Introduction: Exercise echocardiography is a non-invasive technique that occupies a special place for the detection of stable coronary disease. The main objective of this study was to report our experience and assess ...Introduction: Exercise echocardiography is a non-invasive technique that occupies a special place for the detection of stable coronary disease. The main objective of this study was to report our experience and assess our practice in the diagnosis of stable coronaryartery disease. Methodology: We conducted a retrospective study, descriptive over a period of 34 months, from December 1, 2016 to September 30, 2019. All the patients received during the study period for stress echocardiography as part of a suspicion of stable coronary artery disease were included. A total of 100 examinations were completed during the study period. Results: Ninety (90) exams were studied. There were 56 men or a sex-ratio of 1.64. The mean age was of 57.3 ± 10 years. Hypertension (31 patients or 62%) was the most frequent risk factor. Typical chest pain was noticed in 45 patients (52.3%). The pre-test probability was intermediate in 77 patients (89.5%). Echocardiography at rest was normal in 86 patients (95.6%). A total of 62 tests were negative (69%) and 02 (2.2%) were non-contributory. Ten tests (10) of 26 electrical positive tests were associated with segmental kinetics disorders. In the 10 patients who had exercise kinetic disorders, 08 had coronary angiography. It was normal in 04 of them. The positive predictive value of exercise echography was 50% in our study. In a patient with a negative exercise echocardiography with a high clinical probability of coronary disease, the coronary angiography showed a two-vessel impairment with an intermediate lesion of Cx2 and an intermediate lesion of RCA2. It thus constitutes a false negative. Sensitivity was 80% in our study. We noticed an incident like non-sustained ventricular tachycardia. Conclusion: Exercise echocardiography is a safe and reliable examination for the diagnosis of stable coronary artery disease. A good selection of patients based on the clinical probability of coronary ischemia should improve our sensitivity. This is even more important in sub-Saharan Africa, where access to coronary angiography is limited.展开更多
The EU H2020 ORCHYD project seeks to enhance drilling efficiency in hard rock environments,particularly for deep geothermal wells,by integrating innovative rock weakening techniques.In this context,3D finite element s...The EU H2020 ORCHYD project seeks to enhance drilling efficiency in hard rock environments,particularly for deep geothermal wells,by integrating innovative rock weakening techniques.In this context,3D finite element simulations of bit-rock interactions were performed to assess how combining high pressure water jetting(HPWJ)-induced groove and bottom-hole geometry can contribute to improve the down-hole percussive drilling performance.A Red Bohus granite rock was modelled using a continuum,elasto-visco-plastic,and damage-based model calibrated using Brazilian,uniaxial compression,and triaxial material tests as well as single insert impact tests.Bit-rock interaction with an HPWJ groove was studied through modelling of twelve different groove depths and bottom-hole configurations.Results demonstrate that deeper grooves significantly reduce impact loads by up to 35%and increase penetration up to 40%,leading to higher material removal(up to 240%).Groove depth also influences damage propagation between adjacent indents,with grooves facilitating a broader zone of fractured rock,particularly near the groove itself.Notably,the drilling efficiency benefits from HPWJ slotting are highly dependent on bit design:flat and concave bit profiles exhibit 70%greater improvement in drilling performance compared to other profiles.展开更多
文摘Introduction: Exercise echocardiography is a non-invasive technique that occupies a special place for the detection of stable coronary disease. The main objective of this study was to report our experience and assess our practice in the diagnosis of stable coronaryartery disease. Methodology: We conducted a retrospective study, descriptive over a period of 34 months, from December 1, 2016 to September 30, 2019. All the patients received during the study period for stress echocardiography as part of a suspicion of stable coronary artery disease were included. A total of 100 examinations were completed during the study period. Results: Ninety (90) exams were studied. There were 56 men or a sex-ratio of 1.64. The mean age was of 57.3 ± 10 years. Hypertension (31 patients or 62%) was the most frequent risk factor. Typical chest pain was noticed in 45 patients (52.3%). The pre-test probability was intermediate in 77 patients (89.5%). Echocardiography at rest was normal in 86 patients (95.6%). A total of 62 tests were negative (69%) and 02 (2.2%) were non-contributory. Ten tests (10) of 26 electrical positive tests were associated with segmental kinetics disorders. In the 10 patients who had exercise kinetic disorders, 08 had coronary angiography. It was normal in 04 of them. The positive predictive value of exercise echography was 50% in our study. In a patient with a negative exercise echocardiography with a high clinical probability of coronary disease, the coronary angiography showed a two-vessel impairment with an intermediate lesion of Cx2 and an intermediate lesion of RCA2. It thus constitutes a false negative. Sensitivity was 80% in our study. We noticed an incident like non-sustained ventricular tachycardia. Conclusion: Exercise echocardiography is a safe and reliable examination for the diagnosis of stable coronary artery disease. A good selection of patients based on the clinical probability of coronary ischemia should improve our sensitivity. This is even more important in sub-Saharan Africa, where access to coronary angiography is limited.
基金supported by the ORCHYD project,an EU Horizon 2020 research and innovation programme under grant agreement N101006752.
文摘The EU H2020 ORCHYD project seeks to enhance drilling efficiency in hard rock environments,particularly for deep geothermal wells,by integrating innovative rock weakening techniques.In this context,3D finite element simulations of bit-rock interactions were performed to assess how combining high pressure water jetting(HPWJ)-induced groove and bottom-hole geometry can contribute to improve the down-hole percussive drilling performance.A Red Bohus granite rock was modelled using a continuum,elasto-visco-plastic,and damage-based model calibrated using Brazilian,uniaxial compression,and triaxial material tests as well as single insert impact tests.Bit-rock interaction with an HPWJ groove was studied through modelling of twelve different groove depths and bottom-hole configurations.Results demonstrate that deeper grooves significantly reduce impact loads by up to 35%and increase penetration up to 40%,leading to higher material removal(up to 240%).Groove depth also influences damage propagation between adjacent indents,with grooves facilitating a broader zone of fractured rock,particularly near the groove itself.Notably,the drilling efficiency benefits from HPWJ slotting are highly dependent on bit design:flat and concave bit profiles exhibit 70%greater improvement in drilling performance compared to other profiles.
