Crop productivity estimation by integrating multisensor satellite, in situ, and eddy covariance data into efficiency-based model.

Accurate and quantitative regional estimates of the carbon budget require an integration of eddy covariance (EC) flux-tower observations and remote sensing in ecosystem models. In this study, a simple remote sensing driven light use efficiency (LUE) model was used to estimate the primary productivity for major cropping systems using multi-temporal satellite data over the Saharanpur district in India.The model is based on radiation absorption and its conversion into biomass. The LUE model was implemented for major crop rotations derived from the time-series of Sentinel-2 and Landsat 8 with monthly satellite-based spatially explicit fields of photosynthetically active radiation (PAR), fraction of absorbed PAR (fAPAR) and down-regulated light use efficiency. Incident PAR and fAPAR were estimated on monthly basis from the ground-calibrated empirical equation using INSAT-3D insolation product and remote sensing-based vegetation indices, respectively. Spatial LUE maps created by down-regulating maximum LUE (EC tower-based) with water and temperature stressors derived from land surface water index (LSWI) and EC-based cardinal temperature, respectively. LUE-based modeled GPP over the sugarcane-wheat system was found higher than the rice-wheat system in Saharanpur district. This is because C4 crop (sugarcane) has very high photosynthetic efficiency compared to C3 crops (rice and wheat). Modeled GPP over the sugarcane-wheat system was found in good agreement with observed EC tower-based GPP (Index of Agreement = 0.93). Further regionally calibrated remote sensing-based LUE model well captures gross photosynthesis rates (GPP) over cropland ecosystem compared to globally modeled MODIS GPP product.

Corrigendum to "Detailed urban roughness parametrization for anthropogenic heat flux estimation using earth observation data" [Heliyon 9(7) (July 2023) e18361].

[This corrects the article DOI: 10.1016/j.heliyon.2023.e18361.].

Detailed urban roughness parametrization for anthropogenic heat flux estimation using earth observation data.

Anthropogenic Heat (AH) emissions modify the energy balance in urban areas and is crucial for urban microclimate modelling and improved weather forecast modelling. Therefore, the present study conducted on Delhi and its surroundings firstly aims to estimate AH using Earth Observation (EO) data of Landsat 8 then, evaluate the impact of detailed urban roughness parameterization on the estimation of AH and further validate the obtained flux values with ground based observations of Large Aperture Scintillometer (LAS) setup. The study has been conducted over three time periods for October 2017, March 2018 and June 2018 by processing six Landsat tiles. Three methods have been employed on EO data for AH computation i.e. single urban roughness value for entire study area (Method 1), LULC based roughness values adopted from the literature (Method 2) and lastly, detailed pixel-by-pixel varying roughness values calculated from fine scale urban parameterization (Method 3) for each time period, The average AH values are higher for the month of June 2018: 359.91, 368.57 and 359.16 W/m2 as compared to month of March 2018 (322.44, 330.84 and 298.35 W/m2) and October 2017 (318.00, 331.04 and 306.71 W/m2) for method 1, method 2 and method 3 respectively. Net radiation and Sensible Heat Flux shows a good correspondence with in-situ measurements for most of the tiles and method 3 shows better spatial distribution of fluxes as compared to other two methods. However, due to difference in approach for estimation of fluxes (LAS setup computes latent heat flux as residual while EO based approach computes AH as residual), conclusive results could not be drawn with respect to aptness of a single method. Accurate estimation of AH in urban areas can assist further in formulating policies, regulations and action plans related to mitigation and control of heat stress, climate change and improved weather forecasting.

Integrated use of regional weather forecasting and crop modeling for water stress assessment on rice yield.

This study evaluated the effects of water stress on rice yield over Punjab and Haryana across North India by integrating Weather Research Forecasting (WRF) and Decision Support System for Agrotechnology Transfer (DSSAT) models. Indian Remote Sensing Satellite datasets were used to define land use/land cover in WRF. The accuracy of simulated rainfall and temperature over Punjab and Haryana was evaluated against Tropical Rainfall Measuring Mission and automated weather station data of Indian Space Research Organization, respectively. Data from WRF was used as weather input to DSSAT to simulate rice yield in Punjab and Haryana for 2009 and 2014. After simulated yield has been evaluated against district-level observed yield, the water balance components within the DSSAT model were used to analyze the impact of water stress on rice yield. The correlation (R2) between the crop water stress factor and the rice yield anomaly at the vegetative and reproductive stage was 0.64 and 0.52 for Haryana and 0.73 and 0.68 for Punjab, respectively. Severe water stress during the flowering to maturity stage inflicted devastating effects on yield. The study concludes that the regional climate simulations can be potentially used for early water stress prediction and its impact on rice yield.

Hemato-biochemical and ultrasonographic evaluation of hepatic lipidosis in dairy buffaloes.

Around 60% dairy animals developed moderate to severe hepatic lipidosis at the time of parturition or during early lactation stage. Most of clinician suspect the hepatic lipidosis during above time window only. However, negative energy balance or feeding of high concentrate diet can lead to hepatic lipidosis at any phase of life. The aim of the present study was to evaluate the potential for diagnosis of hepatic lipidosis by means of hemato-biochemical parameters and ultrasonography of the liver at any stage of life. Here, ultrasonographic back fat thickness measurement was correlated with ultrasonographic features of hepatic lipidosis. A total 60 buffaloes were included under the study and sampled for hematological and biochemical parameters. Hematological parameters did not exhibit any significant difference between healthy and hepatic lipidosis-affected buffaloes. Biochemical parameters like beta hydroxy butyric acid, non esterified fatty acid, aspartate amino transferase, gamma glutamyl transferase and alkaline phosphatase revealed a significant increase, while triglyceride, cholesterol, and glucose declined significantly in hepatic lipidosis-affected buffaloes. Total protein, albumin, and total bilirubin levels did not exhibit any significant difference. Based on ultrasonographic findings, the hepatic lipidosis-affected buffaloes were further sub divided into mild, moderate, and severe groups. Portal vein diameter and depth of portal vein were also estimated in current study. Ultrasonographic examination could diagnose 53.33% hepatic lipidosis cases in buffaloes. Among it, 37.50% buffalo had mild hepatic lipidosis, 33.33% had moderate hepatic lipidosis, and 29.16% had severe hepatic lipidosis. Depth of portal vein significantly increased in hepatic lipidosis cases. However, portal vein diameter exhibited a non-significant difference in mild, moderate, and severe groups of hepatic lipidosis. Back fat thickness also revealed a non-significant difference in mild, moderate, and severe hepatic lipidosis. Above study indicate that B mode ultrasonography of the liver can be employed to differentiate various grades of hepatic lipidosis in buffaloes. Biochemical parameters like NEFA, BHBA, AST, GGT, ALP, TG, cholesterol, and glucose can be helpful to screen the hepatic lipidosis at farm level.

Dynamics of CO2 fluxes and controlling environmental factors in sugarcane (C4)-wheat (C3) ecosystem of dry sub-humid region in India.

In this study, CO2 exchange over sugarcane and wheat growing season was quantified by continuous measurement of CO2 fluxes using eddy covariance (EC) system from January 2014 to June 2015. We also elaborated on the response of CO2 fluxes to environmental variables. The results show that the ecosystem has seasonal and diurnal dynamics of CO2 with a distinctive U-shaped curve in both growing seasons with maximal CO2 absorption reaching up to -8.94 g C m-2 day-1 and -6.08 g C m-2 day-1 over sugarcane and wheat crop, respectively. The ecosystem as a whole acted as a carbon sink during the active growing season while it exhibits a carbon source prior to sowing and post-harvesting of crops. The cumulative net ecosystem exchange (NEE), gross primary productivity (GPP), and ecosystem respiration (Reco) were -923.04, 3316.65, and 2433.18 g C m-2 over the sugarcane growing season while the values were -192.30, 621.47, and 488.34 g C m-2 over the wheat growing season. The sesbania (green manure) appeared to be a carbon source once it is incorporated into soil. The response of day-time NEE to photosynthetically active radiation (PAR) under two vapor pressure deficit (VPD) sections (0-20 h Pa and 20-40 h Pa) seems more effective over sugarcane (R2 = 0.41-0.61) as compared to the wheat crop (R2 = 0.25-0.40). A decrease in net CO2 uptake was observed under higher VPD conditions. Similarly, night-time NEE was exponentially related to temperature at different soil moisture conditions and showed higher response to optimum soil moisture conditions for sugarcane (R2 = 0.87, 0.33 ≤ SWC < 0.42 m3 m-3) and wheat (R2 = 0.75, 0.31 ≤ SWC < 0.37 m3 m-3) crop seasons. The response of daily averaged NEE to environmental variables through path analysis indicates that PAR was the dominant predictor with the direct path coefficient of -0.65 and -0.74 over sugarcane and wheat growing season, respectively. Satellite-based GPP products from Moderate Resolution Imaging Spectroradiometer (GPPMOD) and Vegetation Photosynthetic model (GPPVPM) were also compared with the GPP obtained from EC (GPPEC) technique. The seasonal dynamics of GPPEC and GPPVPM agreed well with each other. This study covers the broad aspects ranging from micro-meteorology to remote sensing over C4-C3 cropping system.

Physiologic load-bearing characteristics of autografts, allografts, and polymer-based scaffolds in a critical sized segmental defect of long bone: an experimental study.

BACKGROUND: To address the challenge of treating critical sized intercalary defects, we hypothesized that under physiologic cyclic loading, autografts, allografts, and scaffolds loaded with and without human mesenchymal stem cells (hMSCs) would have different biomechanical characteristics. METHODS: Using a rat femoral defect model, 46 rats were assigned to four groups, ie, autograft (n = 12), allograft (n = 10), scaffold (n = 13), and scaffold with hMSCs (n = 11). The scaffold groups used a 5 mm segment of scaffold composed of 80% poly-ε-caprolactone and 20% hydroxyapatite. Rats were sacrificed 4 months postoperatively, and the repairs were assessed radiographically and biomechanically. RESULTS: Autograft and allograft groups exhibited the most bridging callus, while the scaffold/hMSCs group had more callus than the scaffold repairs. Although signs of radiographic healing did not accurately reflect restoration of mechanical properties, addition of hMSCs on the scaffold enhanced bone formation. The scaffold alone group had significantly lower elastic and viscous stiffness and higher phase angles than other repairs and the contralateral controls. Addition of hMSCs increased the elastic and viscous stiffness of the repair, while decreasing the phase angle. CONCLUSION: Further comparative analysis is needed to optimize clinical use of scaffolds and hMSCs for critical sized defect repairs. However, our results suggest that addition of hMSCs to scaffolds enhances mechanical simulation of native host bone.

Development and validation of packed column supercritical fluid chromatographic technique for quantification of chlorzoxazone, paracetamol and aceclofenac in their individual and combined dosage forms.

A reproducible, rapid and sensitive method has been developed for the assay of chlorzoxazone (CHL), paracetamol (PCM) and aceclofenac (ACE) in their combined solid dosage forms using packed-column supercritical fluid chromatography (SFC). The analytes were resolved by elution with supercritical carbon dioxide doped with 15% v/v methanol as the modifier on an ACE 5 Phenyl column (150 × 4.6 mm, 5 µm). The detection was carried out at 215 nm using a UV-Visible detector. The densities and polarities of the mobile phase were optimized from the effects of pressure, temperature and modifier concentration on chromatographic parameters like retention time, retention factor, resolution, asymmetry and theoretical plates. Modifier concentration proved to be the most effective means for changing both retention and selectivity. The developed method was validated as per International Conference on Harmonization guidelines. The developed SFC method was compared with a reported high-performance liquid chromatography method for the estimation of CHL, PCM and ACE using Student t-test. With respect to the speed and use of organic solvents, SFC was found to be superior and eco-friendly. The developed SFC method was successfully used for the assay of different marketed formulations containing CHL, PCM and ACE individually and in combination.

Allergic mastocytic gastroenteritis and colitis: an unexplained etiology in chronic abdominal pain and gastrointestinal dysmotility.

Abdominal pain, bloating, early satiety, and changes in bowel habits are common presenting symptoms in individuals with functional GI disorders. Emerging data suggests that these symptoms may be associated with mast cell excess and/or mast cell instability in the GI tract. The aim of this retrospective study was to evaluate the contribution of mast cells to the aforementioned symptoms in individuals with a history of atopic disease. A retrospective chart review of individuals seen in a university GI practice was conducted and twenty-four subjects were identified. The majority had abdominal pain, early satiety, and nocturnal awakening. 66.7% and 37.5% had a history of environmental and/or food allergy. Solid gastric emptying was increased as were the mean number of mast cells reported on biopsies from the stomach, small bowel, and colon (>37/hpf) by CD117 staining. Mean whole blood histamine levels were uniformly elevated. This study suggests that in individuals with these characteristics, consideration should be given to staining their gastrointestinal biopsies for mast cells as this may provide them with relatively non-toxic but highly targeted treatment options. Allergic gastroenteritis and colitis may represent a third type of GI mast cell disorder along with mast cell activation syndrome and mastocytic enterocolitis.

Analysis of agricultural drought using vegetation temperature condition index (VTCI) from Terra/MODIS satellite data.

The most commonly used normalized difference vegetation index (NDVI) from remote sensing often fall short in real-time drought monitoring due to a lagged vegetation response to drought. Therefore, research recently emphasized on the use of combination of surface temperature and NDVI which provides vegetation and moisture conditions simultaneously. Since drought stress effects on agriculture are closely linked to actual evapotranspiration, we used a vegetation temperature condition index (VTCI) which is more closely related to crop water status and holds a key place in real-time drought monitoring and assessment. In this study, NDVI and land surface temperature (T (s)) from MODIS 8-day composite data during cloud-free period (September-October) were adopted to construct an NDVI-T (s) space, from which the VTCI was computed. The crop moisture index (based on estimates of potential evapotranspiration and soil moisture depletion) was calculated to represent soil moisture stress on weekly basis for 20 weather monitoring stations. Correlation and regression analysis were attempted to relate VTCI with crop moisture status and crop performance. VTCI was found to accurately access the degree and spatial extent of drought stress in all years (2000, 2002, and 2004). The temporal variation of VTCI also provides drought pattern changes over space and time. Results showed significant and positive relations between CMI (crop moisture index) and VTCI observed particularly during prominent drought periods which proved VTCI as an ideal index to monitor terminal drought at regional scale. VTCI had significant positive relationship with yield but weakly related to crop anomalies. Duration of terminal drought stress derived from VTCI has a significant negative relationship with yields of major grain and oilseeds crops, particularly, groundnut.

It's good to talk! Changes in coronary revascularisation practice in PCI centres without onsite surgical cover and the impact of an angiography video conferencing system.

INTRODUCTION: Percutaneous coronary intervention (PCI) activity has increased more than 6 fold in the last 15 years. Increased demand has been met by PCI centres without on-site surgical facilities. To improve communication between cardiologists and surgeons at a remote centre, we have developed a video conferencing system using standard internet links. The effect of this video data link (VDL) on referral pattern and patient selection for revascularisation was assessed prospectively after introduction of a joint cardiology conference (JCC) using the system. METHODS: Between 1st October 2005 and 31st March 2007, 1346 patients underwent diagnostic coronary angiography (CA). Of these, 114 patients were discussed at a cardiology conference (CC) attended by three consultant cardiologists (pre-VDL). In April 2007, the VDL system was introduced. Between 1st April 2007 and 30th September 2008, 1428 patients underwent diagnostic CA. Of these, 120 patients were discussed at a JCC attended by four consultant cardiologists and two consultant cardiothoracic surgeons (post-VDL). Following case-matching for patient demographics and coronary artery disease (CAD) severity and distribution, we assessed the effect upon management decisions arising from both the pre- and post-VDL JCC meetings. RESULTS: When comparing decision-making outcomes of post-VDL JCC with pre-VDL CC, significantly fewer patients were recommended for PCI (36.8% vs. 17.2% respectively, p = 0.001) and significantly more patients were recommended for surgery (21.1% vs. 48.4% respectively, p < 0.001). There were no significant differences in waiting times for PCI following JCC discussion; however, waiting times for surgical revascularisation were significantly reduced (140.9 ± 71.8 days vs. 99.4 ± 56.6 days respectively, p = 0.045). CONCLUSIONS: The VDL system provides a highly practical method for PCI centres without onsite surgical cover to discuss complex patients requiring coronary revascularisation and significantly increases the number of patients referred for surgical revascularisation rather than PCI.

First time and repeat cardioversion of atrial tachyarrhythmias - a comparison of outcomes.

INTRODUCTION: Repeat cardioversion may be necessary in over 50% of patients with persistent atrial fibrillation (AF), but identifying responders remains challenging. This study evaluates the long-term success of direct current cardioversion (DCCV) and the clinical and echocardiographical parameters that influence them, in over 1000 sedation-cardioversion procedures undertaken at Eastbourne General Hospital between 1996 and 2006. METHODS: A total of 770 patients of mean age (SD) 70.1(10.1) underwent 1013 DCCVs (first n = 665, repeat n = 348) for atrial tachyarrhythmias from 1996 to 2006. Time to persistent arrhythmia recurrence was compared between first and multiple DCCV, and the effect of age, gender, presence of heart disease, left atrial size, fractional shortening, arrhythmia duration, anti-arrhythmic drug therapy (AAD) and other concomitant cardiac medication was evaluated using the Kaplan-Meier method and Cox's Proportional-hazards model. RESULTS: In all, 33% of first and 29% of repeat DCCVs were in sinus rhythm (SR) at 12 months (m). There was no difference in median time to arrhythmia recurrence (SE) between first and multiple procedures: 1.5 +/- 0.1 m (1.3-1.7) and 1.5 +/- 0.0 m (1.4-1.6) respectively, p = 0.45. AAD use was significantly higher, arrhythmia duration shorter and more diabetic patients underwent repeat procedures. Amiodarone, OR 0.56, p = 0.04, sotalol, OR 0.61, p = 0.02 and arrhythmia duration, < 6 m, OR 0.72, p = 0.03 were independent predictors of improved outcome in first procedures only. In patients undergoing first procedures on amiodarone or sotalol, median time to arrhythmia recurrence was longer and 12 m SR rates higher, 6.0 +/- 2.4 m (42%) than those who had a repeat procedure on the same medication, 1.5 +/- 0.1 m (33%), p = 0.06. CONCLUSIONS: The efficacy of first and subsequent DCCV procedures is similar, achieving a similar proportion of SR maintenance at 1 year. However, the benefits of AAD therapy are the greatest following first time procedures. Concomitant AAD therapy should be considered for all first time procedures for persistent AF.

Estimation and analysis of terrestrial net primary productivity over India by remote-sensing-driven terrestrial biosphere model.

In the present study, the Carnegie-Ames-Stanford Approach (CASA), a terrestrial biosphere model, has been used to investigate spatiotemporal pattern of net primary productivity (NPP) during 2003 over the Indian subcontinent. The model drivers at 2-min spatial resolution were derived from National Oceanic and Atmospheric Administration advanced very high resolution radiometer normalized difference vegetation index, weather inputs, and soil and land cover maps. The annual NPP was estimated to be 1.57 Pg C (at the rate of 544 g C m(-2)), of which 56% contributed by croplands (with 53% of geographic area of the country (GAC)), 18.5% by broadleaf deciduous forest (15% of GAC), 10% by broadleaf evergreen forest (5% of GAC), and 8% by mixed shrub and grassland (19% of GAC). There is very good agreement between the modeled NPP and ground-based cropland NPP estimates over the western India (R2=0.54; p=0.05). The comparison of CASA-based annual NPP estimates with the similar products from other operational algorithms such as C-fix and Moderate Resolution Imaging Spectroradiometer (MODIS) indicate that high agreement exists between the CASA and MODIS products over all land covers of the country, while agreement between CASA and C-Fix products is relatively low over the region dominated by agriculture and grassland, and the agreement is very low over the forest land. Sensitivity analysis suggest that the difference could be due to inclusion of variable light use efficiency (LUE) across different land cover types and environment stress scalars as downregulator of NPP in the present CASA model study. Sensitivity analysis further shows that the CASA model can overestimate the NPP by 50% of the national budget in absence of downregulators and underestimate the NPP by 27% of the national budget by the use of constant LUE (0.39 gC MJ(-1)) across different vegetation cover types.

A randomised controlled trial comparing StarClose and AngioSeal vascular closure devices in a district general hospital--the SCOAST study.

AIMS: AngioSeal and StarClose are vascular closure devices (VCDs) that can be used following cardiac catheterisation via the femoral artery to achieve haemostasis. Both devices have been demonstrated to be superior to conventional manual pressure, which reduce time to haemostasis and time to patient ambulation. We sought to compare these devices in a prospective, randomised trial. METHODS: Patients undergoing elective coronary angiography were randomised to receive either AngioSeal VIP or StarClose VCD with immediate postprocedure mobilisation. Bruising was recorded at 30 min, 60 min and at 1 week postprocedure. Patient satisfaction surveys were taken at 1 h and 1 week postprocedure. Complications for both groups were compared. RESULTS: Four hundred and one patients were included. Arteriotomy closure was achieved in 144 of 208 (69.2%) patients randomised to AngioSeal and 134 of 193 (69.3%) patients randomised to StarClose (p = ns). There was no significant bruising in either group at either 30 or 60 min postprocedure. However, at 1 week, there was significantly more bruising in the AngioSeal group than the StarClose group (63.1 vs. 38.5cm2, p = 0.02). Patient satisfaction and pain perception with the procedure at closure were not significantly different between the groups. Deployment success and instant mobilisation rates were significantly lower for junior, as compared with senior, operators. CONCLUSION: Achievement of haemostasis is similar with both AngioSeal and StarClose. The StarClose vascular closure device results in significantly less bruising at 1 week postprocedure as compared with AngioSeal, with no significant differences in complication rates. Patients' pain perception and satisfaction are similar with both VCDs.

Single-stage posterior transpedicular approach for circumferential epidural decompression and three-column stabilization using a titanium cage for upper thoracic spine neoplastic disease: a case series and technical note.

Two or three-column neoplastic spinal disease requiring circumferential decompression and instrumented stabilization is commonly treated through combined anterior transcavitary and posterior surgical approaches. An alternative approach advocated in the literature is costotransversectomy and interbody cage insertion. The authors present an effective and less invasive treatment paradigm using a single-stage posterior transpedicular approach (TPA) to circumferential thoracic decompression and fixation, avoiding the morbidity of thoracic or thoraco-abdominal access based on a series of eight patients with upper thoracic neoplastic disease.

A randomised controlled trial comparing the routine use of an Angio-Seal STS device strategy with conventional femoral haemostasis methods in a district general hospital.

Femoral artery closure devices reduce the time to haemostasis and ambulation. Most district general hospitals (DGHs) now perform day case angiography on site. The purpose of this study was to assess the Angio-Seal self-tightening suture (STS) device in comparison with manual compression in this environment. A prospective randomised controlled trial was undertaken comparing the Angio-Seal STS device with manual pressure recording complications, time from end of procedure and patient satisfaction in a DGH setting. Angiography lists of 206 patients undergoing day case diagnostic cardiac catheterisation with a five French sheath at a DGH were randomised by intention to treat to receive either manual compression or a six French Angio-Seal STS device. Time from sheath removal to mobilisation, complication rate and patient satisfaction were compared. There were no significant differences between the two groups in terms of demographics (manual compression: Angio-Seal; male (%) 58 vs. 57, age (years) 65.4 vs. 66.3, body mass index (kg/m(2)) 27.7 vs. 27.5). Despite randomisation, only 74 of 107 patients in the Angio-Seal group actually had a device deployed. Angio-Seal use was associated with significantly shorter times to mobilisation (87.6 vs. 144.1 min; p < 0.001), significantly less bruising (bruise size at 1 week (28.5 vs. 82.5 cm(3); p < 0.01) and no increase in vascular complications. In addition, patients were more satisfied with Angio-Seal devices in terms of length of immobility. The routine use of Angio-Seal closure devices result in earlier mobilisation, less bruising, increased patient satisfaction with no increase in other complications in comparison to manual pressure.

What is the optimal electrode configuration for atrial defibrillators in man?

AIMS: To compare the atrial defibrillation threshold (DFT) for two electrode configurations in patients with drug refractory persistent atrial fibrillation (AF). METHODS AND RESULTS: 11 patients, 73% male, mean age 60.9 (range 38 to 83), underwent implantation of a Medtronic Jewel AF dual chamber defibrillator (model 7250). A step-up atrial DFT was performed in a randomized sequence for two electrode configurations: (1) Right atrial to distal coronary sinus electrode (RA > CS) and (2) defibrillator can to right ventricular and right atrial electrodes (CAN > RV + RA). The RA > CS configuration restored SR in 10 patients (91%). The CAN > RA + RV configuration restored SR in four patients (36%). The mean atrial DFT was significantly lower for the RA > CS than CAN > RA + RV configuration (10 +/- 7 Joules vs 25 +/- 6 Joules), P < 0.01. At 3 months post implantation, AF was reinduced and the protocol was repeated for the optimal electrode configuration. There was no significant difference in the atrial DFT compared with that at implant. CONCLUSION: The right atrium to coronary sinus electrode configuration significantly reduces the atrial DFT. The atrial DFT also remains stable at 3 months post-implantation. Patients with persistent AF undergoing insertion of an atrial defibrillator should have a coronary sinus electrode implanted.

Safety, effectiveness and cost efficacy of diagnostic electrophysiology and radiofrequency ablation in a district general hospital.

Electrophysiological studies (EPS) are now being performed in district general hospitals (DGH) in the UK. In order to audit our results, a prospective database was established for all patients undergoing EPS and radiofrequency (RF) ablation at Eastbourne District General Hospital, East Sussex. Between 1 January 1997 and 1 July 2000, 300 EPS procedures were performed, resulting in 155 RF ablations. The average RF ablation procedure time was 119.3 minutes with an average fluoroscopy time of 19.1 minutes. Cost per RF ablation procedure was 1166.79 Pounds excluding use of facilities, pacemaker devices, medical nursing and radiography staffing costs. The overall success rate for RF ablation was 93.6% with a major complication rate of 0.6%, a total complication rate of 3.9% and no associated mortality. We have shown that RF ablation can be performed safely, effectively and economically in a DGH setting with a high rate of success and a low complication rate.