Left ventricle myocardial deformation in olympic athletes assessed by cardiac magnetic resonance: does the sex and discipline matter?

Funding Acknowledgements

Type of funding sources: None.

Background

Sport induces structural and functional cardiac adaptation with different entity related to several factors including type of training and gender. Cardiovascular Magnetic Resonance (CMR) is the gold standard for morpho-functional evaluation of athletes’ heart and commonly relies on ventricular volume, wall thickness and ejection fraction (EF) assessment. Data on myocardial deformation (MD) are limited to echocardiography and are scarce.

Purpose

To assess MD in Olympic athletes and to evaluate the possible influence of sport categories and gender.

Methods

A group of Olympic athletes evaluated prior the Olympic games with unremarkable cardiovascular pre-participation screening tests underwent CMR without contrast administration. A group of sedentary subjects was enrolled as a control group. Cine-images were post-processed for volume and function evaluation and to assess global longitudinal strain (GLS) and global circumferential strain (GCS) by feature-tracking software. Athletes were divided in subgroups according to ESC sport classification. Male and female athletes were compared. Athletes were also divided based on EF (≤53% or >53%).

Results

93 elite athletes (33% power, 33% mixed, 33% endurance) and 18 controls were enrolled. No differences in terms of EF were observed, while endurance athletes showed the greater LV remodeling (Table). GLS and GCS values of the entire population were -22.5±2.7% and -30.7±3.4%, respectively. No significant differences were found comparing athletes of different sport categories and sedentary controls for GLS (p= 0.940) and GCS (p=0.072). Female athletes showed higher GLS compared to male (-23.5±2.8% vs-21.9±2.8%, p=0.002) but not differences in terms of GCS (-31.5±3.1% vs-30.2±3.5%, p=0.076). Athletes with EF≤53% had lower GLS values compared with those with >53% but within normal limits (Figure).

Conclusion

No differences were observed in MD assessed by CMR between different sport categories and controls. Female athletes showed higher longitudinal but not circumferential strain compared with male. Athletes with lower EF presented lower values of strain but within normal range with the potentiality to be used as a tool for differential diagnosis between normal adaptation and disease.

Cardiovascular screening in olympic athletes before and after SARS-CoV-2 infection

Funding Acknowledgements

Type of funding sources: None.

Background

Conflicting results on the cardiovascular involvement after SARS-CoV-2 infection generated concerns on the safety of return-to-play (RTP) in the athletic population. However, these data are mainly based on Troponin and imaging findings.

Purpose

Aim of the study was to evaluate the prevalence of cardiac involvement after COVID-19 in Olympic athletes, who had previously been screened in our pre-participation program.

Methods

Since November 2020, all consecutive Olympic athletes presented to our Institute after COVID-19 prior RTP were enrolled. The protocol was dictated by the Italian governing bodies and comprised: 12-lead ECG, blood test, cardiopulmonary exercise test (CPET), 24-hours ECG monitoring, spirometry. Cardiovascular Magnetic Resonance (CMR) was also performed. All Athletes were previously screened in our Institute as part of their periodical pre-participation evaluation.

Results

Forty-seven Italian Olympic athletes were enrolled: 83% asymptomatic, 13% mildly asymptomatic, 4% had pneumonia. The evaluation was performed after a median of 9 days from negative SARS-CoV-2 swab. Uncommon premature ventricular contractions (PVCs) were found in 13% athletes, however, only 6% (n=3) were newly detected. All newly diagnosed uncommon PVCs were detected by CPET. One of these three athletes had evidence for acute myocarditis by CMR, along with Troponin raise; another had mild pericardial effusion. No one of the remaining athletes had abnormalities detected by CMR (Figure).

Conclusions

Cardiac abnormalities in Olympic athletes screened after COVID-19 resolution were detected in a minority and were associated with new ventricular arrhythmias. Only one had evidence for acute myocarditis (in presence of symptoms and elevated biomarkers). No one of the remaining athletes had abnormalities by imaging or laboratory test. Our data support the efficacy of the clinical assessment including exercise-ECG to raise suspicion for cardiovascular abnormalities after COVID-19. Instead, the routine use of CMR as a screening tool appears not justified.

Hemodynamic forces in olympic athletes assessed by cardiac magnetic resonance: a new non-invasive screening tool?

Funding Acknowledgements

Type of funding sources: None.

Background

Non-invasive evaluation of left ventricular hemodynamic forces (HDFs) by Cardiac Magnetic Resonance (CMR) is a promising tool to improve systolic and diastolic evaluation. No data are available on athletic population.

Purpose

To provide the range of normal values of HDFs in Olympic athletes and to evaluate the possible influence of different sport categories.

Methods

A group of Olympic athletes evaluated prior the Olympic games with unremarkable cardiovascular pre-participation screening tests underwent CMR without contrast administration. A group of sedentary subjects was enrolled as a control group. Cine-images were post-processed by a feature-tracking based software to estimate HDFs. HDFs were measured in apex-base (AB) and latero-septal (LS) directions, over the entire heartbeat, in systole and diastole. Athletes were divided in subgroups according to ESC sport classification for comparison. They were also divided according to the ejection fraction (EF ≤ or >53%).

Results

93 elite athletes (33% power, 33% mixed, 33% endurance) were enrolled. HDFs in AB and LS direction were 20.5%± 4.3 and 2.9%± 0.7 in the entire heartbeat, 32.6% ± 7 and 3.6%± 1 in systole, 11%± 4.1 and 2.3%± 0.8 in diastole. Comparing athletes of different sport category and sedentary controls no significant differences were found between groups (Table). Comparing athletes with ejection fraction (EF) £ 53% and > 53%, the former showed lower values of AB-HDFs assessed in the entire heartbeat and in systole (18.9 ± 4.6 % vs 20.9 ± 4.1; p= 0.024 and 29.6 ± 6.3 vs 33.3 ± 7; p= 0.024, respectively), but within the normal range.

Conclusion

We provide normal range for HDFs assessed by CMR in elite athletes and no differences were observed between sedentary controls and athletes involved in different sport categories. Comparing athletes with low-normal and normal ejection fraction, the former showed lower values of AB-HDFs but within the normal range.

Low prevalence of cardiac abnormalities in competitive athletes before the return-to-play after COVID-19 based on the italian strategy

Funding Acknowledgements

Type of funding sources: None.

Background

Conflicting results on the cardiovascular involvement after SARS-CoV-2 infection generated concerns on the safety of return-to-play (RTP) in the athletic population. However, data are limited to the approached based on Troponine, ECG and echocardiogram while the data on exercise test are scarce.

Purpose

Aim of the study was to evaluate the prevalence of cardiac involvement after COVID-19 in competitive athletes for the RTP applying a comprehensive cardiovascular evaluation.

Methods

Since October 2020, all consecutive competitive athletes (age≥14 years) presented to our Institute after COVID-19 prior RTP were enrolled. The protocol was dictated by the Italian governing bodies and comprised: 12-lead ECG, blood test, cardiopulmonary exercise test (CPET), 24-hours ECG monitoring, spirometry. Cardiovascular Magnetic Resonance (CMR) was performed based on clinical indication.

Results

219 competitive athletes were enrolled (59% male), age 23 years (19,27): 20% asymptomatic, 77% mildly asymptomatic, 2% had pneumonia. The evaluation was performed after a median of 10 days (6-17 days) from negative SARS-CoV-2 swab. All athletes had a good performance at CPET. Uncommon premature ventricular contractions (PVCs) were found in 10% (n=21) and were detected by CPET. Two athletes (1%) were finally diagnosed with acute myocarditis (confirmed by CMR) and another had newly diagnosed mild pericardial effusion (Figure). All the three athletes were temporally refrain from sport participation.

Conclusions

Cardiac abnormalities in competitive athletes screened after COVID-19 resolution were detected in a minority of the cases (1.4%). No one of the remaining athletes had abnormalities by imaging or laboratory test neither reduction in cardiopulmonary fitness. Our data are in line with those reporting low prevalence of cardiovascular complication in mildly symptomatic or symptomatic athletes.

Positive CMR findings are associated with polymorphic ventricle arrhythmias and ECG repolarization changes but not with exercises induced arrhythmias in competitive and non-competitive athletes

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiac magnetic resonance (CMR) provides an effective contribution for the prevention of sudden cardiac death with its ability to provide accurate information on morpho-functional abnormalities and on myocardial tissue characterization. However, data on its utility in clinical scenario in the competitive athletes are limited to selected cohort of patients with complex arrhythmias.

Objective

To retrospectively analyze all the CMR performed at our center for evaluating the predictors of positive CMR findings in a large cohort of competitive and non-competitive athletes presenting with different clinical indications.

Methods

Over a period of 30 months all the CMR performed on athletes aged > 14 years and training for at least 5 hours per week at our Institutes were retrospectively recruited. The following data were also collected: medical history, ECG, echocardiography, exercise testing. CMR were categorized as "positive" or "negative" based on the presence or absence of late gadolinium enhancement (LGE, excluding RV insertion point) and/or morphological and/or functional abnormalities. Predictors of "positive" CMR were explored.

Results

503 CMR were recruited and the most frequent indications for CMR were: ventricular arrythmias (n= 213, 42%), ECG abnormalities (n= 140, 28%) followed by echocardiogram abnormalities, symptoms and family history (Figure A). 308 (61%) CMR were "negative" and 195 (39%) "positive" (Figure B). Uncommon ventricular arrythmias did not result associated with positive CMR (p= 0.43), while polymorphic ventricular beats are associated with positive CMR (p= 0.02). Among ECG abnormalities only T-waves inversion, particularly on lateral and infero-lateral leads, were associated with positive CMR (p= 0.04).

Conclusion

Ventricular arrhythmias represented the most common indication for require a CMR but in almost half the cases, the CMR was negative. Excises induced ventricular arrhythmias is not significantly associated with pathological findings on CMR, while the polymorphic morphology of arrhythmias and the presence of lateral and infero-lateral repolarization abnormalities on ECG were associated with positive CMR.

Deliberating performance targets workshop: Potential paths for emerging PM2.5 and O3 air sensor progress

The United States Environmental Protection Agency held an international two-day workshop in June 2018 to deliberate possible performance targets for non-regulatory fine particulate matter (PM_2.5) and ozone (O₃) air sensors. The need for a workshop arose from the lack of any market-wide manufacturer requirement for Ozone documented sensor performance evaluations, the lack of any independent third party or government-based sensor performance certification program, and uncertainty among all users as to the general usability of air sensor data. A multi-sector subject matter expert panel was assembled to facilitate an open discussion on these issues with multiple stakeholders. This summary provides an overview of the workshop purpose, key findings from the deliberations, and considerations for future actions specific to sensors. Important findings concerning PM_2.5 and O₃ sensors included the lack of consistent performance indicators and statistical metrics as well as highly variable data quality requirements depending on the intended use. While the workshop did not attempt to yield consensus on any topic, a key message was that a number of possible future actions would be beneficial to all stakeholders regarding sensor technologies. These included documentation of best practices, sharing quality assurance results along with sensor data, and the development of a common performance target lexicon, performance targets, and test protocols.

Carbon nanotube films as a platform to transduce molecular recognition events in metalloporphyrins

Porphyrins have been widely used for many years as functional materials for chemical sensors. Their outstanding chemical features are balanced by some restrictions in terms of transduction techniques. In particular, porphyrin layers are barely conductive, with the consequence that the fabrication of porphyrin based chemiresistors is not possible, except in few rare cases. On the other hand, carbon nanotubes (CNTs) have superior electric properties ranging from metallic to semiconductor in character. Although the conductivity of CNTs is very sensitive to adsorbed molecules, it should be considered that the adsorption onto carbon structures is also scarcely selective and cannot be modified unless other molecular recognition systems are coupled with the CNTs. Following this approach, in this paper we investigated the sensing properties of hybrid CNT-porphyrin films to explore the possibility of transducing the adsorption events occurring in a porphyrin layer into resistance changes of the CNT layers. The results obtained indicate that the presence of the porphyrin films increases the sensitivity of the electric resistance of the CNTs to the concentration of volatile compounds. This enhancement is probably due to the catalytic effect of the metalloporphyrin in conveying the charge transfer from the adsorbate molecule to the CNTs substrate. This property of metalloporphyrins may introduce a further differentiation between porphyrin based sensors that could be positively utilized in sensor array configurations.

Metal-modified and vertically aligned carbon nanotube sensors array for landfill gas monitoring applications

Vertically aligned carbon nanotube (CNT) layers were synthesized on Fe-coated low-cost alumina substrates using radio-frequency plasma enhanced chemical vapour deposition (RF-PECVD) technology. A miniaturized CNT-based gas sensor array was developed for monitoring landfill gas (LFG) at a temperature of 150 degrees C. The sensor array was composed of 4 sensing elements with unmodified CNT, and CNT loaded with 5 nm nominally thick sputtered nanoclusters of platinum (Pt), ruthenium (Ru) and silver (Ag). Chemical analysis of multicomponent gas mixtures constituted of CO(2), CH(4), H(2), NH(3), CO and NO(2) has been performed by the array sensor responses and pattern recognition based on principal component analysis (PCA). The PCA results demonstrate that the metal-decorated and vertically aligned CNT sensor array is able to discriminate the NO(2) presence in the multicomponent mixture LFG. The NO(2) gas detection in the mixture LFG was proved to be very sensitive, e.g.: the CNT:Ru sensor shows a relative change in the resistance of 1.50% and 0.55% for NO(2) concentrations of 3.3 ppm and 330 ppb dispersed in the LFG, respectively, with a wide NO(2) gas concentration range measured from 0.33 to 3.3 ppm, at the sensor temperature of 150 degrees C. The morphology and structure of the CNT networks have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. A forest-like nanostructure of vertically aligned CNT bundles in the multi-walled form appeared with a height of about 10 microm and a single-tube diameter varying in the range of 5-35 nm. The intensity ratio of the Raman spectroscopy D-peak and G-peak indicates the presence of disorder and defects in the CNT networks. The size of the metal (Pt, Ru, Ag) nanoclusters decorating the CNT top surface varies in the range of 5-50 nm. Functional characterization based on electrical charge transfer sensing mechanisms in the metal-modified CNT-chemoresistor array demonstrates high sensitivity by providing minimal sub-ppm level detection, e.g., download up to 100 ppb NO(2), at the sensor temperature of 150 degrees C. The gas sensitivity of the CNT sensor array depends on operating temperature, showing a lower optimal temperature of maximum sensitivity for the metal-decorated CNT sensors compared to unmodified CNT sensors. Results indicate that the recovery mechanisms in the CNT chemiresistors can be altered by a rapid heating pulse from room temperature to about 110 degrees C. A comparison of the NO(2) gas sensitivity for the chemiresistors based on disorderly networked CNTs and vertically aligned CNTs is also reported. Cross-sensitivity towards relative humidity of the CNT sensors array is investigated. Finally, the sensing properties of the metal-decorated and vertically aligned CNT sensor arrays are promising to monitor gas events in the LFG for practical applications with low power consumption and moderate sensor temperature.

Alternatives to animal experimentation for hormonal compounds research

Alternatives to animal testing and the identification of reliable methods that may decrease the need for animals are currently the subject of intense investigation worldwide. Alternative testing procedures are particularly important for synthetic and natural chemicals that exert their biological actions through binding nuclear receptors, called nuclear receptors-interacting compounds (NR-ICs), for which research is increasingly emphasizing the limits of several models in the accurate estimation of the physiological consequences of exposure to these compounds. In particular, estrogen receptor interacting compounds (ER-ICs) have a great impact on human health from the therapeutic, nutritional, and toxicological point of view due to the highly permissive nature of the estrogen receptors towards a large number of natural and synthetic compounds. Similar to in vitro systems, recently generated animal models (e.g., animal models generated for the study of estrogen receptor ligands) may fulfill the 3R principles: refine, reduce, and replace. If used correctly, NR-regulated models, such as reporter mice, xenopus, or zebrafish, and models obtained by somatic gene transfer in reporter systems, combined with imaging technologies, may contribute to strongly decreasing the overall number of animals required for NR-IC testing and research. With these models, flexible and highly standardized parameters and reporter marker quantification can be obtained. Here, we highlight the need for the substitution of currently used testing models with more appropriate ones that can reproduce the features and reactivity of specific mammalian target tissue/organs. We consider the promotion of this advancement a research priority bearing scientific, economic, social, and ethical relevance.

Genistein affects adipose tissue deposition in a dose-dependent and gender-specific manner

The soy isoflavone genistein targets adipose tissue and elicits physiological effects that may vary based on dietary intake. We hypothesized that the adipose effects of genistein are dose and gender dependent. Four-week-old C57BL/6 male and female mice received daily oral doses of genistein (50-200,000 microg/kg.d) or 17beta-estradiol (E2) (5 microg/kg.d) for 15 d or a diet containing 800 ppm genistein. Genistein increased epididymal and renal fat pad and adipocyte size at doses up to 50,000 microg/kg.d or at 800 ppm in the diet in males but not in females. The alteration in adipocity correlated with changes in peripheral insulin resistance. These treatments increased genistein serum concentrations from 35+/-6 to 103+/-26 nM 12 h after treatment and lowered plasma triglycerides and cholesterol levels. The 200,000 microg/kg.d genistein dose decreased adipose tissue weight similarly to E2. This genistein dose down-regulated estrogen receptor (beta more than alpha) and progesterone receptor expression and induced estrogen-dependent adipose differentiation factors; it did not change expression of the minimal consensus estrogen-responsive element in ERE-tK-LUC mice, which was positively modulated in other tissues (e.g. the lung). E2 down-regulated almost all examined adipogenic factors. Gene microarray analysis identified factors in fat metabolism and obesity-related phenotypes differentially regulated by low and high doses of genistein, uncovering its adipogenic and antiadipogenic actions. The lower dose induced the phospholipase A2 group 7 and the phospholipid transfer protein genes; the 200,000 microg/kg.d dose inhibited them. The antiadipogenic action of genistein and down-regulation of adipogenic genes required the expression of ERbeta. In conclusion, nutritional doses of genistein are adipogenic in a gender-specific manner, whereas pharmacological doses inhibited adipose deposition.

Whole body action of xenoestrogens with different chemical structures in estrogen reporter male mice

The present work tested the estrogenic activity of three weak environmental estrogens p,p'DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane], p,p'DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] and betaBHC [beta-benzene-hexachloride] in the transgenic estrogen-reporter mouse model (ERE-tK-LUC). By a time dependent analysis of the transgenic reporter expression (luciferase), we showed that all these chemicals modulated the estrogen receptors (ERs) in the whole body, although with a different efficacy and depending upon the tissue analyzed. Peak activity was registered at 16 h of treatment with 5000 microg/kg of each compound. Organochlorines are lipophylic molecules that accumulate in fat. During weight loss they are mobilized and their concentration increases in blood. We tested whether after experimental accumulation in fat tissue, followed by a 48 h period of fasting, these compounds could be modulated to reach sufficient levels to activate the ERs in target tissues. This experimental setting produced results that were different from those obtained following acute treatments. In loaded mice, fasting induced betaBHC mobilization resulted in strong ER activation in the liver, lung, eye, cerebellum, hypothalamus and cortex. p,p'DDT mobilization had no effect in these tissues, but efficiently acted in the testis, where, on the contrary, betaBHC inhibited reporter expression. During fasting, betaBHC, p,p'DDT and the metabolite p,p'DDE increased in blood concentration, from 2.7 +/- 0.36, 0.65 +/- 0.01 and 0.48 +/- 0.06 microg/ml to 9.51 +/- 1.1, 4.98 +/- 0.77 and 6.0 +/- 0.71 microg/ml, respectively. We conclude that these organochlorines modulate differently the expression of estrogen regulated genes in a tissue- and compound-specific manner and that their action is dependent on the energy balance. Moreover, we show that this mouse model is suitable to detect the estrogenic activity of chemicals with variable structures such as alkyl phenols and polychlorobiphenyls.

Gas sensing properties of Langmuir-Blodgett polypyrrole film investigated by surface acoustic waves

The gas sensing properties of organic polypyrrole (PPS) film, deposited onto LiNbO(3) substrate by Langmuir-Blodgett (LB) technique, have been monitored by surface acoustic wave (SAW) delay lines and studied with respect to sensitivity, selectivity, response time, stability, repeatability, and aging. The SAW PPy elements demonstrate high sensitivity toward NH(3) gas with high selectivity against CH(4), CO, H(2), and O(2). The detectable threshold concentration has been estimated as 20 ppm NH(3) in air; the response time is in the 10s range, and the recovery time is about 15 min; the repeatability of the SAW response toward eight sequential NH(3) gas exposures is within 6%; the aging of the PPy film is within 4% over a month; and the effect of humidity on SAW NH(3) gas response is negligible for the typical conditions at room ambient air. Partially reversible SAW response recognizing NH(3) gas as one component of an interfering gases-mixture has been observed. Simultaneous chemoresponses of SAW phase and insertion loss have been performed in order to investigate the sensing mechanisms. By merging with electrical conductivity gas response, the dominant SAW sensing effects for NH(3 ) gas detection are defined as elastic loading.