Emission characteristics of bulk aerosols excited by externally focused femtosecond filaments

The bulk aerosol emissions excited by externally focused femtosecond laser filaments are characterized using time-resolved plasma imaging and spectroscopy. Images of N₂ and N2+ plasma fluorescence are used to characterize the filament dimensions. Emission profiles from bulk Sr aerosols are studied, showing that several localized emission regions in the filament begin to develop for lower repetition rates and higher pulse energies. Plasma temperature and electron density profiles are determined using particle emissions along the length of short- and long-focused filaments, and results are compared for on-axis and side-collected spectra. The use of on-axis collection enables the sampling of light emitted over the entire length of the filament; however, the necessary back-propagation of light makes on-axis collection susceptible to self-absorption as the optical path is extended through the filament plasma column formed in bulk aerosols.

Detecting and characterizing special nuclear material for nuclear nonproliferation applications

There is an urgent need for new, better instrumentation and techniques for detecting and characterizing special nuclear material (SNM), i.e., highly enriched uranium and plutonium. The development of improved instruments and techniques requires experiments performed with the SNM itself, which is of limited availability. This paper describes the findings of experiments performed at the National Criticality Experiments Research Center conducted using new instruments and techniques on unclassified, kg-quantity SNM objects. These experiments, performed in the framework of the Department of Energy, National Nuclear Security Administration Consortium for Monitoring, Technology, and Verification, focused on detecting, characterizing, and localizing SNM samples with masses ranging from 3.3 to 13.8 kg, including plutonium and highly enriched uranium using prototype detectors and techniques. The work demonstrates SNM detection and characterization using recently-developed prototype detection systems. Specifically, we present new results in passive detection and imaging of plutonium and uranium objects using gamma-ray and dual particle (fast neutron and gamma-ray) imaging. We also present a new analysis of the delayed neutron emissions during active interrogation of uranium using a neutron generator.

Generation of multiple obstruction-free channels for free space optical communication

Multi-filament structures produced by vortical high-power femtosecond pulses propagating through clouds and fog can simultaneously clear two channels with cylindrical and annular profile. We present a method to achieve Free Space Optical (FSO) communications through such highly scattering media by propagating appropriately shaped laser modes through these channels. As a proof of concept, we implemented a Laguerre-Gaussian beam as information signal carrier to demonstrate transmission of 543-nm CW laser beam through a 1-m long cloud chamber using both channels. The low power of the information signal in this experiment allows considering applications in Earth-satellite FSO communication.

Additive negative prognostic value of coronary flow reserve in patients with left bundle branch block without inducible ischemia and without known coronary artery disease

Background

Left bundle branch block (LBBB) can be isolated thing, but it is also often associated with underlying coronary artery disease (CAD). Stress echocardiography (SECHO) is widely used as an imaging method for the diagnosis of CAD. However, the diagnostic value of stress echocardiography in patients (pts) with LBBB is limited.

Purpose

To evaluate negative prognostic value of coronary flow reserve (CFR) in pts with LBBB without inducible ischemia and without known CAD.

Methods

This retrospective study included 224 pts (98, 43.8% male gender, average age 66±11 years) with LBBB and without known CAD. All the pts had negative SECHO test according the Bruce protocol. Risk factors for CAD (diabetes, smoking, hypertension, high cholesterol and positive family history of CAD), Duke treadmill score, functional capacity (Metabolic Equivalents - METs) were recorded in all pts. Out of 224 pts, in 64 (29.5%) coronary flow reserve on the left anterior descending artery was assessed using pulsed Doppler echocardiography with adenosine in a dose of 140μcg/kg/body weight during 3 minutes. As the normal value we took value of CFR ≥2. Median follow up of the pts was 72 months (IQR 56.25–132 months) for the occurrence of MACE (cardiovascular death (CVD), non-fatal myocardial infarction (nfMI), coronary artery bypass graft (CABG) and percutaneous coronary revascularization (PCI).

Results

Out of 224 pts, 6 (2.7%) had positive SECHO test, 2 pts (0.9%) had died due to non-cardiac causes and 11 pts (4.9%) were lost to follow up so they were excluded from further analysis. The remaining 204 pts were divided in 2 groups: 1. pts with only negative SECHO (n=144, 68.8%); 2. pts with negative SECHO and normal CFR (n=64, 31.2%). During the follow-up period 22 out of 205 pts (10.7%) had an adverse event (6 CVD, 6 nfMI, 5 CABG, 8 PCI). Between the two groups there was no significant difference in risk factors and parameters of the SECHO test. Pts with CFR had significantly lower rate of MACE compared to the pts with only SECHO test (2, 3.1% vs 20, 14.2%, p=0.018, respectively). Using the Cox regression analysis, univariate predictors of MACE were insulin dependent diabetes (HR 10.851 [95% CI 2.095–56.220], p=0.004), Duke score (HR 0.603 [95% CI 0.414–0.878], p=0.008), and MET (HR 0.393 [95% CI 0.209–0.737], p=0.004). In the multivariate analysis only the insulin dependent diabetes remained an independent predictor of MACE (HR 6.906 [95% CI 1.100–43.363], p=0.039). Using the Kaplan-Meier survival curve we see that the pts with SECHO test and CFR had shorter event-free time compared to the pts with SECHO test (136.3±3.6 months vs 149.8±2.9 months, Log Rank 4.022, p=0.045) (Figure 1).

Conclusion

Normal value of CFR has good negative prognostic value in pts with LBBB without inducible ischemia and without known CAD, while pts with insulin dependent diabetes have more pronounced risk for the occurrence of adverse events.

Funding Acknowledgement

Type of funding sources: None.

Haemodynamic indicators of arteriolar dysregulation during combined hyperventilation and exercise test in patients with ANOCA (SESPASM)

Introduction

In patients with angina and non-obstructed coronary arteries (ANOCA), functional dysregulation such as epicardial coronary spasm and microvascular dysfunction (microvascular spasm and /or impaired microvascular dilatation) frequently coexist.

The aim was to analyse haemodynamic indicators of arteriolar dysregulation during combined hyperventilation and exercise stress echo test in patients with ANOCA.

Methods

In a prospective study we enrolled 38 patients (56±13 years, 31 females) with ANOCA, proven by normal coronary angiogram. Stress echocardiography protocol with Doppler measurements of coronary flow consisted of hyperventilation test for spasm provocation (HYP, respiratory rate of 30 per min for 5') followed by supine bicycle exercise test (HYP+EXE) for assessment of endothelium dependent function. Adenosine test was done (ADO 140 mcg/kg in 1 min) for estimation of endothelium independent vasodilatation. Coronary flow velocity (CFV) was assessed in distal LAD by Transthoracic Doppler echocardiography at the end of the each stage of the test. Abnormal response to HYP was a CFV ratio (stress/rest) <1.0 (vasoconstrictor response). CFV ratio at peak HYP+ EXE was an indicator of endothelial dependent vasodilatation (<2 blunted response). An abnormal response to ADO was a CFV reserve <2.0 (blunted vasodilatory response).

Results

The double product increased during HYP in comparison to rest (13263 vs 10321, p<0.001), and further increased with EXE (23817 vs HYP, p<0.001). Chest pain was present in 6 pts during HYP, and in additional three pts during HYP+EXE (15.8% vs 23.7%, p=0.25). ST segment depression was present in 6 pts during HYP and 23 during HYP+EXE (15.79% vs 60.52%, p<0.001). Wall motion abnormality was provoked with HYP in three pts (7.89%) and in ten (26.3%) with HYP+EXE (p=0.016). CFV ratio was abnormal for vasoconstriction during HYP in 16 (42.1%) and blunted in 23 (60.52%) pts during HYP+EXE (Fig 1). Vasodilation during ADO was preserved in all patients, but one. There was significant difference between CFV reserve during HYP+EXE vs ADO (1.98±0.49 vs 2.53±0.43 respectively, p<0.001) (Fig. 2).

Conclusion

Our results indicate that HYP induce microvascular dysfunction with vasospastic component which is reflected in reduced CFV ratio. This prevents the normal hyperemic response during EXE in more than a half of patients. Endothelial independent vasodilatation during ADO hyperemia was perserved in all patients, excluding structural microvasculature remodeling. HYP+EXE provocation with noninvasive measurement of coronary flow is a promising test for assessing mechanism of arteriolar dysregulation in ANOCA patients.

Funding Acknowledgement

Type of funding sources: None.

Comparison of SCORE and SCORE 2 risk prediction tools in contemporary very high risk european population

Background

New SCORE 2 algorithm overperformed SCORE algorithm in population with decreasing prevalence of cardiovascular (CV) morbidity and mortality. However, there is limited data in risk stratification with SCORE 2 model in contemporary populations from very high risk countries.

Aim

The aim of this study was to compare risk prediction using SCORE 2 and SCORE model and to compare the proportions of patients requiring statin treatment in primary prevention.

Methods

Our study included 1317 patients (511, 38.8% male gender, average age 54±8) without known CV disease aged 40 to 70 years. Data on CV risk factors were prospectively collected in 20 primary care centers throughout the Serbia from January 2020. to December 2020. Based on the CV risk profile, patients were stratified into 4 categories: low, moderate, high and very high risk according to SCORE model and into 3 categories: low to moderate, high and very high risk according to SCORE 2 model. The number of patients requiring statin treatment was assessed according to the risk category and value of LDL cholesterol in SCORE model and the value of non-HDL cholesterol in SCORE 2 model.

Results

Overall, 589 patients (44.7%) were smokers, mean value of total cholesterol was 6.2±1.1 mmol/L, LDL 3.9±1.1, HDL 1.4±0.5, non HDL 4.8±1.2 mmol/L. Systolic blood pressure was 138.6±19.6, diastolic blood pressure was 85.3±10.4 mmHg and was BMI 26.9±5.2. Based on the SCORE model 166 patients (12.6%) were classified into low risk category, 658 (49.9%) into moderate, 276 (20.9%) into high risk and 217 (16.6%) into very high risk category. Based on the SCORE 2 model 30 (2.8%) patients were classified into low to moderate, 273 (18%) and 1014 (79.2%) into very high risk category. There was significantly less patients in low to moderate group in SCORE 2 model compared to SCORE model (30, 2.8% vs 824, 62.6%, p<0.001 respectively) and significantly more patients with very high risk (1014, 79.2% vs 217, 16.6%, p<0.001), but without significance difference in the high risk group (Figure 1). The use of SCORE 2 model resulted in significantly higher proportion of patients requiring statin treatment 93% vs. 43% using SCORE model (p<0.001).

Conclusion

The use SCORE 2 risk prediction tool, in comparison to SCORE model, results in significant higher proportion of patients being classified as very high risk category with the increase number of patients requiring statin treatment in primary prevention.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Krka Farma

Iterative wavefront optimization of ultrafast laser beams carrying orbital angular momentum

Structured intense laser beams offer degrees of freedom that are highly attractive for high-field science applications. However, the performance of high-power laser beams in these applications is often hindered by deviations from the desired spatiotemporal profile. This study reports the wavefront optimization of ultrafast Laguerre-Gaussian beams through the synergy of adaptive optics and genetic algorithm-guided feedback. The results indicate that the intensity fluctuations along the perimeter of the target ring-shaped profile can be reduced up to ∼15%. Furthermore, the radius of the ring beam profile can be tailored to a certain extent by establishing threshold fitting criteria. The versatility of this approach is experimentally demonstrated in conjunction with different focusing geometries.

Ultra-broadband long-wave-infrared pulse production using a chirped-pulse difference-frequency generation

We present a broadband light source based on near-infrared chirped-pulse difference-frequency mixing that is suitable for seeding long-wave-infrared (LWIR) optical parametric chirped-pulse amplification (OPCPA). A nitrocellulose pellicle is used in a Ti:sapphire regenerative amplifier to generate dual-frequency output pulses, which are subsequently mixed in a 0.4-mm thick AgGaS₂ crystal. LWIR pulses with ∼1 µm full width at half maximum (FWHM) bandwidth centered at 10.5 µm are generated by mixing transform-limited pulses. Assisted by genetic algorithm optimization, the bandwidth is broadened to ∼3 µm FWHM within the 8-12 µm atmospheric transmission window. The seed source paves the path towards tabletop ultrafast terawatt-class passively carrier-envelope-phase stabilized OPCPA in the LWIR region.

Assessment of left ventricular contractile reserve during hyperventilation and exercise in patients with ANOCA

Funding Acknowledgements

Type of funding sources: None.

Introduction. Mechanism of ischemia in patients with angina and no obstructive coronary artery disease (ANOCA), is often unrecognized since invasive tests are seldom done and proper noninvasive test is not established yet.

The aim of our study was to assess changes in ventricular function during hyperventilation test  (HYP) designed to provoke vasoconstriction, immediately followed by supine bicycle exercise to increase ischemic stimuli in patients with ANOCA (HYP + EXE).

Methods. : In a prospective study, we enrolled 29 ANOCA patients  (age 59.6 ±11 years, 27 females) with previously normal angiograms. All patients underwent SE testing with hyperventilation (HYP, respiratory rate of 30 per min for 5"), immediately followed by supine bicycle exercise (HYP + EXE). Ventricular function was assessed based on left ventricular contractile reserve (LVCR), calculated by ratio of the ventricular force at the peak of the each stress level and rest. Force was assessed as the quotient between systolic arterial pressure and end-systolic volume determined by two-dimensional echocardiography. Values range from normal (> 2.0) to mild (1.5–2.0), moderate (1.01–1.49), and severe (≤1.0) dysfunction. For LVCR HYP values are shifted towards lower values (abnormal < 1.1).

Results. Chest pain or dyspnea were present in 4/29 pts during HYP, and in 7/29 patients during HYP + EXE (13.8% vs 24.1 %, p = 0.001). Three patients showed wall motion abnormalities with hyperventilation and additional two patients with HYP + EXE. LVCR HYP response was normal in 19/29 (65.5%) pts and abnormal in 10/29 (34.5%) pts. LVCR HYP + EXE response was normal in 9/29 (31%) pts, 4/29 (13.8%) pts had mild, 11/29 (37.9%) pts had moderate and 5/29 (17.3%) pts had severe dysfunction.

Conclusion. In patients with ANOCA subtle changes in LV function occurred with HYP and EXE stress more often than wall motion abnormality. Measurement of contractile reserve might be a useful tool in assessment of ischemia and ventricular dysfunction in patients with ANOCA. Abstract Figure 1.  Abstract Figure 2.

Noninvasive functional testing in ANOCA: hyperventilation-exercise study for spasm (SESPASM)

Introduction

In patients with angina and no obstructive coronary artery disease (ANOCA), different mechanisms of ischaemia, epicardial spasm, microvascular spasm, and impaired microvascular dilatation frequently coexist.

The aim was to assess CFVR changes during coronary vasoconstrictor and vasodilator stimuli in patients with ANOCA.

Methods

In a prospective single center study, we enrolled 29 ANOCA patients (age 59.6±11 years, 27 females) with previously normal angiograms. All underwent SE testing with hyperventilation (HYP, respiratory rate of 30 per min for 5') followed by supine bicycle exercise (HYP+EXE); and adenosine CFV evaluation (ADO 140 mcg/kg in 1 min) on the other day. Coronary flow velocity (CFV) was assessed in distal LAD by Transthoracic Doppler echocardiography. The ratio of peak/rest changes of CFV during HYP in LAD was taken as an index of vasoconstriction, and CFV reserve was evaluated after EXE. An abnormal response to HYP was a CFV ratio <1.0 (vasoconstrictor response). An abnormal response to ADO was a CFV reserve <2.0 (blunted vasodilatory response). CFVR at peak HYP+ EXE was an indicator of endothelial dependent vasodilatation.

Results

The double product increased during HYP, in comparison to rest (13213 vs 10517, p<0.01), and further increased with EXE (23387 vs HYP, p<0.001). Chest pain or dyspnea were present in 4/29 pts during HYP, and in 7/29 patients during HYP+EXE (13.8% vs 24.1%, p=0.001). ST segment depression (≥1mm) was present in 7/29 patients during HYP, and 14/29 during HYP+EXE (24.13% vs 48.3%, p<0.01). Five patients (17%) showed regional wall motion abnormalities with HYP+EXE. CFVR response was abnormal in 19/29 (65%) patients during HYP+EXE, and abnormal for vasoconstriction during HYP in 13 (44%). Vasodilation during ADO was preserved in all patients.There was significant difference between CFVR response during HYP+EXE and ADO (1.9±0.35 vs 2.47±0.42 respectively, p<0.01), and between CFVR HYP and ADO (1.28±0.29 vs 2.47±0.42, p<0.001).

Conclusion

In patients with ANOCA, HYP+EXE is a more powerful ischemic stress than HYP alone. In over one-half of patients HYP+EXE unmasks abnormalities in CFVR response and/or regional wall motion, likely unmasking the underlying endothelium dependent microcirculatory dysfunction with enhanced vasoconstriction in 44% of the patients and mixed vasoconstriction and reduced relaxation in 65%.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): University Clinical Centre of Serbia, Faculty of Medicine

Single-shot, double-pulse determination of the detonation energy in nanosecond-laser ablation using the blast model

We demonstrate a novel single-shot method to determine the detonation energy of laser-induced plasma and investigate its performance. This approach can be used in cases where there are significant shot-to-shot variations in ablation conditions, such as laser fluctuations, target inhomogeneity, or multiple filamentation with ultrashort pulses. The Sedov blast model is used to fit two time-delayed shadowgrams measured with a double-pulse laser. We find that the reconstruction of detonation parameters is insensitive to the choice of interpulse delay in double-pulse shadowgraphy. In contrast, the initial assumption of expansion dimensionality has a large impact on the reconstructed detonation energy. The method allows for a reduction in the uncertainties of blast wave energy measurements as a diagnostic technique employed in various laser ablation applications.

Optimization of the electron beam dump for a GeV-class laser electron accelerator

The advances of laser-driven electron acceleration offer the promise of great reductions in the size of high-energy electron accelerator facilities. Accordingly, it is desirable to design compact radiation shielding for such facilities. A key component of radiation shielding is the high-energy electron beam dump. In an effort to optimize the electron beam dump design, different material combinations have been simulated with the FLUKA Monte Carlo code in the range of 1-40 GeV. The studied beam dump configurations consist of alternating layers of high-Z material (lead or iron) and low-Z material (high-density concrete or borated polyethylene) in either three-layer or five-layer structures. The designs of various beam dump configuration have been compared and it has been found that the iron and concrete stacking in a three-layer structure with a thick iron layer results in the lowest dose at 1, 10, and 40 GeV. The performance of the beam dump exhibits a strong dependence on the selected materials, the stacking method, the beam dump thickness, as well as the electron energy. This parametric study provides general insights that can be used for compact shielding design of future electron accelerator facilities.

Efficacy and safety of Cerebrolysin after futile recanalisation therapy in patients with severe stroke

INTRODUCTION

Golden standard of acute stroke treatment is recanalisation therapy. However, opening the occluded blood vessel sometimes does not show the expected clinical result or leads to haemorrhagic complications. As neuroinflammation and neurotoxicity play an important role in the pathophysiology of stroke, neuroprotective agents might preserve brain tissue after futile recanalisation.

PATIENTS AND METHODS

After recanalisation therapy and not later than 24 h after symptoms onset, patients with initial NIHSS of ≥ 8 were assigned to the investigational and control group. The investigational group received intravenous Cerebrolysin as add-on therapy. The primary objective was to assess the clinical efficacy of Cerebrolysin. The secondary objective was to investigate its effect on haemorrhagic transition and to confirm its safety profile.

RESULTS

Baseline characteristics of patients showed no significant differences between the two groups. No difference could be detected between the two groups in the mRS scale though the Cerebrolysin group showed descriptive superiority over the control group. We found a statistically significant difference considering haemorrhagic transition and mortality rate in favour of the Cerebrolysin group.

DISCUSSION

The multimodal neurotrophic agent Cerebrolysin holds promise to impact on the late consequences of a reperfusion syndrome. Its influence on reducing neuroinflammation, promoting neuronal cell viability and neurogenesis as well as the stabilising effect on the blood-brain barrier suggests a protective effect on the neurovascular unit even when no recanalisation occurs. We confirmed the excellent safety profile of Cerebrolysin.

CONCLUSION

Cerebrolysin as add-on therapy might be beneficial and safe for patients with acute stroke in terms of lowering risk for haemorrhagic complications after recanalisation therapy.

High-energy nanosecond parametric source at 2.7 µm

We report a high-energy nanosecond KTiOAsO₄-based optical parametric oscillator and amplifier system driven by a 1064-nm, injection-seeded, Q-switched Nd:YAG laser to provide mid-infrared pumping for few-cycle optical parametric chirped-pulse amplification operating in the long-wave infrared spectral regime. An output energy of 10.5 mJ at 2726 nm was obtained from the final power amplifier with a spectral width of 2.8 nm, pulse duration of 1.2 ns, and M² value of 2.4. The parametric source provides for the second mode of operation, where 10-ns pulses are produced by disabling the electro-optic slicing that enables the 1-ns mode. For 10-ns operation, the source produced energy of 25 mJ with a M² value of 2.8.

Prognostic value of mitral regurgitation in patients with asymmetric hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Introduction

Since mitral regurgitation (MR) is a very common finding in patients with hypertrophic cardiomyopathy (HCM), the evaluation of the mitral valve anatomy and the degree of MR is of utmost importance in this population. However, data regarding the prognostic value of different degrees of MR in HCM remains scarce.

Purpose

The aim of this study was to determine whether the presence of a higher degree of MR affects: 1) long term prognosis; 2) clinical and echocardiographic presentation of HCM patients.

Material and Methods

We included prospectively 102 patients, diagnosed with primary asymmetric HCM. The degree of MR was determined echocardiographicaly according to current recommendations of the American Association of Echocardiography. According to the MR severity, patients were divided into 2 groups: Group 1 (n = 52) with no/trace or mild MR and Group 2 with moderate or moderate to severe MR. All patients had clinical and echocardiographic examination, 24-hour Holter ECG and NT pro BNP analysis performed. The primary outcome was a composite of: 1) HCM related death or sudden death; 2) hospitalization due to acute heart failure; 3) sustained ventricular tachycardia; 4) ischemic stroke.

Results

Patients with higher MR degree had more frequent chest pain (p = 0.039), syncope (p = 0.041) and NYHA II functional class (p < 0.001). Group 2 patients had mostly obstructive form of HCM (p < 0.001) with more frequent presence of previous atrial fibrillation (AF) (p = 0.032), as well as the new onset of AF (p = 0.014) compared to patients in Group 1. Patients with higher MR degree had significantly more SAM (p < 0.001) resulting in a more frequent eccentric MR jet (p < 0.001), along with calcified mitral annulus (p = 0.007), enlarged left atrial volume index (p < 0.001), and elevated right ventricular pressure (p = 0.001). As a result of higher MR grade, Group 2 had higher E/e" values (p < 0.001), elevated LV filling pressure (lateral E/e’ >10), as well as higher levels of NT pro BNP (p = 0.001). By Kaplan-Meier analysis we demonstrated that the event free survival rate during follow up of median 75 (IQR 48-103) months was significantly higher in Group 1 compared to the Group 2 (79% vs. 46%, p < 0.001), Figure 1. After adjustment for relevant confounders, moderate/moderate to severe MR remained as an independent predictor of adverse outcome (hazard ratio 2.58, 95% CI: 1.08-6.13, p < 0.001).

Conclusion

Presence of moderate, or moderate to severe MR was associated with poor long-term outcome of HCM patients. These results indicate the importance of an adequate MR assessment and detailed evaluation of the mitral valve anatomy in the prediction of complications and adequate treatment of patients with HCM.

Abstract Figure.

Filament-induced breakdown spectroscopy with structured beams

Filament-induced ablation represents an attractive scheme for long-range material identification via optical spectroscopy. However, the delivery of laser energy to the target can be severely hindered by the stochastic nature of multiple-filamentation, ionization of ambient gas, and atmospheric turbulence. In order to mitigate some of these adverse effects, we examine the utility of beam shaping for femtosecond filament-induced breakdown spectroscopy with Gaussian and structured (Laguerre-Gaussian, Airy, and Bessel-Gaussian) beams in the nonlinear regime. Interaction of filaments with copper, zinc, and brass targets was studied by recording axially-resolved broadband emission from the filament-induced plasma. The laser-solid coupling efficacy was assessed by inferring thermodynamic parameters such as excitation temperature and electron density. While under our experimental conditions the ablation rate with Gaussian- and Laguerre-Gaussian beams is found to be similar, the Airy and Bessel-Gaussian beams offer the advantage of longitudinally extended working zones. These results provide insights into potential benefits of structuring ultrafast laser beams for standoff sensing applications.

Long term perspective with LBBB: role of stress echocardiography

Background

Previous studies have shown that left bundle branch block (LBBB), as a relatively common electrocardiographic (ECG) abnormality, represents the condition with often non benign and sometimes adverse outcome.

Purpose

The Aim of our study was to determine the predictive value of a stress echocardiography test in patients with LBBB.

Methods

Our study population included 189 patients (88 male, 46.6%, mean age 63.08±9.65) with diagnosed left bundle branch block who performed stress echocardiography (SECHO) according to Bruce protocol. Median follow-up of the patients was 56 months (IQR 48–71 months) for the occurrence of cardiovascular death and non-fatal myocardial infarction, repeat revascularization (coronary artery bypass grafting-CABG or percutaneous coronary intervention-PCI).

Results

Out of 189 patients, 32 (16.9%) patients had positive, while 157 (83.1%) patients had negative SECHO test. During the follow up period 28 patients had major adverse cardiac event: 1 nonfatal myocardial infarction, 6 heart failure hospitalizations, 5 CABGs, 8 PCIs, while 8 patients had cardiac death. Using the Cox regression analysis, univariate predictors of adverse cardiac events were diabetes mellitus (HR 4.530 [95% CI 1.355–15.141], p=0.014), PCI (HR 4.288 [95% [95% CI 2.010–9.144], p<0.001) and positive SECHO test (HR 2.289 [95% CI 1.006–5207], p=0.048). In the multivariate analysis only previous PCI remained independent predictor of adverse events (HR 3.650 [95% CI 1.665–8.003], p=0.001). p=0.048). Using the Kaplan-Meier survival curve the patients with negative SECHO had better outcome compared to patients with positive SECHO (140/160; 87,5% vs 21/29; 72.4%, p=0.035) and much longer event-free time (77.4±1.6 months vs 67.1±5.4 months, Log Rank 4.136, p=0.042)

Conclusion

Patients with LBBB and negative SEHO test have good prognosis. Patients with history of CAD and diabetes mellitus and LBBB are at increased risk for future events and need periodical reassessment.

Funding Acknowledgement

Type of funding source: None

Time-dependent improvement in coronary flow reserve in collateral donor artery following successful recanalization of the Coronary Chronic Total Occlusion

Background

Coronary chronic total occlusion (CTO) is characterized by the presence of collateral blood vessels which can provide additional blood supply to CTO-artery dependent myocardium. Successful CTO recanalization is followed by significant decrease in collateral donor artery blood flow and collateral derecruitment.

Purpose

Study aim was to assess time-dependent changes in coronary flow reserve (CFR) in collateral donor artery after CTO recanalization and identify factors that influence these changes.

Methods

Our study enrolled 31 patients with CTO scheduled for percutaneous coronary intervention (PCI). Non-invasive CFR was measured before PCI in collateral donor artery, and 24h and 6 months post-PCI in CTO and collateral donor artery. Gated SPECT MIBI was performed before PCI, while quality of life was assessed by Seattle angina questionnaire (SAQ) pre-PCI, and 6 months after PCI.

Results

Collateral donor artery showed significant increase in CFR 24h after CTO recanalization compared to pre-PCI values (2.30±0.49 vs. 2.71±0.45, p=0.005), which remained unchanged after 6 months (2.68±0.24). Maximum baseline blood flow velocity of the collateral donor artery showed significant decrease measured 24h post-PCI compared to pre-PCI values (0.28±0.06 vs. 0.24±0.04m/s), and remained similar after 6-months. There was no significant difference in maximum hyperemic blood flow velocity pre-PCI, 24h and 6 months post-PCI. CFR change of the collateral donor artery 24h post-PCI compared to pre-PCI values showed inverse correlation with left ventricle ejection fraction (LVEF) measured on SPECT. CFR changes showed no correlation with the changes in quality of life assessed by SAQ post-PCI compared to pre-PCI.

Conclusions

Significant increase in CFR of the collateral donor artery was observed within 24h after successful recanalization of CTO artery, which maintained constant after the 6 months follow-up. This increase was largely driven by the significant reduction in the maximum baseline blood flow velocity within 24h after CTO recanalization compared to pre-PCI values. Our results suggest that possible benefit of CTO recanalization could be the improvement in physiology of the collateral donor artery.

Funding Acknowledgement

Type of funding source: None

Hyperventilation echocardiography in INOCA: the HEROIC study

Background

Patients with ischemia and no obstructive coronary artery disease (INOCA) are a heterogeneous group and an unmet diagnostic challenge. Noninvasive Doppler is a feasible tool to assess coronary flow velocity (CFV) in left anterior descending coronary artery (LAD) during stress echocardiography (SE).

Aim

To assess CFV response during coronary vasoconstrictor and vasodilator stimuli in INOCA patients.

Methods

In a prospective single center study, we enrolled 16 INOCA patients (age 60±12 years, 15 females) with previously normal angiograms. All underwent SE testing with hyperventilation (HYP, respiratory rate of 30 per min for 5') followed by supine bicycle exercise (HYP+EXE); and adenosine CFV evaluation (ADO, 0.84 mg/kg in 1 min) on the other day. The ratio of peak/rest changes of CFV during HYP in LAD was taken as an index of vasoconstriction, and CFV reserve was evaluated after EXE. An abnormal response to HYP was a CFV ratio <1.0 (vasoconstrictor response). An abnormal response to ADO was a CFV reserve <2.0 (blunted vasodilatory response). CFVR at peak HYP+ EXE was an indicator of endothelial dependent vasodilatation.

Results

The double product increased during HYP, in comparison to rest (13 337 vs 9858, p<0.001), and further increase with EXE (21 118 vs HYP, p<0.001). Chest pain or dyspnea were present in 2/16 pts during HYP, and in 5/16 patients during HYP+EXE (12.5% vs 31.25%, p=0.083). ST segment depression (≥1mm) was present in 1/16 patients during HYP, and 3/16 during HYP+EXE. Two patients showed regional wall motion abnormalities with HYP+EXE. CFVR response was blunted in 9/16 patients during HYP+EXE, and abnormal for vasoconstriction during HYP in 6. Vasodilation during ADO was preserved in all patients. There was significant difference between CFVR response during HYP+EXE and ADO (1.9±0.5 vs 2.4±0.4 respectively, p=0.039), and between CFVR HYP and ADO (1.2±0.3 vs 2.4±0.4, p<0.001).

Conclusion

In INOCA patients, HYP+EXE is a more powerful ischemic stress than HYP alone and unmasks abnormalities in regional wall motion and/or CFV response in over one- half of patients, likely unmasking the underlying abnormal coronary vasomotor response of large epicardial and/ or small coronary vessels. INOCA patients show profound heterogeneity of coronary vasomotor responses which can be detected with a combined vasodilator - vasoconstrictor SE approach with CFV assessment. The clarification of underlying coronary microcirculatory heterogeneity is the prerequisite for a personalized treatment, and can be easily extracted from CFV-SE. Normal INOCA hearts are all alike, every abnormal heart is abnormal in its own way.

Funding Acknowledgement

Type of funding source: None

The prognostic value of coronary flow reserve of left anterior descending artery in non-diagnostic or inconclusive stress echocardiography tests

Background

Relevant number of all stress echocardiography results are non-diagnostic or inconclusive. Such importance cannot be ignored as previous studies have shown that these patients have higher risk for adverse events. Non-invasive transthoracic Doppler derived coronary flow reserve (CFR) of left anterior descending (LAD) artery, as additional test, is an effective tool to predict adverse cardiac events in various clinical settings.

Purpose

The aim of this study was to investigate the value of CFR of LAD in predicting outcome.

Methods

122 patients, (35,8% with previous MI) with nondiagnostic stress echocardiography results (target heart rate not reached, chest pain without ECG and echo changes) and with inconclusive stress echocardiography results (target heart rate reached, chest pain with ECG changes and without echo changes) were referred for transthoracic

Doppler echocardiographic CFR assessment of LAD. CFR was calculated as the ratio between maximal hyperemic and baseline coronary flow velocity. CFR ≤2 was considered abnormal. All patients were followed for major adverse cardiac events (MACE): nonfatal myocardial infarction, hospitalization, revascularization (CABG or PCI) and death.

Results

Measured values of CFR LAD were in the range 1,52- 4,00 (mean: 2,4±0.44). CFR LAD was abnormal in 22 (18%), and preserved in 100 patients (82%). During median follow-up of 23 months (interquartile range 9–35), 14 patients underwent revascularization (2 had CABG, 12 had PCI). There were no myocardial infarctions, hospitalizations or cardiovascular deaths in the follow-up period. Patients with lower CFR values (CFR≤2) had a higher event rate and shorter event free survival time compared to those with CFR>2, event rate (9/22, 40,9% vs 5/98 5,1%; p<0.0001) and event free time (22±3 vs 33±1 months; p<0.0001) by Kaplan Maier analyses, (Log Rank 24.42; p<0.001).

Conclusions

Preserved CFR of LAD (>2.0) predicts excellent survival in patients with non-diagnostic and inconclusive stress echocardiography.

Funding Acknowledgement

Type of funding source: None

P278 Does recanalization of chronic total occlusion reflect on myocardial function?

Background

Percutaneous coronary intervention for chronic total occlusion (PCI CTO) is still high risk procedure and it is doubtful will it become standard of care. There is evidence that it can reduce angina but even silent ischemia represent ischemic burden that ultimately lead to left ventricle remodeling and electrical instability.

Purpose

Our aim was to access effectiveness of percutaneous coronary intervention (PCI) when added to optimal medical therapy (OMT) on myocardial function.

Methods

We compared two groups of pts. First patients with percutaneous coronary intervention of chronic total occlusion with optimal medical therapy and second group - patients with only optimal medical therapy (control group). Echocardiographic exam was performed before randomization and after 6 months of follow-up. Doppler intervals- isovolumetric relaxation time (IVRT), isovolumetric contraction time (IVCT) and ejection time (ET) were measured. MPI (Myocardial performance index) is equal to the sum of the IVRT and IVCT divided by the ET. Velocity of early mitral wave (E) was divided by average peak early diastolic annular velocity (e"). Peak longitudinal strain was assessed in 17 left ventricular segments. Time intervals from start Q/R on electrocardiogram to peak negative strain during the cardiac cycle were assessed. Mechanical dispersion was defined as the standard deviation of this time intervals from 17 segments, reflecting myocardial contraction heterogeneity.

Results

A total of 94 age matched CTO patients (48 in PCI + OMT group and 46 in OMT) were analyzed. Changes in ejection fraction (EF), diastolic function represented by E/e", global cardiac function represented by MPI, global longitudinal strain (GLS) and myocardial dispersion changes were compared between groups. At follow up between groups in there was no significant change in ejection fraction (EF), diastolic function, GLS and mechanical dispersion, but there was improvement in MPI.

Conclusion

Myocardial performance index is sensitive marker which can detect subtle improvement in global myocardial function after recanalization of chronic total occlusion..

Variable PCI + OMT (n = 46) OMT (n = 48) ΔOMT vs. ΔPCI + OMT p value baseline At 6month follow up P value baseline At 6month follow up P value EF (%) 55.69 ± 8.56 54.83 ± 8.44 0.10 50.22 ± 11.71 51.42 ± 10.45 0.06 0.71 MPI 0.676 ± 0.99 0.632 ± 0.96 <0.01* 0.593 ± 0.14 0.604 ± 0.12 0.22 <0.01* E/e" 13.10 ± 6.90 12.05 ± 5,08 <0.05* 14,12 ± 5.70 13.02 ± 5.62 <0.05* 0.23 GLS (%) -14,38 ± 3,38 -15,22 ± 3,68 <0.05* -13.33 ± 3.43 -13.29 ± 3.42 0.87 0.07 Mechanical dispersion (ms) 63.89 ± 26.22 57.35 ± 27.33 <0.01* 53.30 ± 21.68 50.00 ± 22.40 0.05 0.06 Δ- percentage changes between baseline and at 6 month follow up

P302 Forgotten and neglected: LV hypertrophy and LV remodeling as important predictors in patients with mitral valve prolapse

Aim

of this study was to test whether LVH and distinctive LV geometry are coupled with increased risk for heart failure (HF) development and occurrence of major adverse cardiac event (MACE) among patients with MVP and can they improve power of statistical models for HF and MACE prediction based on parameters supported by the current guidelines.

Methods

376 pts diagnosed with mitral valve prolapse (MVP) between 1. January 2014. and 31. December 2017 and with complete medical chart and follow-up data from central echo laboratory in the tertiary health center were enrolled in the study. Four types of LV geometry were identified: Type 1 (normal LV mass with normal geometry), Type 2 (normal LV mass with concentric remodeling), Type 3 (eccentric hypertrophy) and Type 4 (concentric hypertrophy). The primary outcome was HF and secondary outcome was MACE (HF development, myocardial infarction, myocardial revascularisation (both PCI and/or ACBG) and cardiac death).

Results

The distribution of patients was as follow: 51.2% (Group 1) vs 3.3% (Group 2) vs 41.4 % (Group 3) vs 4.1% (Group 4). In multivariable model the highest OR for HF development after adjustment for age, ESD and LVH, had concentric LVH (OR= 5.361, p= 0.004, 95% CI 1.696-16.648), then EF < 60% (OR= 3.025, p = 0.004, 95% CI 1.427-6.411) and the lowest OR had SPAP > 40 mmHg (OR = 2.274, p = 0.039, 95% 1.43-4.958). Adding LVH significantly increased model’s power to predict HF above traditional parameters (Chi-square from 19.386 to 23.640, p < 0.001; Nagelkerke R square from 0.090 to 0.110), whereas addition of LV geometry increased it even more (Chi-square from 23.640 to 28.729, p < 0.001; Negelkerke R square from 0.110 to 0.132). Independent MACE predictors in multivariable model were: EF < 60% (OR 3.645, p < 0.001, 95% CI 1.808- 7.50), new onset atrial fibrillation during the follow-up (OR =3.327, p = 0.012, 95% CI 0.305-8.484), concentric LVH (OR= 4.241, p = 0.015, 95% CI 1.327-13.550) and normal LV geometry without LVH (OR= 0.514, p = 0.002, 95% CI 0.288-0.918), even after adjustment for MV surgery. Adding LVH significantly improved model’s power (Chi-square from 29.026 to 35.112, p < 0.001; Nagelkerke R square 0.121 to 0.146) to predict MACE and addition of type of LV geometry provided additional strength (Chi-square from 35.112 to 39.707, p < 0.001; Nagelkerke R square from 0.146 to 0.164).

Conclusion

LVH and especially concentric LVH are independent predictors of heart failure development and MACE in mitral valve prolapse and significantly improves predictive powers of the models based on traditional parameters.

P2758Role of echocardiographic findings and blood culture in embolic complications in patients with infective endocarditis

Aims

Aims of the study were to analyse: 1) relation between embolic complications of IE and structural changes of the heart detected by echocardiography in IE patients; 2) association between embolic complications of IE and IE causative microorganism.

Methods

335 patients with definitive IE from the single tertiary center were enrolled in the study between 2009–2018. Echocardiographic changes are defined in accordance with 2015 ESC guideline. Associations between embolic complication and structural heart changes, as well as between

IE causative microorganism and embolic complications were tested by Chi square test.

Results

Observed embolic complication were: ischemic stroke (in 12.5% of patients), haemorrhagic stroke (2.1%), neuroinfection (9.6%), brain abscess (1.8%), discitis (3%), pulmonary embolism (1.5%), spleen abscess (7.8%) and peripheral arterial embolization (1.5%). There were several significance associations: vegetations larger than 15 mm were associated with ischemic stroke (p=0.041) and peripheral arterial embolization (p=0.05); perivalvular abscess was associated with brain abscess (p=0.037) and peripheral arterial embolization (p=0.019). Staphylococcus aureus isolated from blood cultures was associated with discitis (p<0.001), brain abscess (p<0.001) and neuroinfection (p<0.001). Bacterias from HACEK group were associated with peripheral arterial embolisation (p<0.001) and non-HACEK bacterias were associated with ichemic stroke (p=0.016). Patients with more than one isolated bacteria from blood culture had more often spleen abscess (p=0.003) and ichemic stroke (p=0.049).

Conclusion

Results point that large vegetations, but also perivalvular abscesses are coupled with higher rate of embolic complications in patients with IE. Staphylococcus aureus, HACEK group and non-HACEK bacteria are, more than other causative IE microorganisms, associated with embolism. These results might be clinically important for treatment chose and prognosis of the patients with IE.

P1511Promising prognostic value of negative stress echocardiography in patients with incomplete revascularization after successful primary PCI

Background

The specific role of non-invasive functional testing in a risk stratification of patients with incomplete revascularization after primary percutaneous coronary intervention (pPCI) still needs to be evaluated. The aim of our study was to assess negative prognostic value of stress echocardiography (SECHO) after successful pPCI and incomplete revascularization of non-culprit lesions.

Methods

Our study consisted of 202 patients (mean age 59±10 years, male 142) successfully treated with pPCI, who performed SECHO according to Bruce protocol in order to assess residual ischemia in coronary artery with non-culprit lesion. Duke treadmill score, functional capacity (Metabolic Equivalents - METs), achieved target heart rate (THR), heart rate recovery (HRR), wall motion score index (WMSI) and ejection fraction were interrogated in all patients. Slow HRR was defined as ≤18 beats/min. Median follow-up of the patients was 70 months (IQR 55–83 months) for the occurrence of cardiovascular death and non-fatal myocardial infarction. We also assessed the independent predictors for the occurrence of the adverse events.

Results

Out of 202 patients, 42 (20.8%) had positive SECHO test, 4 patients (1.98%) had died due to non-cardiac causes and 7 patients (3.5%) were lost to follow-up. From the remaining 149 patients with negative SECHO, 13 (8.7%) had an adverse event (7 cardiovascular deaths and 6 non-fatal MI). Negative predictive value of SECHO test was 91.3%. Univariate predictors of adverse events were slow HRR (HR 4.343 [95% CI 1.473–14.011], p=0.008), and not achieved THR (HR 0.322 [95% CI 0.105–0.985], p=0.047). By multivariate analysis, only slow HRR remained independent predictor of adverse events (HR 3.324 [95% CI 1.013–10.906], p=0.048).

Conclusion

SECHO test has excellent negative prognostic value in patients with incomplete revascularization of non-culprit lesions after successful pPCI. Still, particular care should be taken to the patients with slow HRR and negative SECHO due to increased risk for the occurrence of adverse events.

Acknowledgement/Funding

Ministry of Education and Science of the Republic of Serbia (Grant No III41022)

Physical conditions for UO formation in laser-produced uranium plumes

We investigate the oxidation of uranium (U) species, the physical conditions leading to uranium monoxide (UO) formation and the interplay between plume hydrodynamics and plasma chemistry in a laser-produced U plasma. Plasmas are produced by ablation of metallic U using nanosecond laser pulses. An ambient gas environment with varying oxygen partial pressures in 100 Torr inert Ar gas is used for controlling the plasma oxidation chemistry. Optical emission spectroscopic analysis of U atomic and monoxide species shows a reduction in the emission intensity and persistence with increasing oxygen partial pressure. Spectral modelling is used for identifying the physical conditions in the plasma that favor UO formation. The optimal temperature for UO formation is found to be in the temperature range of ∼1500-5000 K. The spectrally integrated and spectrally filtered (monochromatic) imaging of U atomic and molecular species reveals the evolutionary paths of various species in the plasma. Our results also highlight that oxidation in U plasmas predominantly occurs at the cooler periphery and is delayed with respect to plasma formation, and the dissipation of molecular species strongly depends on oxygen partial pressure.

Orodispersible minitablets of enalapril for use in children with heart failure (LENA): Rationale and protocol for a multicentre pharmacokinetic bridging study and follow-up safety study

Introduction

Treatment of paediatric heart failure is based on paradigms extensively tested in the adult population assuming similar underlying pathophysiological mechanisms. Angiotensin converting enzyme inhibitors (ACEI) like enalapril are one of the cornerstones of treatment and commonly used off-label in children. Dose recommendations have been extrapolated from adult experience, but the relationship between dose and pharmacokinetics (PK) in (young) children is insufficiently studied. Furthermore, appropriate paediatric formulations are lacking. Within the European collaborative project LENA, a novel formulation of enalapril orodispersible minitablets (ODMT), suitable for paediatric administration, will be tested in (young) children with heart failure due to either dilated cardiomyopathy or congenital heart disease in two pharmacokinetic bridging studies. Paediatric PK data of enalapril and its active metabolite enalaprilat will be obtained. In a follow-up study, the safety of enalapril ODMTs will be demonstrated in patients on long-term treatment of up to 10 months. Furthermore, additional information about pharmacodynamics (PD) and ODMT acceptability will be collected in all three studies.

Methods and Analysis

Phase II/III, open-label, multicentre study. Children with dilated cardiomyopathy (DCM) (n = 25; 1 month to less than 12 years) or congenital heart disease (CHD) (n = 60; 0 to less than 6 years) requiring or already on ACEI will be included. Exclusion criteria include severe heart failure precluding ACEI use, hypotension, renal impairment, hypersensitivity to ACEI. For those naïve to ACEI up-titration to an optimal dose will be performed, those already on ACEI will be switched to an expected equivalent dose of enalapril ODMT and optimised. In the first 8 weeks of treatment, a PK profile will be obtained at the first dose (ACEI naïve patients) or when an optimal dose is reached. Furthermore, population PK will be done with concentrations detected over the whole treatment period. PD and safety data will be obtained at least at 2-weeks intervals. Subsequently, an intended number of 85 patients will be followed-up up to 10 months to demonstrate long-term safety, based on the occurrence of (severe) adverse events and monitoring of vital signs and renal function.

Ethics and dissemination

Clinical Trial Authorisation and a favourable ethics committee opinion were obtained in all five participating countries. Results of the studies will be submitted for publication in a peer-reviewed journal.

Trial registration numbers

EudraCT 2015-002335-17, EudraCT 2015-002396-18, EudraCT 2015-002397-21.

Pharmacotherapeutic management of paediatric heart failure and ACE-I use patterns: a European survey

OBJECTIVE

To characterise heart failure (HF) maintenance pharmacotherapy for children across Europe and investigate how angiotensin-converting enzyme inhibitors (ACE-I) are used in this setting.

METHODS

A Europe-wide web-based survey was conducted between January and May 2015 among European paediatricians dedicated to cardiology.

RESULTS

Out of 200-eligible, 100 physicians representing 100 hospitals in 27 European countries participated. All participants reported prescribing ACE-I to treat dilated cardiomyopathy-related HF and 97% in the context of congenital heart defects; 87% for single ventricle physiology. Twenty-six per cent avoid ACE-I in newborns. Captopril was most frequently selected as first-choice for newborns (73%) and infants and toddlers (66%) and enalapril for children (56%) and adolescents (58%). Reported starting and maintenance doses varied widely. Up to 72% of participants follow formal creatinine increase limits for decision-making when up-titrating; however, heterogeneity in the cut-off points selected existed. ACE-I formulations prescribed by 47% of participants are obtained from more than a single source. Regarding symptomatic HF maintenance therapy, 25 different initial drug combinations were reported, although 79% select a regimen that includes ACE-I and diuretic (thiazide and/or loop), 61% ACE-I and aldosterone antagonist; 44% start with beta-blocker, 52% use beta-blockers as an add-on drug. Of the 89 participants that prescribe pharmacotherapy to asymptomatic patients, 40% do not use ACE-I monotherapy or ACE-I-beta-blocker two-drug only combination.

CONCLUSIONS

Despite some reluctance to use them in newborns, ACE-I seem key in paediatric HF treatment strategies. Use in single ventricle patients seems frequent, in apparent contradiction with current paediatric evidence. Disparate dosage criteria and potential formulation-induced variability suggest significant differences may exist in the risk-benefit profile children are exposed to. No uniformity seems to exist in the drug regimens in use. The information collected provides relevant insight into real-life clinical practice and may facilitate research to identify the best therapeutic options for HF children.

Electrical conductance of near-infrared femtosecond air filaments in the multi-filament regime

Electrical conductive properties of femtosecond laser filaments are of significant interest for applications such as remote arc suppression and discharge guiding. We transmitted electrical current through a DC-biased air plasma channel formed in the wake of an energetic femtosecond laser pulse and observed an increased rate of change of the charge transmitted through the ionized channel with laser energy when crossing from the single- to multi-filament regimes. This behavior is attributed to the confluent effects of greater electron density and an increased cross-sectional area of the multi-filament plasma structures. As the laser energy is increased, the formation of additional conductive channels in the multi-filamentation regime becomes a significant contributor to the rapid increase of conductivity. These observations suggest a potential path to attractive applications such as efficient energy transfer in air mediated by femtosecond laser-produced filaments.

Optical emission from ultrafast laser filament-produced air plasmas in the multiple filament regime

We perform optical emission spectroscopy of ultrafast laser filament-produced air plasmas in the multiple filament regime at driving wavelengths of 400 nm and 800 nm. The spatiotemporal structure of the emission from the plasmas are observed and the emission spectra are used to estimate plasma temperature and density for a range of laser parameters. Plasma temperatures are determined from the molecular nitrogen fluorescence, while the electron densities are estimated from Stark broadening of the oxygen-I 777.19-nm line. Electron temperatures are determined to be in the range of 5000-5200 K and they do not vary significantly along the length of the filament, nor are they sensitive to incident laser energy or wavelength. Electron densities are on order of 10¹⁶ cm^-3 and show a greater variation with axial position, laser energy, and laser wavelength. We discuss mechanisms responsible for spatial localization of emitting species within the filament. Optical emission spectroscopy offers a simple, non-perturbing method to measure filament properties, that allows the information on the associated molecular transitions and excitation/ionization mechanisms to be extracted.

Tracking of oxide formation in laser-produced uranium plasmas

We use a spatially and temporally resolved emission tracking technique based on optical emission spectroscopy to map the evolution of emission features from uranium and its compounds in a plasma produced by a nanosecond laser. We observe quenching of the emission from neutral uranium (591.538 nm) and uranium monoxide (593.55 nm) species with increasing oxygen concentration and discuss possible reaction pathways for dissociation or formation of higher uranium oxides (U_xO_y). We further identify spectral features between 320 nm and 380 nm and between 520 nm and 640 nm, which we attribute to U_xO_y.

Ultrafast Laser Filament-induced Fluorescence Spectroscopy of Uranyl Fluoride

Uranyl fluoride (UO2F2) is a compound which forms in the reaction between water and uranium hexafluoride, a uranium containing gas widely used for uranium enrichment. Uranyl fluoride exhibits negligible natural background in atmosphere; as a result, its observation implies the presence and active operation of nearby enrichment facilities and could be used as a tracer for treaty verification technologies. Additionally, detection of UO2F2 has a potential application in guiding remediation efforts around enrichment facilities. Laser-induced fluorescence (LIF) has been proposed in the past as a viable technique for the detection and tracking of UO2F2. We demonstrate that ultrafast laser filamentation coupled with LIF extends the capabilities of standard LIF to enable remote detection of UO2F2. An intense femtosecond laser pulse propagated in air collapses into a plasma channel, referred to as a laser filament, allowing for the extended delivery of laser energy. We first investigate the luminescence of UO2F2 excited by the second harmonic of an ultrafast Ti:sapphire laser and subsequently excite it using the conical emission that accompanies ultrafast laser filamentation in air. We measure the decay rates spanning 4.3-5.6 × 104 s-1 and discuss the characteristics of the luminescence for both ultrafast- and filament-excitation. Larger decay rates than those observed using standard LIF are caused by a saturated component of prompt decay from annihilation of dense excited states upon excitation with an ultrafast source. The reproducibility of such decay rates for the given range of incident laser intensities 1.0-1.6 × 1011 W cm-2 is promising for the application of this technique in remote sensing.

Intense laser filament-solid interactions from near-ultraviolet to mid-infrared

Studies of high-power ultrashort laser pulse interaction with matter are not only of fundamental scientific interest, but are also highly relevant to applications in the domain of remote sensing. Here, we investigate the effect of laser wavelength on coupling of femtosecond laser filaments to solid targets. Three central wavelengths have been used to produce filaments: 0.4, 0.8, and 2.0 µm. We find that, unlike the case of conventional tight focusing, use of shorter wavelengths does not necessarily produce more efficient ablation. This is explained by increased multi-photon absorption arising in near-UV filamentation. Investigations of filament-induced plasma dynamics and its thermodynamic parameters provide the foundation for unveiling the interplay between wavelength-dependent filament ablation mechanisms. In this way, strategies to increase the sensitivity of material detection via this technique may be better understood, thereby improving the analytical performance in this class of applications.

Transition of Femtosecond-Filament-Solid Interactions from Single to Multiple Filament Regime

High-peak-power fs-laser filaments offer unique characteristics attractive to remote sensing via techniques such as remote laser-induced breakdown spectroscopy (R-LIBS). The dynamics of several ablation mechanisms following the interaction between a filament and a solid determines the emission strength and reproducibility of target plasma, which is of relevance for R-LIBS applications. We investigate the space- and time-resolved dynamics of ionic and atomic emission from copper as well as the surrounding atmosphere in order to understand limitations of fs-filament-ablation for standoff energy delivery. Furthermore, we probe the shock front produced from filament-target interaction using time-resolved shadowgraphy and infer laser-material coupling efficiencies for both single and multiple filament regimes through analysis of shock expansion with the Sedov model for point detonation. The results provide insight into plasma structure for the range of peak powers up to 30 times the critical power for filamentation P cr . Despite the stochastic nucleation of multiple filaments at peak-powers greater than 16 P cr , emission of ionic and neutral species increases with pump beam intensity, and short-lived nitrogen emission originating from the ambient is consistently observed. Ultimately, results suggest favorable scaling of emission intensity from target species on the laser pump energy, furthering the prospects for use of filament-solid interactions for remote sensing.

Implementation of Congenital Heart Diseases Screening at the Bihac Cantonal Hospital

Introduction:

Congenital heart defects (CHD) were the most common birth defects, and the most common cause of death in infants with congenital anomalies in developed countries. Early detection of these anomalies would greatly enhance the effect of therapeutic procedures and the final outcome. Lately, pulse oximetry (PO) is used for the purpose of screening the cyanotic congenital heart defects. PO in combination with the clinical examination has greater diagnostic sensitivity in detection of CHD.

Objective:

Application of PO screening in combination with a novel clinical examination methodology of cardiovascular system in neonate towards earlier detection of CHD.

Patients and methods:

Study included newborn children in Bihac Cantonal Hospital in the year 2012. The sample included 1,865 children. A total of 29 children with congenital heart disease was diagnosed during the neonatal period.

Conclusion:

Modern algorithm for early detection can significantly improve the diagnosis of congenital heart anomalies. Early detection allows optimal care for these children. This concept is simple, inexpensive and reproducible in most maternity wards.

Modern Strategy for Identification of Congenital Heart Defects in the Neonatal Period

Introduction:

Congenital heart defects are the most common congenital anomalies and occur with an incidence from 0.8 to 1% per 1000 live births. In recent years, the pulse oximetry has become a strong candidate for detecting cyanogen congenital heart defects and in combination with routine clinical exam can improve diagnostic of congenital heart diseases.

Objective:

To apply the modern algorithm for early detection of congenital heart defects in order to improve the diagnosis in the neonatal period.

Patients and Methods:

This was a prospective study that included children born in Bihac Cantonal Hospital during 2012. The diagnostic algorithm included a clinical examination of the newborn, measuring of transcutaneous oxygen saturation with the pulse oximeter between 24 and 48 hours of life, and, in some cases, additional tests (cardiac ultrasound).

Results:

A total of 1,865 children were examined. The application of diagnostic protocol identified the existence of congenital heart defects in 29 children. In re-evaluating the auscultator and ultrasound findings, we identified congenital heart defects in 19 children.

Conclusion:

The application of the modern algorithm for early detection of congenital heart diseases in the neonatal period can significantly improve the making of diagnosis of these anomalies. The concept is simple, inexpensive and applicable in most maternity wards.

Availability of Oral Formulations Labeled for Use in Young Children in Serbia, Germany and the USA

BACKGROUND

The paucity of marketed drug products that have been adequately studied in infants and children and subsequently, licensed (or labeled) for pediatric use has caused abundant use of off-label and unauthorized products in this patient population. In those instances where insufficient pharmacologic or therapeutic information exists for children, the potential for off-label use of medicines to result in therapeutic misadventure does as well. In the USA, a series of regulatory measures have been introduced since 1997 which have increased both the number and scope of pediatric drug trials and also, fostered the development of ageappropriate drug formulations by pharmaceutical companies. Provisions of these regulations for previously marketed drugs include the potential for a company to be granted 6 months of marketing exclusivity, thereby providing them with a financial incentive. For new drugs being developed that have potential pediatric use, the regulations mandate the inclusion of children in the drug development process. In the EU comparable measures have been very recently (Jan 2007) signed into European law to overcome the therapeutic orphan status of the infants and children of Europe.

METHOD

The aims of this study was to compare the availability of age-appropriate oral formulations labeled for use in children less than 12 years of age in Serbia, Germany and USA in 2007, and to investigate if certain drug groups of therapeutic importance to children had fewer medicines appropriately labeled for pediatric patients available. The primary sources of information for determining the ageappropriate oral dosage forms, and their licensing and labeling status were the official manuals on drug information and national formularies in 2007.

FINDING

The general availability of oral drugs was the highest in the USA (304), followed by Germany (235) and Serbia (156). From all these oral drugs the availability of labeled age-appropriate pediatric dosage formulations was only between 21.2% and 47.7%. Moreover, there were striking differences between the three countries in the availability of labeled age-appropriate formulations for certain drug groups such as cardiovascular (absent in Serbia) and antiparasitic drugs (absent in Serbia and Germany).

INTERPRETATION

Our data suggest that significant country-to-country differences continue to exist in both the number and type of oral drug formulations that have pediatric labeling. Potential contributing factors include country-specific differences in the drug regulatory process, capacity for pharmaceutical development and the regulatory lag time associated with the implementation of drug regulation specifically addressing pediatric product development and labeling. We hypothesize that the new European regulation concerning medicines and children will improve the current unacceptable situation.

Differences in speech and language abilities between children with 22q11.2 deletion syndrome and children with phenotypic features of 22q11.2 deletion syndrome but without microdeletion

BACKGROUND

22q11.2DS is the most common microdeletion syndrome in humans, usually associated with speech and language delay (SLD). Approximately 75% of children with 22q11.2 microdeletion have congenital heart malformations (CHM) which after infant open-heart surgery might lead to SLD.

AIMS

The purpose of this study was to determine whether factors associated with microdeletion contribute to SLD in children with 22q11.2DS.

METHODS AND PROCEDURES

We compared speech and language abilities of two groups of school-aged children: those with 22q11.2 microdeletion (E1) and those with the phenotype resembling 22q11.2DS but without the microdeletion (E2). An age-matched group of typically developing children was also tested.

OUTCOMES AND RESULTS

The obtained results revealed that children from group E1 have lower level of speech and language abilities compared to children from group E2 and control group. Additionally, mild to moderate SLD was detected in children from group E2 compared to children from the control group.

CONCLUSIONS AND IMPLICATIONS

The obtained results imply that both CHM after infant open-heart surgery and other factors associated with 22q11.2 microdeletion, contribute to SLD in patients with 22q11.2 microdeletion. Based on this, we could postulate that there is/are some potential candidate gene(s), located in the 22q11.2 region, whose function could be important for speech and language development.

Heart failure pharmacotherapy: differences between adult and paediatric patients

During the last decades, the introduction of new, more efficient drugs, has significantly improved the heart failure (HF) therapy of adults. Therapeutic focus has shifted from simple hemodynamic manipulation to include neurohumoral modulation as a consequence of the better understanding of mechanisms of HF formation, in particular at the cellular level. The aetiologies of HF in children are remarkably different and more varied than in the adult population. Cardiac failure is usually caused by congenital heart disease and cardiomyopathy in children, whereas in adults, coronary artery disease, hypertension and myocardial infarction are the most common causes. Despite this fact, pharmacotherapy of children is based on the same drugs, usually extrapolated from adult HF regimens. A recently published study in children treated with the drugs known to be efficient in adult HF therapy, provides encouragement that the outcomes might be similarly beneficial. On the other hand, some reports outline that children with HF, especially patients with systemic right ventricles or single ventricle physiology, require specific drug guidelines. A general characteristic of HF pharmacotherapy in children is the lack of paediatrically designed drugs. Drugs currently used in the treatment of HF in paediatric patients are designed for adults, and their efficacy, safety and quality have generally not been confirmed by clinical studies of children. Aside from this, availability of commercial paediatric drug formulations labelled for treatment of HF in children significantly influences the quality and efficacy of therapy.

Subtelomeric screening in Serbian children with dysmorphic features and unexplained developmental delay/intellectual disabilities

Developmental delay and intellectual disabilities (DD/ID) are significant health problems affecting 3% of the human population. Submicroscopic chromosomal rearrangements involving subtelomeric regions are often considered to be the cause of unexplained DD/ID. Screening of subtelomeric regions was performed in 80 unrelated patients with DD/ID and normal GTG-banded chromosomes using the MLPA method with two kits (SALSA P070-B1 and P036-E1). The MLPA screening revealed subtelomeric chromosome aberrations in four cases (5%). The aberrations detected were: 1p deletion, 1p deletion combined with 12q duplication, 4p deletion, and 9p deletion combined with 15q duplication. The deletions detected were classified as causative for the patients' observed phenotypes. This study confirms the high frequency of subtelomeric rearrangements in unexplained DD/ID and reinforces the argument for routine subtelomeric screening in order to get a correct diagnosis, establish genotype-phenotype correlations and offer accurate genetic counseling.

First measurement of the ionization yield of nuclear recoils in liquid argon

This Letter details a measurement of the ionization yield (Q(y)) of 6.7 keV(40)Ar atoms stopping in a liquid argon detector. The Q(y) of 3.6-6.3 detected e(-)/keV, for applied electric fields in the range 240-2130 V/cm, is encouraging for the use of this detector medium to search for the signals from hypothetical dark matter particle interactions and from coherent elastic neutrino-nucleus scattering. A significant dependence of Q(y) on the applied electric field is observed and explained in the context of ion recombination.