Atrial Arrhythmias in Patients with Severe COVID-19

The number of confirmed COVID-19 cases has increased drastically; however, information regarding the impact of this disease on the occurrence of arrhythmias is scarce. The aim of this study was to determine the impact of COVID-19 on arrhythmia occurrence. This prospective study included patients with COVID-19 treated at the Leishenshan Temporary Hospital of Wuhan City, China, from February 24 to April 5, 2020. Demographic, comorbidity, and arrhythmias data were collected from patients with COVID-19 (n = 84) and compared with control data from patients with bacterial pneumonia (n = 84) infection. Furthermore, comparisons were made between patients with severe and nonsevere COVID-19 and between older and younger patients. Compared with patients with bacterial pneumonia, those with COVID-19 had higher total, mean, and minimum heart rates (all P < 0.01 ). Patients with severe COVID-19 (severe and critical type diseases) developed more atrial arrhythmias compared with those with nonsevere symptoms. Plasma creatine kinase isoenzyme (CKMB) levels ( P = 0.01 ) were higher in the severe group than in the nonsevere group, and there were more deaths in the severe group than in the nonsevere group (6 (15%) vs. 3 (2.30%); P = 0.05 ). Premature atrial contractions (PAC) and nonsustained atrial tachycardia (NSAT) were significantly positively correlated with plasma CKMB levels but not with high-sensitive cardiac troponin I or myoglobin levels. Our data demonstrate that COVID-19 patients have higher total, mean, and minimum heart rates compared with those with bacterial pneumonia. Patients with severe or critical disease had more frequent atrial arrhythmias (including PAC and AF) and higher CKMB levels and mortality than those with nonsevere symptoms.

High-Acceleration Movement, Muscle Damage, and Perceived Exertion in Basketball Games

Purpose: To evaluate the effect of the number of high-acceleration movements on muscle damage and the rating of perceived exertion (RPE) in basketball games. Methods: Twenty-one male collegiate basketball players (mean age, 20.0 [1.0] y) were included. A triaxial accelerometer was used to measure acceleration in basketball-simulated scrimmages. To detect higher physical load during the actual game, the resultant acceleration was calculated, and 3 thresholds were set: >4G, >6G, and >8G resultant accelerations. The number of the extracted movements was calculated at each acceleration threshold. Plasma creatine kinase (CK) levels (marker of muscle damage) were estimated before and 24 hours after the match, and the session-RPE load was calculated within 30 minutes after the match. Pearson product-moment correlations with 95% confidence intervals were used to determine the relationships between the number of high-acceleration movements and plasma CK and session-RPE load. Results: Significant correlations were observed between the number of high-acceleration movements >8G and CK level (r = .74; 95% confidence interval, 0.44–0.89; P < .0001). Furthermore, the correlation coefficient between acceleration and CK increased with increased acceleration threshold (>4G: r = .65; >6G: r = .69). Contrastingly, the correlation coefficient between acceleration and the session-RPE load decreased with increased acceleration threshold (>4G: r = .72; >6G: r = .52; >8G: r = .43). Conclusions: The session-RPE reflects the total amount of movement, while the high-acceleration movement reflects the momentary large impact load or intensity, and they evaluated different factors. Basketball coaching and conditioning professionals recommended combining acceleration and session-RPE when monitoring the load of athletes.

Plasma creatine kinase and all-cause mortality in patients on peritoneal dialysis: a multi-center retrospective study

Background: Higher plasma creatine kinase (CK) values are associated with the failure of antihypertensive treatment. However, an association between CK and all-cause mortality in peritoneal dialysis (PD) patients has received little attention.Methods: In this retrospective multicenter study, 2224 incident PD patients with baseline CK values were enrolled from November 1, 2005, to February 28, 2017. All patients with oral statins were excluded and then were divided into four groups [Quartile 1 (<60 U/L), Quartile 2 (60-100 U/L), Quartile 3 (101-179 U/L), and Quartile 4 (>179 U/L)]. The primary endpoint was all-cause mortality. The association between plasma CK values and all-cause mortality was assessed with Cox regression and the Fine and Gray models.Results: Of eligible 1382 patients, 298 (21.6%) patients died during a median 35-month (interquartile range=19-54 months) follow-up period. Patients in Quartile 4 were older (P<0.001), more likely to be male (P<0.001), had a higher prevalence of diabetes (P=0.002), and a history of cardiovascular disease (P=0.005), and higher values of Charlson comorbidity index (P=0.031). All-cause mortality incidence had a significant difference among the four Quartiles (Quartile 1, 16.2%; Quartile 2, 22.2%; Quartile 3, 23.8%; Quartile 4, 24.1%; P=0.043). Quartile 4 had a higher all-cause mortality compared to other groups (Log Rank=10.55, P=0.015). After adjusting for confounding factors, the highest CK quartile had a hazard ratio (HR) for all-cause mortality of 1.72 [95% confidence interval (CI) 1.31-3.26, P=0.042]. With kidney transplantation or hemodialysis as a competing risk, the Quartile 4 had an HR for all-cause mortality of 1.64 (95%CI 1.25-3.48, P=0.046), after adjusting for confounding factors. Conclusions: Higher plasma CK levels at the commencement of PD may be a valuable biomarker for predicting the development of all-cause mortality in PD patients.

The Relationship Between muscle Damage and Activity Profiles During Team Handball Matches

Background: Anaerobic activities often require explosive muscle power; it is therefore possible that players’ skeletal muscles sustain damage during the game, which leads to a performance decrease as the game progresses. Objective: This study investigated the relationship between muscle damage and activity profiles during team handball matches. Methods: This study conducted two handball games to examine the relationship between muscle damage and impacts against the body during the games. We studied one handball match between members of the same university team (Game I: 12 male court players) and a practice match between a Japanese handball league team and the university student team (Game II: nine male court players and six controls). Results: Plasma myoglobin concentration and plasma creatine kinase activity, both of which are biomarkers for muscle damage, increased to above their normal ranges after both games. The magnitudes of the changes in both plasma myoglobin (p<.05) and plasma creatine kinase activity (p<0.05) from before to after the game were significantly different between the players and controls in Game II. There were significant correlations between the number of shots taken in Game II and biomarkers for muscle damage; the changes in plasma myoglobin concentrations (p<0.01) and plasma creatine kinase (p< 0.01) activity levels. Conclusion: These results suggest that team handball matches involve high-intensity exercise that is sufficient to cause muscle damage. Additionally, our findings suggest that the severity of muscle damage is related to the specific actions associated with taking shots, such as jumping and colliding with a defender.

Plasma creatine kinase and all-cause mortality in patients on peritoneal dialysis: a multi-center retrospective study

Background Higher plasma creatine kinase (CK) values are associated with the failure of antihypertensive treatment. However, an association between CK and all-cause mortality in peritoneal dialysis (PD) patients has received little attention.Methods In this retrospective multicenter study, 1382 incident PD patients with baseline CK values were enrolled from November 1, 2005, to February 28, 2017. All patients with oral statins were excluded and then were divided into four groups according to quartile range [Quartile 1 (<60 U/L), Quartile 2 (60-100 U/L), Quartile 3 (101-179 U/L), and Quartile 4 (>179 U/L)]. The primary endpoint was all-cause mortality. The association between plasma CK values and all-cause mortality was assessed with Cox regression and the Fine and Gray models.Results Of 1382 patients 298 (21.6%) patients died during a median 35-month (interquartile range=19-54 months) follow-up period. Patients in Quartile 4 were older (P<0.001), likely to be male (P<0.001), had a higher prevalence of diabetes (P=0.002), and a history of cardiovascular disease (P=0.005), and higher values of Charlson comorbidity index (P=0.031). All-cause mortality incidence was a significant difference among the four Quartiles (Quartile 1, 16.2%; Quartile 2, 22.2%; Quartile 3, 23.8%; Quartile 4, 24.1%; P=0.043). Cumulative all-cause mortality in the Quartile 4 was significantly higher compared with other groups (Log Rank=10.55, P=0.015). After adjusting for confounding factors, the highest CK quartile had a hazard ratio (HR) for all-cause mortality of 1.75 [95% confidence interval (CI) 1.34-3.20, P=0.041]. With kidney transplantation or hemodialysis as a competing risk, the Quartile 4 had an HR for all-cause mortality of 1.66 (95%CI 1.30-3.41, P=0.044), after adjusting for confounding factors.Conclusions Higher plasma CK levels at the commencement of PD may be a valuable biomarker for predicting the development of all-cause mortality in PD patients.

The Effects of Leucine-Enriched Branched-Chain Amino Acid Supplementation on Recovery After High-Intensity Resistance Exercise

Context: Of the 3 branched-chain amino acids (BCAA), leucine has arguably received the most attribution for the role of BCAA supplementation in alleviating symptoms of exercise-induced muscle damage and facilitation of acute performance recovery. Purpose: To examine whether enrichment of a standard BCAA supplement with additional leucine or a standalone leucine (LEU) supplement differentially affects exercise-induced muscle damage and performance recovery compared with a standard BCAA supplement. Methods: A total of 22 recreationally active male and female subjects were recruited and assigned to consume a BCAA, leucine-enriched BCAA (LBCAA), or LEU supplement for 11 d. On the eighth day, subjects performed eccentric-based resistance exercise (ECRE). Lower-body mean average and peak power, plasma creatine kinase, soreness, and pain threshold were measured before and 24, 48, and 72 h after ECRE. Results: LEU showed decreased mean average power (P = .02) and mean peak power (P = .01) from baseline to 48 h post-ECRE, whereas LBCAA and BCAA only trended toward a reduction at 24 hours post-ECRE. At 48 h post-ECRE, BCAA showed greater recovery of mean peak power than LEU (P = .04). At 24 h post-ECRE, LEU demonstrated a greater increase in plasma creatine kinase from baseline than BCAA (P = .04). Area under the curve for creatine kinase was greater in LEU than BCAA (P = .02), whereas BCAA and LBCAA did not differ. Only LEU demonstrated increased soreness during rest and under muscular tension at 24 and 48 h post-ECRE (P < .05). Conclusions: LBCAA failed to afford any advantages over a standard BCAA supplement for postexercise muscle recovery, whereas a LEU supplement was comparatively ineffective.

The protective and therapeutic effects of linalool against doxorubicin-induced cardiotoxicity in Wistar albino rats

The aim of the present study was to determine the protective and therapeutic effects of linalool (LIN) against doxorubicin (DOX)-induced cardiotoxicity in rats histologically and biochemically. In experiments, 64 male Wistar albino rats were randomly divided into eight groups ( n = 8). These groups were control (C) (0.9% saline solution), DOX (20 mg/kg DOX), LIN50 (50 mg/kg LIN), LIN100 (100 mg/kg LIN), DOX + LIN50 (20 mg/kg DOX and 50 mg/kg LIN), DOX + LIN100 (20 mg/kg DOX and 100 mg/kg LIN), LIN50 + DOX (50 mg/kg LIN and 20 mg/kg DOX), and LIN100 + DOX (100 mg/kg LIN and 20 mg/kg DOX). It was determined that necrosis and extensive inflammatory cell infiltration were observed in the DOX group. It was determined that histopathological changes significantly decreased in groups treated with LIN after DOX administration. While the caspase-3 immunostaining was highly evident in DOX group apoptotic cells ( p < 0.001, for all), the intensity of caspase-3 immunostaining in the treatment groups decreased ( p < 0.05). While DOX administration resulted in a significant increase in malondialdehyde (MDA) levels and plasma Creatine kinase (CK) and lactate dehydrogenase (LDH) levels in cardiac tissue when compared to the C groups, it was observed that DOX + LIN administration led to a significant decrease in MDA, plasma CK and LDH levels and a significant increase in glutathione (GSH), superoxide dismutase, and catalase enzyme levels. Finally, it was concluded that DOX led to heavy cardiotoxicity and DOX + LIN administration could remove cardiomyopathy symptoms.

Higher- Versus Lower-Intensity Strength-Training Taper: Effects on Neuromuscular Performance

Purpose: To investigate the effects of strength-training tapers of different intensities but equal volume reductions on neuromuscular performance. Methods: Eleven strength-trained men (21.3 [3.3] y, 92.3 [17.6] kg, relative 1-repetition-maximum deadlift 1.9 [0.2] times bodyweight) completed a crossover study. Specifically, two 4-wk strength-training blocks were followed by a taper week with reduced volume (∼70%) involving either increased (5.9%) or decreased (−8.5%) intensity. Testing occurred pretraining (T1), posttraining (T2), and posttaper (T3). Salivary testosterone and cortisol, plasma creatine kinase, a Daily Analysis of Life Demands in Athletes questionnaire, countermovement jump (CMJ), isometric midthigh pull, and isometric bench press were measured. Results: CMJ height improved significantly over time (P < .001), with significant increases from T1 (38.0 [5.5] cm) to both T2 (39.3 [5.3] cm; P = .010) and T3 (40.0 [5.3] cm; P = .001) and from T2 to T3 (P = .002). CMJ flight time:contraction time increased significantly over time (P = .004), with significant increases from T1 (0.747 [0.162]) to T2 (0.791 [0.163]; P = .012). Isometric midthigh-pull relative peak force improved significantly over time (P = .033), with significant increases from T1 (34.7 [5.0] N/kg) to T2 (35.9 [4.8] N/kg; P = .013). No significant changes were found between tapers. However, the higher-intensity taper produced small effect-size increases at T3 vs T1 for isometric midthigh-pull relative peak force, CMJ height, and flight time:contraction time, while the lower-intensity taper only produced small effect-size improvements at T3 vs T1 for CMJ height. Conclusions: A strength-training taper with volume reductions had a positive effect on power, with a tendency for the higher-intensity taper to produce more favorable changes in strength and power.