Comparison of the cost-effectiveness of transesophgeal and transthoracic echocardiographies to detect cardioembolic causes of stroke in non-selected patients

Background: Both Transthoracic Echocardiography (TTE) and Transesophgeal Echocardiography (TEE) are effective investigation tools to detect cardioaortic sources of embolism in ischemic stroke. Nevertheless, there are still uncertainties about the cost-effectiveness of these methods in non-selected patients with acute stroke. Objectives: This study aimed to investigate the cost-effectiveness of TTE and TEE using a decision analytic model in non-selected patients with acute ischemic stroke with or without clinical and radiological signs of embolic pattern. Patients and Methods: This cross-sectional cost-effectiveness study was performed in Nemazee hospital affiliated to Shiraz University of Medical Sciences from January 2014 to April 2014. TTE and TEE were performed for all 65 consecutive patients with ischemic stroke (51.3 male, mean age of 69.7 ± 17.9 years). The required data were direct costs related to performance of TTE and TEE, which were obtained from the patients� bills in their charts. A decision analytic model was implemented to assess the cost-effectiveness of these two methods, which demonstrated an Incremental Cost-Ef-fectiveness Ratio (ICER). Effectiveness was determined based on the number of disorders diagnosed using each of the two echoes confirmed by two cardiologists. All analyses were done using Tree Age Pro 2011. Results: The results showed that TEE was more expensive than TTE in non-selected patients. Performing TEE increased the cost by 1494 USD and the effectiveness by 7. As per ICER equation, for each increment unit in the effectiveness, performing TEE would increase the cost by 213.4 USD compared to TTE. TEE was cost-effective in comparison to TTE regardless of age factor considering the cutoff of Gross Domestic Product (GDP) by three for ICER. Moreover, TTE was cost-effective in 41-60-and 61-80-year-old age groups, while TEE was cost-effective in the 41-60-year-old age group. However, none of the techniques was cost-effective in patients above 81 years old. Conclusions: The results of this study can help reduce the unnecessary use of echocardiography by considering the age group and their corresponding risk factors for developing ischemic stroke. © 2018, Iranian Cardiovascular Research Journal. All rights reserved

Comparison of the cost-effectiveness of transesophgeal and transthoracic echocardiographies to detect cardioembolic causes of stroke in non-selected patients

Background: Both Transthoracic Echocardiography (TTE) and Transesophgeal Echocardiography (TEE) are effective investigation tools to detect cardioaortic sources of embolism in ischemic stroke. Nevertheless, there are still uncertainties about the cost-effectiveness of these methods in non-selected patients with acute stroke. Objectives: This study aimed to investigate the cost-effectiveness of TTE and TEE using a decision analytic model in non-selected patients with acute ischemic stroke with or without clinical and radiological signs of embolic pattern. Patients and Methods: This cross-sectional cost-effectiveness study was performed in Nemazee hospital affiliated to Shiraz University of Medical Sciences from January 2014 to April 2014. TTE and TEE were performed for all 65 consecutive patients with ischemic stroke (51.3 male, mean age of 69.7 ± 17.9 years). The required data were direct costs related to performance of TTE and TEE, which were obtained from the patients� bills in their charts. A decision analytic model was implemented to assess the cost-effectiveness of these two methods, which demonstrated an Incremental Cost-Ef-fectiveness Ratio (ICER). Effectiveness was determined based on the number of disorders diagnosed using each of the two echoes confirmed by two cardiologists. All analyses were done using Tree Age Pro 2011. Results: The results showed that TEE was more expensive than TTE in non-selected patients. Performing TEE increased the cost by 1494 USD and the effectiveness by 7. As per ICER equation, for each increment unit in the effectiveness, performing TEE would increase the cost by 213.4 USD compared to TTE. TEE was cost-effective in comparison to TTE regardless of age factor considering the cutoff of Gross Domestic Product (GDP) by three for ICER. Moreover, TTE was cost-effective in 41-60-and 61-80-year-old age groups, while TEE was cost-effective in the 41-60-year-old age group. However, none of the techniques was cost-effective in patients above 81 years old. Conclusions: The results of this study can help reduce the unnecessary use of echocardiography by considering the age group and their corresponding risk factors for developing ischemic stroke. © 2018, Iranian Cardiovascular Research Journal. All rights reserved

Pacemaker twiddler's syndrome

Abstract A 76-yr-old man with unipolar ventricular pacemaker, previously implanted in the right ventricular apex, presented with syncopal attack and twitching of the right pectoralis muscle. He finally was diagnosed as having Twiddler's syndrome. The patient had a pulse rate of 36/min and cannon waves in the neck veins. Chest radiography showed a dislodged pacing lead completely wrapped around the pulse generator. After uncoiling the lead it was positioned in the right ventricular apex and the pulse generator implanted and sewed tightly in a smaller pocket. After six months follow-up there was no further twiddling or pacemaker dysfunction

Path Planning for Mobile Objects in Four-Dimension Based on Particle Swarm Optimization Method with Penalty Function

We present one algorithm based on particle swarm optimization (PSO) with penalty function to determine the conflict-free path for mobile objects in four-dimension (three spatial and one-time dimensions) with obstacles. The shortest path of the mobile object is set as goal function, which is constrained by conflict-free criterion, path smoothness, and velocity and acceleration requirements. This problem is formulated as a calculus of variation problem (CVP). With parametrization method, the CVP is converted to a time-varying nonlinear programming problem (TNLPP). Constraints of TNLPP are transformed to general TNLPP without any constraints through penalty functions. Then, by using a little calculations and applying the algorithm PSO, the solution of the CVP is consequently obtained. Approach efficiency is confirmed by numerical examples