imaging (MRI), neuro(psycho)logical tests and a subcutaneously implanted reveal recorder for AF detection. According to statistics 108 patients will be enrolled.</p> <p>Discussion</p> <p>Findings from the MACPAF trial will help to balance the benefits and risks of LACA for symptomatic paroxysmal AF. Using serial brain MRIs might help to identify patients at risk for LACA-associated cerebral thromboembolism. Potential limitations of the study are the single-center design, the existence of a variety of LACA-catheters, the missing placebo-group and the impossibility to assess the primary endpoint in a blinded fashion.</p> <p>Trial registration</p> <p>clinicaltrials.gov NCT01061931</p

The patient pathway in cardiovascular care: a position paper from the International Pharmacists for Anticoagulation Care Taskforce (iPACT)

"Background: This position paper highlights the opportunistic integral role of the pharmacist across the patient pathway utilizing cardiovascular care as an example. The paper aims to highlight the potential roles that pharmacists worldwide can have (or already have) to provide efficient patient care in the context of interprofessional collaboration. Methods: It results from a literature review and experts seeking advice to identify existing interventions and potential innovative interventions. We developed a conceptual framework highlighting seven critical phases in the patient pathway and for each of those listed some of the initiatives identified by our experts worldwide. Results: Existing pharmacists' interventions in each of these phases have been identified globally. Various examples in the area of prevention and self‐management were found to exist for long; the contribution for early detection and subsequently to timely diagnosis were also quite clear; integration of care was perhaps one of the areas needing greater development, although interventions in secondary care were also quite common. Tertiary care and end of life interventions were found to often be left for other healthcare professionals. Conclusion: On the basis of the findings, we can argue that much has been done but globally consider that pharmacists are still an untapped resource potentially useful for improved patient care."info:eu-repo/semantics/publishedVersio