Prevalence and diagnostic significance of de-novo 12-lead ECG changes after COVID-19 infection in elite soccer players.

BACKGROUND AND AIM: The efficacy of pre-COVID-19 and post-COVID-19 infection 12-lead ECGs for identifying athletes with myopericarditis has never been reported. We aimed to assess the prevalence and significance of de-novo ECG changes following COVID-19 infection. METHODS: In this multicentre observational study, between March 2020 and May 2022, we evaluated consecutive athletes with COVID-19 infection. Athletes exhibiting de-novo ECG changes underwent cardiovascular magnetic resonance (CMR) scans. One club mandated CMR scans for all players (n=30) following COVID-19 infection, despite the absence of cardiac symptoms or de-novo ECG changes. RESULTS: 511 soccer players (median age 21 years, IQR 18-26 years) were included. 17 (3%) athletes demonstrated de-novo ECG changes, which included reduction in T-wave amplitude in the inferior and lateral leads (n=5), inferior leads (n=4) and lateral leads (n=4); inferior T-wave inversion (n=7); and ST-segment depression (n=2). 15 (88%) athletes with de-novo ECG changes revealed evidence of inflammatory cardiac sequelae. All 30 athletes who underwent a mandatory CMR scan had normal findings. Athletes revealing de-novo ECG changes had a higher prevalence of cardiac symptoms (71% vs 12%, p<0.0001) and longer median symptom duration (5 days, IQR 3-10) compared with athletes without de-novo ECG changes (2 days, IQR 1-3, p<0.001). Among athletes without cardiac symptoms, the additional yield of de-novo ECG changes to detect cardiac inflammation was 20%. CONCLUSIONS: 3% of athletes demonstrated de-novo ECG changes post COVID-19 infection, of which 88% were diagnosed with cardiac inflammation. Most affected athletes exhibited cardiac symptoms; however, de-novo ECG changes contributed to a diagnosis of cardiac inflammation in 20% of athletes without cardiac symptoms

Prevalence and diagnostic significance of de-novo 12-lead ECG changes after COVID-19 infection in elite soccer players.

Background and aim: The efficacy of pre-COVID-19 and post-COVID-19 infection 12-lead ECGs for identifying athletes with myopericarditis has never been reported. We aimed to assess the prevalence and significance of de-novo ECG changes following COVID-19 infection. Methods: In this multicentre observational study, between March 2020 and May 2022, we evaluated consecutive athletes with COVID-19 infection. Athletes exhibiting de-novo ECG changes underwent cardiovascular magnetic resonance (CMR) scans. One club mandated CMR scans for all players (n=30) following COVID-19 infection, despite the absence of cardiac symptoms or de-novo ECG changes. Results: 511 soccer players (median age 21 years, IQR 18-26 years) were included. 17 (3%) athletes demonstrated de-novo ECG changes, which included reduction in T-wave amplitude in the inferior and lateral leads (n=5), inferior leads (n=4) and lateral leads (n=4); inferior T-wave inversion (n=7); and ST-segment depression (n=2). 15 (88%) athletes with de-novo ECG changes revealed evidence of inflammatory cardiac sequelae. All 30 athletes who underwent a mandatory CMR scan had normal findings. Athletes revealing de-novo ECG changes had a higher prevalence of cardiac symptoms (71% vs 12%, p<0.0001) and longer median symptom duration (5 days, IQR 3-10) compared with athletes without de-novo ECG changes (2 days, IQR 1-3, p<0.001). Among athletes without cardiac symptoms, the additional yield of de-novo ECG changes to detect cardiac inflammation was 20%. Conclusions: 3% of athletes demonstrated de-novo ECG changes post COVID-19 infection, of which 88% were diagnosed with cardiac inflammation. Most affected athletes exhibited cardiac symptoms; however, de-novo ECG changes contributed to a diagnosis of cardiac inflammation in 20% of athletes without cardiac symptoms

Experimental investigation of various solid particle materials on the steady state gassolid fluidized bed system

The present study provides a comprehensive experimental work about fluidized bed gas-solid system characteristics by using different solid particles. Naphthalene, silica gel and sand (197 µm diameter) are utilized as a solid particles while air is used for fluidization. An experimental rig is build to test the various solid particles and to establish a good description of flow and heat transfer patterns for the fluidized bed gas-solid system. Based on the experimental tests, it is found that the solid particle type has a significant influence on the gas-solid flow dynamics. The experimental tests are performed for various fluidized bed velocities ( 0.8 , 1.2 and 1.6 m/sec ) and when the heat fluxes are varied as 80 , 120 and 160 W respectively. Experimental measurements are carried out under steady state situation. Depending on the experimental results , it can be concluded that sand solid particles are better than silica gel and naphthalene solid particles for heat transfer enhancement. Also, it can found for naphthalene , silica gel and sand solid particles that as the fluidized bed velocity and heat flux increase the temperature distribution along the fluidization column increases. Moreover, an empirical equation based on the experimental measurements which linking between Nusselt number (Nu) , Froude number (Fr) and Reynolds number (Re) is suggested. Comparisons with previously published works on gas-solid fluidized bed system are performed and good agreements between the results are observed

Mechanical properties and fatigue life detection of copper particle filled polyester composite material under rotating bending load

In the present investigation, the fatigue life detection of composite material by adding copper particle of about than 25 μm diameter with 5, 10, 15 % volume fraction, as a reinforcements into the unsaturated polyester polymer composite material on fatigue life detection of composite material were studied experimentally and numerically. Composites were made using hand lay-up technique and evaluated for mechanical and fatigue properties in accordance with ASTM standards. The experimental results of the tensile test showed that adding 15% of copper particle in unsaturated polyester gives maximum ultimate tensile stress. Fatigue tests including test rod specimens made of composite materials under completely reversed cyclic loading in a rotating cantilever reversed bending machine. It is found that, the fatigue life and fatigue strength increase with increasing in the copper percentage volume fraction in unsaturated polyester resin compared with pure polyester composites. The experimental work was compared with numerical work, which was done by using ANSYS/19 and good agreement has been found. The maximum overall difference between the experimental and numerical work was around 9 %

Mechanical properties and fatigue life detection of copper particle filled polyester composite material under rotating bending load

In the present investigation, the fatigue life detection of composite material by adding copper particle of about than 25 μm diameter with 5, 10, 15 % volume fraction, as a reinforcements into the unsaturated polyester polymer composite material on fatigue life detection of composite material were studied experimentally and numerically. Composites were made using hand lay-up technique and evaluated for mechanical and fatigue properties in accordance with ASTM standards. The experimental results of the tensile test showed that adding 15% of copper particle in unsaturated polyester gives maximum ultimate tensile stress. Fatigue tests including test rod specimens made of composite materials under completely reversed cyclic loading in a rotating cantilever reversed bending machine. It is found that, the fatigue life and fatigue strength increase with increasing in the copper percentage volume fraction in unsaturated polyester resin compared with pure polyester composites. The experimental work was compared with numerical work, which was done by using ANSYS/19 and good agreement has been found. The maximum overall difference between the experimental and numerical work was around 9 %