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Search Results: 1 - 10 of 7964 matches for " Ahmad Yaminisharif "
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Characterization of Suitability of Coronary Venous Anatomy for Targeting Left Ventricular Lead Placement in Patients Undergoing Cardiac Resynchronization Therapy
Ahmad Yaminisharif,Gholamreza Davoodi,Ali Kazemisaeid,Saeed Sadeghian
Journal of Tehran University Heart Center , 2012,
Abstract: Background: Differences in the quantity and distribution of coronary veins between patients with ischemic and non-ischemic cardiomyopathy might affect the potential for the left ventricular (LV) lead targeting in patients undergoing cardiac resynchronization therapy (CRT). In the current study, we assessed and compared the suitability of the coronary venous system for the LV lead placement in ischemic and dilated cardiomyopathy. Methods: This single-centre study, performed at our hospital, retrospectively studied 173 patients with the New York Heart Association class III or IV who underwent CRT. The study population was comprised of 74 patients with an ischemic underlying etiology and 99 patients with a non-ischemic etiology. The distribution of the veins as well as the final lead positions was recorded. Results: There was no significant difference between the two groups in terms of the position of the available suitable vein with the exception of the posterior position, where the ischemic group had slightly more suitable veins than did the dilated group (48.4% versus 32.1%, p value = 0.049). There was also no significant difference with respect to the final vein, through which the LV lead was inserted. Comparative analysis showed that the patients with previous coronary artery bypass grafting surgery (CABG) had significantly fewer suitable veins in the posterolateral position than did the non-CABG group (16.3% versus 38.7%, p value = 0.029). There was, however, no significant difference between the two subgroups regarding the final vein position in which the leads were inserted. Conclusion: The final coronary vein position suitable and selected for the LV lead insertion was not different between the cases with cardiomyopathy with different etiologies, and nor was it different between the ischemic cases with and without a history of CABG. Patients with a history of procedures around the coronary vessel may have an intact or recovered venous system and may, therefore, benefit from transvenous LV lead placement for CRT.
Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia: Success Rates and Complications during 14 Years of Experience
Ahmad Yaminisharif,Gholamreza Davoodi,Ali Kasemisaeid,Ali Vasheghani Farahani
Journal of Tehran University Heart Center , 2010,
Abstract: Background: Radiofrequency catheter ablation (RFCA) has been introduced as the treatment of choice for supraventricular tachycardia. The aim of this study was to evaluate the success rate as well as procedural and in-hospital complications of RFCA for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT).Methods: Between March 1995 and February 2009, 544 patients (75.9% female, age: 48.89 ± 13.19 years) underwent 548 RFCAs for AVNRT in two large university hospitals. Echocardiography was performed for all the patients before and after the procedure. Electrocardiograms were recorded on digital multichannel systems (EP-Med) or Bard EP system. Anticoagulation was initiated during the procedure.Results: From the 548 patients, 36 had associated arrhythmias, atrial flutter (4%), atrial fibrillation (0.7%), concurrent atrial fibrillation and atrial flutter (0.7%), and concealed atrioventricular pathway (0.4%). The overall success rate was 99.6%. There were 21 (3.9%) transient III-degree AV blocks (up to a few seconds) and 4 (0.7%) prolonged II- or III-degree AV blocks, 2 (0.25%) of which required permanent pacemaker insertion, 3(0.5%) deep vein thrombosis, and one (0.2%) arteriovenous fistula following the procedure. No difference was observed in the echocardiography parameters before and after the ablation.Conclusion: RFCA had a high success rate. The complication rate was generally low and in the above-mentioned centers it was similar to those in other large centers worldwide. Echocardiography showed no difference before and after the ablation. The results from this study showed that the risk of permanent II or III-degree AV block in patients undergoing RFCA was low and deep vein thrombosis was the second important complication. There was no risk of life-threatening complications.
Atrial Standstill: A Rare Case
Ahmad Yaminisharif,Akbar Shafiee,Mohammad Sahebjam,Ali Moezzi
Journal of Tehran University Heart Center , 2011,
Abstract: We introduce a 32-year-old man who was evaluated for a dizziness and headache of unknown origin for at least two months and was referred to our center after ECG findings. He was finally diagnosed as a case of idiopathic, familial, diffuse, persistent atrial standstill, which is a rare arrhythmogenic condition characterized by the absence of electrical and mechanical activity in the atria. He successfully received a single-chamber permanent pacemaker.
Radio frequency in treatment of AVNRT arrhythmia
Moghaddam M,Yaminisharif A
Tehran University Medical Journal , 1998,
Abstract: AV-node modification by catheter RF energy delivery is treatment of choice in the symptomatic patients with AVNRT. This study included 30 patients with AVNRT (19 women, 11 men). We did slow pathway ablation in 29 cases successfully. Maximum effective energy delivery was 40 watts for 40 msec. 1:1 AV conduction increased from 290±40 msec before ablation to 340±65 msec after ablation. Also AV-node ERP increased from 235±35 msec before ablation to 280±65 msec after that. There was no recurrence of arrhythmia in the group with slow pathway ablation during 28 months follow-up. We did fast pathway ablation in one case. In this patient AH interval increased from 120 to 200 msec, maximum RF energy delivery was 20 watts for 20 msec (2 times). Recurrence of non sustained PSVT occurred in this patients 20 months after RF ablation. There was no case of permanent AV Block. We recommond slow pathway catheter RF ablation in patients with symptomatic AVNRT.
Desulphurization of Transportation Fuels by Per-Formic Acid Oxidant Using MoOx Loaded on ZSM-5 Catalyst  [PDF]
Waqas Ahmad, Imtiaz Ahmad
Journal of Power and Energy Engineering (JPEE) , 2017, DOI: 10.4236/jpee.2017.512011
Abstract:
Desulphurization of model and real oil samples was investigated using performic acid as oxidant assisted by air as co-oxidant. The catalysts used were Mo-oxide supported on ZSM-5 zeolite, which was synthesized in the laboratory and characterized by FT-IR, XRD, SEM and SSA analysis. In case of model oil, the optimum condition determined for complete oxidation of all the model compounds including thiophene, DBT and 4,6-DMDBT were; 60?C, 60 min, ambient pressure and air flow rate of 100 mL/min. The oxidation reactivity decreased from 4,6-DMDBT to DBT and thiophene, which was found to follow pseudo first order kinetics. The real oil sample used in the study included untreated naphtha (NP), light gas oil (LGO), heavy gas oil (HGO) and Athabasca bitumen (Bit.). In case of NP and LGO the sulfur removal of above 78% was attained whereas in case of HGO and Bit. samples about 60% of desulfurization was achieved.
Efficiency and Duality in Nondifferentiable Multiobjective Programming Involving Directional Derivative  [PDF]
Izhar Ahmad
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.24057
Abstract: In this paper, we introduce a new class of generalized dI-univexity in which each component of the objective and constraint functions is directionally differentiable in its own direction di for a nondifferentiable multiobjective programming problem. Based upon these generalized functions, sufficient optimality conditions are established for a feasible point to be efficient and properly efficient under the generalised dI-univexity requirements. Moreover, weak, strong and strict converse duality theorems are also derived for Mond-Weir type dual programs.
Visco-Elastic Boundary Layer Flow past a Stretching Plate and Heat Transfer with Variable Thermal Conductivity  [PDF]
Naseem Ahmad
World Journal of Mechanics (WJM) , 2011, DOI: 10.4236/wjm.2011.12003
Abstract: In the present paper, the boundary layer flow of Walters Liquid B Model over a stretching plate has been considered to solve heat flow problem with variable conductivity. First, using similarity transformation, the velocity components of velocity have been obtained. Then, the heat flow problem has been considered in two ways: 1) prescribed surface temperature (PST), and 2) prescribed stretching plate heat flux (PHF) in case of variable conductivity. Due to variable conductivity, temperature profile has its two part- one mean tempera-ture and other temperature profile induced due to variable conductivity. The related results have been dis-cussed with the help of graphs.
Intelligent MSW Biocell Approach for Efficient Methane Production  [PDF]
Ahmad Qasaimeh
Computational Water, Energy, and Environmental Engineering (CWEEE) , 2012, DOI: 10.4236/cweee.2012.12003
Abstract: The aim of this research is to provide approach to enhance methane production and to convert CO2 released into methane via anaerobic degradation. Despite CH4 has more global warming potential than CO2 but it is less available in the environment and it has fuel value. This research suggests approach that methane is being stimulated and carbon dioxide is being converted to methane. The methane enhancement herein is achieved via technical and intelligent processes. The technical processes entail leachate and carbon dioxide recirculation. The recirculated leachate is controlled via fuzzy intelligent system that acquires values of abiotic factors such as C:N:P, pH, temperature, and moisture content, and then these values are introduced to trained fuzzy system to decide the value of methane production quality. The fuzzy logic proceeds in systematic sequence as input, inference through rules, and output. If the fuzzy logic output decision indicates bad production, then the value of aboitic factors are dynamically altered with optimized combination of values. Carbon dioxide is being re-circulated in order to convert it biologically to methane by hydrogenotrophic methanogens. The hydrophobic permeable membranes are used as planes through the solid waste. These selective membranes are used to separate biogas and to have smooth and fast transfer of biogas from waste to the storage. The approach of this research is believed to be as a new generation of sustainable green bio-fuel biocells.
Root Analogous Solid Waste Management System (RA-MSW for Biocells)  [PDF]
Ahmad Qasaimeh
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.38090
Abstract: Root Analogous Municipal Solid Waste System “RA-MSW” is a novel management system that manages waste, biogas, and leachate in bioreactor landfill. Different than conventional disposal at landfills, waste is penetrated by synthetic roots that serve dual mission for biogas collection and leachate recirculation. RA-MSW roots are permeable hydropho- bic polymer material that are formed on-place or prefabricated at factory from recyclable material available on the dumping area. Since the material is hydrophobic, it does not contain water in the voids providing more space for gas transport and collection. The roots are also interchangeably used for leachate recirculation where the parameters of wa- ter content, nutrients, pH, and temperature are optimized to enhance biogas production simultaneously with leachate treatment. RA-MSW provides new approach of waste management and control; it has new virtues of landfill operation; new material medium for biogas collection; new biocell design configuration; new manipulation for leachate and biogas. The approach adds new merits for solid waste management, bio-energy utilization, and the concept of 5 R’s cycle for MSW management.
Solar Energy Optimization through Seasons: Case Study in Jordan  [PDF]
Ahmad Qasaimeh
Smart Grid and Renewable Energy (SGRE) , 2012, DOI: 10.4236/sgre.2012.34038
Abstract: Solar energy in Jordan is recognized high amongst in the world. The solar energy cultivation needs to be magnified by optimizing the angle of inclination of solar cells. The angle of inclination in this work is not fixed but variable throughout the year, and consequently the angle is optimized for seasons. In this research, the optimized angles for seasons in Jordan are obtained as: 60? for Winter (November to February), 30? for Spring (March and April), 10? for Summer (May to August), and 30? for Fall (September and October). The optimized cultivated energy throughout all seasons in the year equals about 2490 kWh/m2. The residential customer consumption of electricity is 2475 kWh/customer per year. Therefore, according to Jordan, if the sun energy is converted efficiently to electricity, it will be worthy to apply for residential building for which each customer should have some area of solar cells to overcome the needs of energy. In addition, with some wise management of electricity in the daylight period, fossil fuel consumption will be minimized. Hence, combining solar energy concept in the design of building is an important step in sustainable development of green energy.
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