Use of Electrocardiographic Screening to Clear Athletes for Return to Sports Following COVID-19 Infection.

OBJECTIVE: To quantify the occurrence rate of abnormal electrocardiographic (ECG) findings and symptoms following coronavirus disease 2019 (COVID-19) infection. PATIENTS AND METHODS: In this retrospective analysis, we studied adult patients (>18 years old) who were participating in collegiate athletics and previously tested positive for COVID-19 between August 1, 2020, and December 30, 2020. The athletes underwent general examinations and ECG screening prior to being medically cleared for a return to sports following their COVID-19 diagnosis. Predetermined predictors were grouped into categorical variables including (1) sex, (2) symptom severity, and (3) body mass index (normal vs overweight [≥24 kg/m2]). These variables were used to examine differences of abnormal rates that occurred between different predictor categories. RESULTS: Of the 170 athletes screened, 6 (3.5%) presented with abnormal ECG findings and were referred to cardiologists. We found no evidence that sex, symptom severity, and body mass index category were associated with a higher rate of abnormal ECG findings (all P>.05). Greater severity of COVID-19 symptoms was associated with a higher percentage of ST depression, T-wave inversion, ST-T changes, and the presence of fragmented QRS complex. Loss of smell, loss of taste, headache, and fatigue were the most prevalent symptoms, with 38.8% (66), 36.5% (62), 32.9% (56), and 25.3% (43), respectively, of the 170 athletes reporting each symptom. CONCLUSION: Preliminary findings indicate a low risk of myocardial injury secondary to COVID-19 infection, with less than 4% of the 170 patients in our study presenting with abnormal ECG findings and a total of 16 patients (9.4%) requiring referral to a cardiologist. Although viral myocarditis was not detected in any athlete referred for cardiological assessment, 2 patients experienced effusive viral pericarditis.

Sex differences in white matter alterations following repetitive subconcussive head impacts in collegiate ice hockey players.

OBJECTIVE: Repetitive subconcussive head impacts (RSHI) may lead to structural, functional, and metabolic alterations of the brain. While differences between males and females have already been suggested following a concussion, whether there are sex differences following exposure to RSHI remains unknown. The aim of this study was to identify and to characterize sex differences following exposure to RSHI. METHODS: Twenty-five collegiate ice hockey players (14 males and 11 females, 20.6 ± 2.0 years), all part of the Hockey Concussion Education Project (HCEP), underwent diffusion-weighted magnetic resonance imaging (dMRI) before and after the Canadian Interuniversity Sports (CIS) ice hockey season 2011-2012 and did not experience a concussion during the season. Whole-brain tract-based spatial statistics (TBSS) were used to compare pre- and postseason imaging in both sexes for fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). Pre- and postseason neurocognitive performance were assessed by the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). RESULTS: Significant differences between the sexes were primarily located within the superior longitudinal fasciculus (SLF), the internal capsule (IC), and the corona radiata (CR) of the right hemisphere (RH). In significant voxel clusters (p < 0.05), decreases in FA (absolute difference pre- vs. postseason: 0.0268) and increases in MD (0.0002), AD (0.00008), and RD (0.00005) were observed in females whereas males showed no significant changes. There was no significant correlation between the change in diffusion scalar measures over the course of the season and neurocognitive performance as evidenced from postseason ImPACT scores. CONCLUSIONS: The results of this study suggest sex differences in structural alterations following exposure to RSHI. Future studies need to investigate further the underlying mechanisms and association with exposure and clinical outcomes.

Evaluation and analytical validation of a handheld digital refractometer for urine specific gravity measurement.

OBJECTIVES: Refractometers are commonly used to determine urine specific gravity (SG) in the assessment of hydration status and urine specimen validity testing. Few comprehensive performance evaluations are available demonstrating refractometer capability from a clinical laboratory perspective. The objective of this study was therefore to conduct an analytical validation of a handheld digital refractometer used for human urine SG testing. DESIGN AND METHODS: A MISCO Palm Abbe™ refractometer was used for all experiments, including device familiarization, carryover, precision, accuracy, linearity, analytical sensitivity, evaluation of potential substances which contribute to SG (i.e. "interference"), and reference interval evaluation. A manual refractometer, urine osmometer, and a solute score (sum of urine chloride, creatinine, glucose, potassium, sodium, total protein, and urea nitrogen; all in mg/dL) were used as comparative methods for accuracy assessment. RESULTS: Significant carryover was not observed. A wash step was still included as good laboratory practice. Low imprecision (%CV, <0.01) was demonstrated using low and high QC material. Accuracy studies showed strong correlation to manual refractometry. Linear correlation was also demonstrated between SG, osmolality, and solute score. Linearity of Palm Abbe performance was verified with observed error of ≤0.1%. Increases in SG were observed with increasing concentrations of albumin, creatinine, glucose, hemoglobin, sodium chloride, and urea. Transference of a previously published urine SG reference interval of 1.0020-1.0300 was validated. CONCLUSIONS: The Palm Abbe digital refractometer was a fast, simple, and accurate way to measure urine SG. Analytical validity was confirmed by the present experiments.