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Emergency Medical Services (EMS) are vital for providing timely out‐of‐hospital care during medical emergencies. This research aims to optimize ambulance services by strategically allocating resources to minimize response time. A modified Whale Optimization Algorithm (mWOA) is introduced to achieve this goal, focusing on providing 24 × 7 services to every patient in need. The, conducted in Southern Delhi, India, considers the uncertain and stochastic nature of demand and traffic. The results demonstrate a 14.6% improvement in average EMS‐based response time, highlighting the effectiveness of the mWOA algorithm in enhancing ambulance allocation strategies. The results obtained using different algorithms are compared with those obtained using mWOA. The experiment outcomes demonstrate that the mWOA has higher efficiency and superiority than alternative algorithms regarding convergence rate and stability. [ABSTRACT FROM AUTHOR]

Polymer nanocomposites have been utilized for wound healing applications. Compared to the conventional polymer composites, conducting polymer nanocomposites comprising a blend of biocompatible polymers with electroconductive and antibacterial nanofillers such as graphene‐based nanomaterials and metal/metal oxides, have attracted great attention in this arena due to enhanced physical, electrical and biological characteristics. Herein, polyvinyl alcohol (PVA)/chitosan (CS)/graphene oxide/zinc oxide electroconductive and antibacterial composite hydrogel films were fabricated by solution casting technique, for wound healing applications. The physicochemical and conductivity studies were carried out for all the polymer samples. The successful incorporation of the nanofillers and their even distribution into the PVA‐CS matrix was validated by the scanning electron microscopy‐EDAX, x‐ray diffractometer, Fourier‐transform infrared, and Raman analytical results. An enhancement in the surface roughness of the nanofiller incorporated composite film was elucidated by the topographical images obtained from AFM analysis. The composite with higher concentration of nanofillers exhibited a maximum conductivity of 0.35 × 10−4 Scm−1 compared to the other fabricated composites. A good antibacterial efficacy, minimal hemolytic activity as well as better thrombogenicity were portrayed by the composite films. Additionally, the nanocomposite films exhibited no cytotoxicity and excellent cell attachment and proliferation of RAW 264.7 cells. Therefore, based on the obtained results, it can be concluded that the composite with higher particle concentration, is an ideal candidate for futuristic wound dressing applications with electroconductivity, antimicrobial activity, hemostatic ability, and biocompatibility. Highlights: Fabrication of polyvinyl alcohol (PVA)/chitosan (CS)/GO‐ZnO hydrogel films by solvent‐castingA maximum conductivity of 0.35 × 10−4 S/cm obtained for the composite filmExhibited good antibacterial efficacy and minimal hemolytic activityBetter thrombogenicity and cytocompatibility portrayed by the compositeAn ideal candidate for futuristic wound dressing applications [ABSTRACT FROM AUTHOR]

The emergence of multidrug resistance (MDR) in bacterial pathogens is a serious public health concern. A significant therapeutic target for MDR infections is the quorum sensing‐regulated bacterial pathogenicity. Determining the anti‐quorum sensing abilities of certain medicinal plants against bacterial pathogens as well as the in‐silico interactions of particular bioactive phytocompounds with QS and biofilm‐associated proteins were the objectives of the present study. In this study, 6 medicinal plants were selected based on their ethnopharmacological usage, screened for Anti‐QS activity and Artemisia annua leaf extract (AALE) demonstrated pigment inhibitory activity against Chromobacterium violaceum CV12472. Further, the methanol active fraction significantly inhibited the virulence factors (pyocyanin, pyoverdine, rhamnolipid and swarming motility) of Pseudomonas aeruginosa PAO1 and Serratia marcescens MTCC 97 at respective sub‐MICs. The inhibition of biofilm was determined using a microtiter plate test and scanning electron microscopy. Biofilm formation was impaired by 70%, 72% and 74% in P. aeruginosa, C. violaceum and S. marcescens, respectively at 0.5xMIC of the extract. The phytochemical content of the extract was studied using GC–MS and 1, 8‐cineole was identified as major bioactive compound. Furthermore, 1, 8‐cineole was docked with quorum sensing (QS) proteins (LasI, LasR, CviR, and rhlR) and biofilm proteins (PilY1 and PilT). In silico docking and dynamics simulations studies suggested interactions with QS‐receptors CviR', LasI, LasR, and biofilm proteins PilY1, PilT for anti‐QS activity. Further, 1, 8‐cineole demonstrated 66% and 51% reduction in violacein production and biofilm formation, respectively to validate the findings of computational analysis. Findings of the present investigation suggests that 1, 8‐cineole plays a crucial role in the QS and biofilm inhibitory activity demonstrated by Artemisia annua extract. Research Highlights: Artemisia annua leaf extract (AALE) methanol fraction demonstrated broad‐spectrum QS and biofilm inhibitionScanning electron microscopy (SEM) confirmed biofilm inhibitionMolecular docking and simulation studies suggested positive interactions of 1,8‐cineol with QS‐receptors and biofilm proteins [ABSTRACT FROM AUTHOR]

The photovoltaic (PV) cells are highly sensitive to temperature variations. The linear variation of PV cells with operating temperature could lead to the loss of conversion efficiency and permanent damage of PV material. To address this critical issue, while improving the performance of solar photovoltaic system (SPVS) during the operating period, the deployment of a proper cooling system is a prime requisite in the design process. Considering this, two new and cost‐effective cooling techniques are proposed in this study, which can improve efficiency and increase the life of the PV panel. The first technique is the active cooling design with water. The proposed design enhances the access to PV cells to maximize cooling. The second one is an improved passive cooling technique that uses fins mounted on the backside of PV module. This further reduces the temperature by increasing the heat dissipation. Additionally, a third PV module without any cooling system is deployed as a reference margin. The techniques have been experimentally evaluated and a recommendation is made in order to reduce the temperature variation across the PV panel. [ABSTRACT FROM AUTHOR]

Development of multidrug resistance among pathogens has become a global problem for chemotherapy of bacterial infections. Extended-spectrum β-lactamase- (ESβL-) producing enteric bacteria and methicillin-resistant Staphylococcus aureus (MRSA) are the two major groups of problematic MDR bacteria that have evolved rapidly in the recent past. In this study, the aqueous extract of Murraya koenigii leaves was used for synthesis of silver nanoparticles. The synthesized MK-AgNPs were characterized using UV-vis spectroscopy, FTIR, XRD, SEM, and TEM, and their antibacterial potential was evaluated on multiple ESβL-producing enteric bacteria and MRSA. The nanoparticles were predominantly found to be spheroidal with particle size distribution in the range of 5–20 nm. There was 60.86% silver content in MK-AgNPs. Evaluation of antibacterial activity by the disc-diffusion assay revealed that MK-AgNPs effectively inhibited the growth of test pathogens with varying sized zones of inhibition. The MICs of MK-AgNPs against both MRSA and methicillin-sensitive S. aureus (MSSA) strains were 32 μg/ml, while for ESβL-producing E. coli, it ranged from 32 to 64 μg/ml. The control strain of E. coli (ECS) was relatively more sensitive with an MIC of 16 μg/ml. The MBCs were in accordance with the respective MICs. Analysis of growth kinetics revealed that the growth of all tested S. aureus strains was inhibited (∼90%) in presence of 32 μg/ml of MK-AgNPs. The sensitive strain of E. coli (ECS) showed least resistance to MK-AgNPs with >81% inhibition at 16 μg/ml. The present investigation revealed an encouraging result on in vitro efficacy of green synthesized MK-AgNPs and needed further in vivo assessment for its therapeutic efficacy against MDR bacteria. [ABSTRACT FROM AUTHOR]

Introduction: Atrial fibrillation (AF) is increasing in prevalence and is associated with significant morbidity and mortality. The optimal diagnostic and treatment strategies for AF are continually evolving and care for patients requires confidence in integrating these new developments into practice. These clinical practice guidelines will assist Australian practitioners in the diagnosis and management of adult patients with AF. Main recommendations: These guidelines provide advice on the standardised assessment and management of patients with atrial fibrillation regarding: screening, prevention and diagnostic work-up; acute and chronic arrhythmia management with antiarrhythmic therapy and percutaneous and surgical ablative therapies; stroke prevention and optimal use of anticoagulants; and integrated multidisciplinary care. Changes in management as a result of the guideline: Opportunistic screening in the clinic or community is recommended for patients over 65 years of age. The importance of deciding between a rate and rhythm control strategy at the time of diagnosis and periodically thereafter is highlighted. β-Blockers or non-dihydropyridine calcium channel antagonists remain the first line choice for acute and chronic rate control. Cardioversion remains first line choice for acute rhythm control when clinically indicated. Flecainide is preferable to amiodarone for acute and chronic rhythm control. Failure of rate or rhythm control should prompt consideration of percutaneous or surgical ablation. The sexless CHA2DS2-VA score is recommended to assess stroke risk, which standardises thresholds across men and women; anticoagulation is not recommended for a score of 0, and is recommended for a score of ≥ 2. If anticoagulation is indicated, non-vitamin K oral anticoagulants are recommended in preference to warfarin. An integrated care approach should be adopted, delivered by multidisciplinary teams, including patient education and the use of eHealth tools and resources where available. Regular monitoring and feedback of risk factor control, treatment adherence and persistence should occur. [ABSTRACT FROM AUTHOR]

Abstract: Background: The left ventricular (LV) papillary muscles are important components of the mitral valve apparatus. Catheter ablation of ventricular arrhythmias from these sites is challenging. We aim to describe the association between LV papillary muscle ventricular arrhythmias (VAs) and mitral valve prolapse (MVP), and to determine the outcomes of ablation in these patients with a focus on those with MVP and cardiomyopathy. Methods: A total of 152 patients underwent 170 consecutive procedures for ablation of focal VAs. MVP and cardiomyopathy were diagnosed by echocardiography. Outcomes following ablation were assessed in three groups: (1) LV papillary muscle VAs versus other sites, (2) LV papillary muscle VAs by the presence of MVP, and (3) LV papillary muscle VAs in the setting of cardiomyopathy. Results: Nine of 23 (39%) patients undergoing ablation of LV papillary muscle VAs had MVP compared to none of 129 (0%) patients at other sites (P < 0.001). In the former group, acute procedural success was achieved in 60% and 80% of those with and without MVP, respectively (P = 0.28). Medium‐term outcomes were comparable (P = 0.75). In patients with cardiomyopathy, the median LV ejection fraction improved from 40% to 54% following ablation (P = 0.007). Conclusions: Although MVP is strongly associated with LV papillary muscle VAs, MVP does not adversely affect the acute or medium‐term outcomes of ablation. Systolic function can improve following ablation in patients with ectopy‐mediated cardiomyopathy due to papillary muscle VAs. [ABSTRACT FROM AUTHOR]

Patients with Brugada syndrome are at risk of life-threatening ventricular arrhythmias. Epicardial substrate ablation for Brugada syndrome has been described as a means of controlling these arrhythmias and recent reports describe elimination of the Brugada phenotype with ablation. We describe a unique case in which a patient developed inferior J waves with an early repolarization-type electrocardiogram following successful epicardial infundibular substrate ablation (which eliminated the Brugada syndrome electrocardiogram on ajmaline challenge). We discuss the likely underlying pathophysiology responsible for this phenomenon, its relationship to the anatomic obstacles encountered during epicardial ablation, and the implications for long-term arrhythmic risk. [ABSTRACT FROM AUTHOR]

Green synthesized nanoparticles have gained great attention due to their non-toxic and non-hazardous nature. In the present study, bark extract of the medicinal plant in Ayurveda Crataeva nurvala (Buch-Ham) (CN) was chosen for the biosynthesis of silver nanoparticles (AgNPs). These NPs were characterized by Ultra violet visible spectroscopy, Fourier Transform Infra Red, Atomic Force Microscopy, and Transmission Electron Microscopy (TEM). The average particle size of green synthesized CN-AgNPs was 15.2 ± 1.01 nm. Gas chromatography- mass spectrometry analysis of methanolic bark extract involved in the formation of CN-AgNPs revealed lupeol as a major active component. In this study, CN-AgNPs (15 μg ml−1) efficiently suppressed the production of quorum sensing mediated virulence factors viz. pyocyanin, protease, hemolysin, and biofilm formation in Pseudomonas aeruginosa. The pyocyanin production was strongly inhibited (74.64%) followed by proteolysis (47.3%) and hemolysin production (47.7%). However, the biofilm forming ability was maximally reduced up to 79.70%. Moreover, the Confocal Laser Scanning Microscopic Analysis showed that CN-AgNPs inhibit colonization of P. aeruginosa on to the surface. Furthermore, TEM analysis revealed internalization of CN-AgNPs inside the bacterial cell. It is concluded that green synthesized AgNPs have great potential to inhibit virulence factors and biofilm forming ability of drug-resistant clinical isolates of P. aeruginosa. [ABSTRACT FROM AUTHOR]

ABSTRACT Four-week-old mice, weighing about 25-35 g were divided into five groups (8 mice in each group): vehicle control, low- (0.5 g/kg), middle- (1 g/kg), high- (3 g/kg), and exceptionally high-dose (5 g/kg). After first and second weeks of intraperitoneal exposure to AgNPs, biochemical, histopathological, and electron microscopic ultrastructural changes were investigated. No significant changes were observed in SGOT and ALP levels after first week of exposure, while the level of SGPT significantly increased ( p < 0.05) in 2nd week treated mice, indicating that inflammatory of liver might be induced by high-dose (3 and 5 g/kg) of AgNPs. No obvious changes were observed for UA and BUN in all groups of treated mice. However, significant ( p < 0.05) decrease in CR level was noticed in all groups of treated mice only at high-dose (3 and 5 g/kg). No remarkable changes in lipid profile were observed. Light microscopic histopathological investigation shows that first week treatment had not perceptible effect on the cytoarchitecture on liver, kidney, and spleen; while, second week treatment had only sporadic mild effects on these organs. However, no ultrastructural electron microscopic changes were observed in liver, kidney, and spleen of mice treated with 0.5, 1, and 3 g/kg of AgNPs when sacrificed on first and second week; while, exceptionally high-dose (5 g/kg) of AgNPs resulted in slight nuclear chromatin condensation and irregularities in nuclear membrane. The results suggested that AgNPs could be well tolerated in mice when given intraperitoneally and no death has been found during the experiment in any groups of treated mice. Interestingly, significant (<0.05) decrease in glucose levels in all experiment group is suggestive of curious hypoglycemic role of AgNPs warranting further study to explore its possible therapeutic potential in hyperglycemic conditions as well as its mechanism of action at molecular level. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 945-956, 2016. [ABSTRACT FROM AUTHOR]

In this paper, a distributed estimation algorithm using Bayesian‐based forward backward Kalman filter (KF) is proposed for stochastic singular linear systems. The method incorporates generalised versions of KF for bounded cases with complete and incomplete prior information, followed by estimation fusion of these cases. The incorporated filters remain optimal given the cross‐covariance of the local estimates. The proposed approach is validated on a coupled‐tank system. [ABSTRACT FROM AUTHOR]

In this study, an improved distributed estimation scheme for static sensor networks is developed. The scheme is developed for environmental time‐variant physical variables. The main contribution of this work is that the algorithm in Saber and Murray (2005), Carli et al. (2009) and Xiao et al. (2004) has been extended, and a filter has been designed with weights, such that the variance of the estimation errors is minimised, thereby improving the filter design considerably and characterising the performance limit of the filter, and thereby tracking a time‐varying signal. Moreover, certain parameter optimisation is alleviated with the application of a particular finite impulse response filter. Simulation results are showing the effectiveness of the developed estimation algorithm. [ABSTRACT FROM AUTHOR]

Background Triggers from thoracic veins have been implicated not only in the initiation, but also in the perpetuation of paroxysmal atrial fibrillation (PAF). To investigate their role we studied the distribution and stability of dominant frequencies (DFs) during PAF and the response to isolation of the triggering pulmonary vein (PV). Methods and Results Triggering structures inducing PAF were identified during isoproterenol challenge in 26 patients (15 males, 55 ± 8.5 years). During sustained PAF, sequential recordings were made with a decapolar circular mapping catheter from each PV and the left atrial posterior wall (LAPW), together with coronary sinus (CS) and right atrium (RA) recordings. DF was determined using fast Fourier transformation. Recordings were repeated after ≥15 minutes of PAF. Radiofrequency ablation was directed first at the triggering PVs. PAF initiated from the PVs in 24 patients and from RA in two. There was a significant frequency gradient from the triggering structure to the PVs, CS, LAPW, and RA (P < 0.0001). During the second recording, DF decreased at all sites (P < 0.02), but the frequency gradient remained unchanged. Despite isolation of the triggering PV, PAF continued in 53% of patients, although DF measured in the CS was lower. AF termination occurred with contralateral PV isolation in half of the remaining patients and further AF slowing was noted in the rest. Conclusions Triggering structures harbor the fastest activity during sustained PAF pointing to their leading role in arrhythmia perpetuation. However, nontriggering PVs also seem to contribute to PAF maintenance. [ABSTRACT FROM AUTHOR]

In recent years, a compelling need has arisen to understand the effects of distributed information structures on estimation and filtering. In this study, a bibliographical review on distributed Kalman filtering (DKF) is provided. The study contains a classification of different approaches and methods involved to DKF. The applications of DKF are also discussed and explained separately. A comparison of different approaches is briefly carried out. Focuses on the contemporary research are also addressed with emphasis on the practical applications of the techniques. An exhaustive list of publications, linked directly or indirectly to DKF in the open literature, is compiled to provide an overall picture of different developing aspects of this area. [ABSTRACT FROM AUTHOR]

Safety and Efficacy of Repeat Epicardial Access. Introduction: Epicardial mapping and ablation of ventricular tachycardia (VT) has been increasingly performed. Occasionally additional ablation is necessary, requiring repeat percutaneous access to the pericardial space. Methods and Results: We studied 30 consecutive patients who required a repeat epicardial procedure. We specifically examined the success and safety of repeat percutaneous pericardial access as well as the ability to map and ablate epicardial VT targets. Percutaneous pericardial access at a median of 110 days after the last procedure was successful in all 30 patients. Significant adhesions interfering with catheter mapping were encountered in 7 patients (23%); 6 had received intrapericardial triamcinolone acetate (IPTA) with prior procedures. Using blunt dissection with a deflected ablation catheter and a steerable sheath, adhesions were divided allowing for complete catheter mapping in 5 patients with areas of dense adherence compartmentalizing the pericardium in 1 patient and precluding ablation over previously targeted ablation site in the second. Targeted VT noninducibility was achieved in 27 (90%) patients including 7 patients with adhesions. No direct complications related to pericardial access or adhesions disruption occurred. One periprocedural death occurred from refractory cardiogenic shock in patient with LV ejection fraction of 10%. Another patient developed asymptomatic positive Haemophilus influenzae pericardial fluid cultures identified at second procedure, which was successfully treated. Conclusions: Repeat access can be obtained after prior epicardial ablation. Adhesions from prior procedures may limit mapping, but can usually be disrupted mechanically and allow for ablation of recurrent VT. IPTA may not completely prevent adhesions. (J Cardiovasc Electrophysiol, Vol. 23, pp. 744-749, July 2012) [ABSTRACT FROM AUTHOR]

Chloroquine (CQ) has been the mainstay of treatment of malaria for decades. This cost-effective and safe drug has become ineffective for treatment of falciparum malaria in many parts of the world due to development of resistance by the parasite. In addition CQ is not gametocytocidal for P. falciparum and thus cannot block transmission. The extent of problem of chloroquine resistance in P. falciparum is increasing every year. The study was done in period of 2 years. A total of 5653 specimens were examined for malarial infection by employing different diagnostic modalities. Four hundred and thirty-five were found to be positive for P. falciparum by using different diagnostic techniques. All positive specimens were cultured on RPMI 1640 medium; only 108 were found to be culture positive. Sensitivity of isolates to chloroquine was done using Mark III WHO sensitivity plates. The prevalence of malaria infection was found 9.54% in 2010. There were schizont formation at 8 pmol/liter or more of chloroquine concentration in 26 isolates. The emergence of chloroquine (CQ) resistance pattern in Aligarh isolates increases. Antimalarial agents should be used with caution; monotherapies should be avoided. [ABSTRACT FROM AUTHOR]

Ablation of Right Atrial Free Wall Flutter. Introduction: Ablation for atypical atrial flutter (AFL) is often performed during tachycardia, with termination or noninducibility of AFL as the endpoint. Termination alone is, however, an inadequate endpoint for typical AFL ablation, where incomplete isthmus block leads to high recurrence rates. We assessed conduction block across a low lateral right atrial (RA) ablation line (LRA) from free wall scar to the inferior vena cava (IVC) or tricuspid annulus in 11 consecutive patients with atypical RA free wall flutter. Method and results: LRA block was assessed following termination of AFL, by pacing from the ablation catheter in the low lateral RA posterior to the ablation line and recording the sequence and timing of activation anterior to the line with a duodecapole catheter, and vice versa for bidirectional block. LRA block resulted in a high to low activation pattern on the halo and a mean conduction time of 201 ± 48 ms to distal halo. LRA conduction block was present in only 2 out of 6 patients after termination of AFL by ablation. Ablation was performed during sinus rhythm (SR) in 9 patients to achieve LRA conduction block. No recurrence of AFL was observed at long-term follow-up (22 ± 12 months); 3 patients developed AF. Conclusion: Termination of right free wall flutter is often associated with persistent LRA conduction and additional radiofrequency ablation (RFA) in SR is usually required. Low RA pacing may be used to assess LRA conduction block and offers a robust endpoint for atypical RA free wall flutter ablation, which results in a high long-term cure rate. (J Cardiovasc Electrophysiol, Vol. 21, pp. 526-531, May 2010) [ABSTRACT FROM AUTHOR]

The prognostic benefit of the implantable cardioverter-defibrillator (ICD) has been well established in multiple settings and its use is consequently widespread. Modern-day ICD systems use transvenous high-voltage leads to act as the interface between the heart and the generator, allowing for the sensing of a cardiac activity and the delivery of both bradycardia and tachycardia therapy, including high-voltage, high-current shocks. The ICD lead is in many ways the most fragile and critical component of the ICD system, and is subjected to more stress than any other implanted medical device. It has similar components to a pacing lead including tip and ring electrodes, fixation mechanism, conductors, insulators, and connector pins. In addition, it also contains the high-voltage shock coils that allow the delivery of defibrillation therapy to the cardiac tissue. The materials used to manufacture each of these components have undergone little evolution from their initial pacing lead-derived origin, but promising progress in this area is now occurring and better conductors and insulators have been developed. Lead body design continues to be multiluminal rather than coaxial, but various iterations of this basic paradigm continue to be investigated. In addition to miniaturization of the entire ICD lead, new industry standard lead connectors will also be introduced to reduce complexity and pocket bulk. However, long-term failure rates have been considerable, with lead failure related to both conductor and insulator malfunction. It is hoped that recent improvements in an ICD lead design and manufacture will result in a good functionality with a reliable long-term performance. [ABSTRACT FROM AUTHOR]

Monomorphic ventricular tachycardia (VT) can arise from multiple different ventricular locations in the context of several different underlying myocardial substrates. Despite this variability, the surface 12-lead electrocardiograph (ECG) has proven to be a robust and reproducible initial mapping tool that can provide useful information in localizing the origin of both focal and reentrant forms of VT. The second part of this review series will look at the use of the ECG in mapping the various forms of VT encountered in clinical practice. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the T1rho (T(1rho)) MRI relaxation time in hippocampus in the brain of Alzheimer's disease (AD), mild cognitive impairment (MCI), and control, and to determine whether the T(1rho) shows any significant difference between these cohorts.Materials and Methods: With informed consent, AD (n = 49), MCI (n = 48), and age-matched control (n = 31) underwent T(1rho) MRI on a Siemens 1.5T Scanner. T(1rho) values were automatically calculated from the left and right hippocampus region using in-house developed software. Bonferroni post-hoc multiple comparisons was performed to compare the T(1rho) value among the different cohorts.Results: Significantly higher T(1rho) values were observed both in AD (P = 0.000) and MCI (P = 0.037) cohorts compared to control; also, the T(1rho) in AD was significantly high over (P = 0.032) MCI. Hippocampus T(1rho) was 13% greater in the AD patients than control, while in MCI it was 7% greater than control. Hippocampus T(1rho) in AD patients was 6% greater than MCI.Conclusion: Higher hippocampus T(1rho) values in the AD patients might be associated with the increased plaques burden. A follow-up study would help to determine the efficacy of T(1rho) values as a predictor of developing AD in the control and MCI individuals. [ABSTRACT FROM AUTHOR]

Objective: To characterize the electrocardiographic and electrophysiological features and frequency of focal atrial tachycardia (AT) originating from the right atrial appendage (RAA). Background: The RAA has been described as a site of origin of AT, but detailed characterization of these tachycardias is limited. Methods: Ten patients (3.8%) of 261 undergoing radiofrequency ablation (RFA) for focal AT are reported. Endocardial activation maps (EAM) were recorded from catheters at the CS (10 pole), tricuspid annulus (20 pole Halo catheter), and His positions. P waves were classified as negative, positive, isoelectric, or biphasic. Results: The mean age was 39 ± 20 years, nine males, with symptoms for 4.1 ± 5.1 years. Tachycardia was incessant in seven patients, spontaneous in one patient, and induced by programmed extrastimuli in two patients. These foci had a characteristic P wave morphology. The P wave was negative in lead V1 in all patients, becoming progressively positive across the precordial leads. The P waves in the inferior leads were low amplitude positive in the majority of patients. Earliest EAM activity occurred on the Halo catheter in all patients. Mean activation time at the successful RFA site =−38 ± 15 msec. Irrigated catheters were used in six patients, due to difficulty achieving adequate power. RFA was acutely successful in all patients. Long-term success was achieved in all patients over a mean follow up of 8 ± 7 months. Conclusions: The RAA is an uncommon site of origin for focal AT (3.8%). It can be suspected as a potential anatomic site of AT origin from the characteristic P wave and activation timing. Irrigated ablation catheters are often required for successful ablation. Long-term success was achieved with focal ablation in all patients. [ABSTRACT FROM AUTHOR]

The authors reflect on the use of ventricular tachycardia substrate mapping in catheter ablation for scar-related ventricular tachycardia (VT). In the article the authors discuss research which has investigated ablation and mapping and offer their opinions on several points raised in the article "Integration of Merged Delayed-Enhanced Magnetic Resonance Imaging and Multi-Detector Computed Tomography for the Guidance of Ventricular Tachycardia Ablation:A Pilot Study" by H. Cochet et al.

An editorial is presented which discusses the role of radiofrequency (RF) in interventional cardiac electrophysiology. The author describes RF catheter ablation for the treatment of atrial fibrillation (AF) and the role that electrode-tissue coupling plays in determining the size of myocardial tissue lesions and the safety and efficacy of catheter ablation.

The author discusses the evolution of catheter ablation (CA) for atrial fibrillation (AF). According to the author, the approach involved a laborious process of AF induction given an attempt to identify the responsible site within the pulmonary veins. The author noted that the difficulties in mapping AF triggers a significant incidence of pulmonary vein stenosis associated with radiofrequency applications within the veins.

This article presents a study regarding a 45-year-old man with multifocal cystic dilation of the intrahepatic bile ducts and medullary sponge kidneys. The patient was diagnosed with Caroli's syndrome, a rare congenital disorder characterized by multifocal, saccular or cystic dilations of the intrahepatic bile ducts.

The author talks about implantable cardioverter-defibrillator (ICD) therapy in Australia and its epidemiology and costs, discussing the prevention of sudden cardiac death using ICD, the evidence of ICD's effectiveness in secondary prevention patients, and its increased use in primary prevention.

Background: The need of an early and noninvasive diagnosis of AD requires the development of imaging-based techniques. As an alternative, the magnetic resonance image (MRI) relaxation time constant (T1ρ) was measured in brains of Alzheimer's disease (AD), mild-cognitive impairment (MCI), and age-matched controls in order to determine whether T1ρ values correlated with the neurological diagnosis.Methods: MRI was performed on AD (n=48), MCI (n=45), and age-matched control (n=41), on a 1.5 Tesla Siemens clinical MRI scanner. T1ρ maps were generated by fitting each pixel's intensity as a function of the duration of the spin-lock pulse. T1ρ values were calculated from the gray matter (GM) and white matter (WM) of medial temporal lobe (MTL).Results: GM and WM T1ρ values were 87.5±1.2 ms and 80.5±1.4 ms, respectively, in controls, 90.9±1.3 ms and 84.1±1.7 ms in MCI, and 91.9±.8 ms and 88.3±1.3 ms in AD cohorts. Compared to control, AD patients showed 9% increased WM T1ρ and 5% increased GM T1ρ. Compared to control, MCI individuals showed 4% increased T1ρ both in WM and GM. A 5% increased T1ρ was found in WM of AD over MCI.Conclusion: The increased T1ρ in WM and GM of MTL in AD may be associated with the pathological changes that are not evident on conventional MRI. [ABSTRACT FROM AUTHOR]

Background Leadless pacemaker is a novel technology, and evidence supporting its use is uncertain. We performed a systematic review and meta-analysis to examine the safety and efficacy of leadless pacemakers implanted in the right ventricle. Methods and Results We searched PubMed and Embase for studies published before June 6, 2020. The primary safety outcome was major complications, whereas the primary efficacy end point was acceptable pacing capture threshold (≤2 V). Pooled estimates were calculated using the Freedman-Tukey double arcsine transformation. Of 1281 records screened, we identified 36 observational studies of Nanostim and Micra leadless pacemakers, with most (69.4%) reporting outcomes for the Micra. For Micra, the pooled incidence of complications at 90 days (n=1608) was 0.46% (95% CI, 0.08%-1.05%) and at 1 year (n=3194) was 1.77% (95% CI, 0.76%-3.07%). In 5 studies with up to 1-year follow-up, Micra was associated with 51% lower odds of complications compared with transvenous pacemakers (3.30% versus 7.43%; odds ratio [OR], 0.49; 95% CI, 0.34-0.70). At 1 year, 98.96% (95% CI, 97.26%-99.94%) of 1376 patients implanted with Micra had good pacing capture thresholds. For Nanostim, the reported complication incidence ranged from 6.06% to 23.54% at 90 days and 5.33% to 6.67% at 1 year, with 90% to 100% having good pacing capture thresholds at 1 year (pooled result not estimated because of the low number of studies). Conclusions Most studies report outcomes for the Micra, which is associated with a low risk of complications and good electrical performance up to 1-year after implantation. Further data from randomized controlled trials are needed to support the widespread adoption of these devices in clinical practice.