Brant Berkstresser

Early Repolarization Pattern in Competitive Athletes Clinical Correlates and the Effects of Exercise Training

Background— Inferior lead early repolarization pattern (ERP) recently has been associated with sudden cardiac death. Although ERP is common among athletes, prevalence, ECG lead distribution, clinical characteristics, and effects of physical training remain uncertain. We sought to examine the nonanterior ERP in competitive athletes. Methods and Results— ERP was assessed in a cross-sectional cohort of collegiate athletes (n=879). The relationship between ERP and cardiac structure were then examined in a longitudinal subgroup (n=146) before and after a 90-day period of exercise training. ERP was defined as J-point elevation ≥0.1 mV in at least 2 leads within a nonanterior territory (inferior [II, III, aVF] or lateral territory [I, aVL, V4-V6]). Nonanterior ERP was present in 25.1% (221/879) of athletes, including the inferior subtype in 3.8% (33/879). Exercise training led to significant increases in the prevalence of ERP and the inferior subtype, but there were no associations between ERP and echocardiographic measures of left ventricular remodeling. In a multivariable model, ERP was associated with black race (odds ratio [OR], 5.84; 95% CI, 3.54 to 9.61; P <0.001), increased QRS voltage (OR, 2.08; 95% CI, 1.71 to 2.52; P <0.001), and slower heart rate (OR, 1.54; 95% CI, 1.26 to 1.87; P <0.001). Conclusions— Nonanterior ERP, including the inferior subtype, is common and has strong clinical associations among competitive athletes. The finding of increased ERP prevalence after intense physical training establishes a strong association between exercise and ERP.Background— Inferior lead early repolarization pattern (ERP) recently has been associated with sudden cardiac death. Although ERP is common among athletes, prevalence, ECG lead distribution, clinical characteristics, and effects of physical training remain uncertain. We sought to examine the nonanterior ERP in competitive athletes. Methods and Results— ERP was assessed in a cross-sectional cohort of collegiate athletes (n=879). The relationship between ERP and cardiac structure were then examined in a longitudinal subgroup (n=146) before and after a 90-day period of exercise training. ERP was defined as J-point elevation ≥0.1 mV in at least 2 leads within a nonanterior territory (inferior [II, III, aVF] or lateral territory [I, aVL, V4-V6]). Nonanterior ERP was present in 25.1% (221/879) of athletes, including the inferior subtype in 3.8% (33/879). Exercise training led to significant increases in the prevalence of ERP and the inferior subtype, but there were no associations between ERP and echocardiographic measures of left ventricular remodeling. In a multivariable model, ERP was associated with black race (odds ratio [OR], 5.84; 95% CI, 3.54 to 9.61; P<0.001), increased QRS voltage (OR, 2.08; 95% CI, 1.71 to 2.52; P<0.001), and slower heart rate (OR, 1.54; 95% CI, 1.26 to 1.87; P<0.001). Conclusions— Nonanterior ERP, including the inferior subtype, is common and has strong clinical associations among competitive athletes. The finding of increased ERP prevalence after intense physical training establishes a strong association between exercise and ERP.

Blood Pressure and Left Ventricular Hypertrophy During American-Style Football Participation

Background— Hypertension, a strong determinant of cardiovascular disease risk, has been documented among elite, professional American-style football (ASF) players. The risk of increased blood pressure (BP) and early adulthood hypertension among the substantially larger population of collegiate ASF athletes is not known. Methods and Results— We conducted a prospective, longitudinal study to examine BP, the incidence of hypertension, and left ventricular remodeling among collegiate ASF athletes. Resting BP and left ventricular structure were assessed before and after a single season of competitive ASF participation in 6 consecutive groups of first-year university athletes (n=113). ASF participation was associated with significant increases in systolic BP (116±8 versus 125±13 mm Hg; P<0.001) and diastolic BP (64±8 mm Hg versus 66±10 mm Hg; P<0.001). At the postseason assessment, the majority of athletes met criteria for Joint National Commission (seventh report) prehypertension (53 of 113, 47%) or stage 1 hypertension (16 of 113, 14%). Among measured characteristics, lineman field position, intraseason weight gain, and family history of hypertension were the strongest independent predictors of postseason BP. Among linemen, there was a significant increase in the prevalence of concentric left ventricular hypertrophy (2 of 64 [3%] versus 20 of 64 [31%]; P<0.001) and change in left ventricular mass correlated with intraseason change in systolic BP (R=0.46, P<0.001). Conclusions— Collegiate ASF athletes may be at risk for clinically relevant increases in BP and the development of hypertension. Enhanced surveillance and carefully selected interventions may represent important opportunities to improve later-life cardiovascular health outcomes in this population.

Regression of "gray zone" exercise-induced concentric left ventricular hypertrophy during prescribed detraining.

To the Editor: Left ventricular hypertrophy (LVH) may develop in response to exercise training. In extreme cases, exercise-induced LVH (EI-LVH) may be difficult to differentiate from clinically relevant conditions such as hypertrophic cardiomyopathy (HCM). A valuable clinical pathway integrating

Exercise-Induced Left Ventricular Remodeling Among Competitive Athletes A Phasic Phenomenon

Background—Contemporary understanding of exercise-induced cardiac remodeling is based on cross-sectional data and relatively short duration longitudinal studies. Temporal progression of exercise-induced cardiac remodeling remains incompletely understood. Methods and Results—A longitudinal repeated-measures study design using 2-dimensional and speckle-tracking echocardiography was used to examine acute augmentation phase (AAP; 90 days) and more extended chronic maintenance phase (39 months) left ventricular (LV) structural and functional adaptations to endurance exercise training among competitive male rowers (n=12; age 18.6±0.5 years). LV mass was within normal limits at baseline (93±9 g/m2), increased after AAP (105±7 g/m2; P=0.001), and further increased after chronic maintenance phase (113±10 g/m2; P<0.001 for comparison to post-AAP). AAP LV hypertrophy was driven by LV dilation (&Dgr;LV end-diastolic volume, 9±3 mL/m2; P=0.004) with stable LV wall thickness (&Dgr;LV wall thickness, 0.3±0.1 mm; P=0.63). In contrast, chronic maintenance phase LV hypertrophy was attributable to LV wall thickening (&Dgr; LV wall thickness, 1.1±0.4 mm; P=0.004) with stable LV chamber volumes (&Dgr;LV end-diastolic volume, 1±1 mL/m2; P=0.48). Early diastolic peak tissue velocity increased during AAP (−11.7±1.9 versus −13.6±1.3 cm/s; P<0.001) and remained similarly increased after chronic maintenance phase. Conclusions—In a small sample of competitive endurance athletes, exercise-induced cardiac remodeling follows a phasic response with increases in LV chamber size, early diastolic function, and systolic twist in an acute augmentation phase of exercise training. This is followed by a chronic phase of adaptation characterized by increasing wall thickness and regression in LV twist. Training duration is a determinant of exercise-induced cardiac remodeling and has implications for the assessment of myocardial structure and function in athletes.

Impact of American-Style Football Participation on Vascular Function

Although hypertension is common in American-style football (ASF) players, the presence of concomitant vascular dysfunction has not been previously characterized. We sought to examine the impact of ASF participation on arterial stiffness and to compare metrics of arterial function between collegiate ASF participants and nonathletic collegiate controls. Newly matriculated collegiate athletes were studied longitudinally during a single season of ASF participation and were then compared with healthy undergraduate controls. Arterial stiffness was characterized using applanation tonometry (SphygmoCor). ASF participants (n = 32, 18.4 ± 0.5 years) were evenly comprised of Caucasians (n = 14, 44%) and African-Americans (n = 18, 56%). A single season of ASF participation led to an increase in central aortic pulse pressure (27 ± 4 vs 34 ± 8 mm Hg, p <0.001). Relative to controls (n = 47), pulse wave velocity was increased in ASF participants (5.6 ± 0.7 vs 6.2 ± 0.9 m/s, p = 0.002). After adjusting for height, weight, body mass index, systolic blood pressure, and diastolic blood pressure, ASF participation was independently predictive of increased pulse wave velocity (β = 0.33, p = 0.04). In conclusion, ASF participation leads to changes in central hemodynamics and increased arterial stiffness.

Full-contact practice and injuries in college football

Background: Despite recent restrictions being placed on practice in college football, there are little data to correlate such changes with injuries. Hypothesis: Football injuries will correlate with a team’s exposure to full-contact practice, total practice, and total games. Study Design: Descriptive epidemiological study. Methods: All injuries and athlete injury exposures (AE × Min = athletes exposed × activity duration in minutes) were recorded for an intercollegiate football team over 4 consecutive fall seasons. Weekly injuries and injury rates (injuries per athletic injury exposure) were correlated with the weekly exposures to full-contact practices, total practices, formal scrimmages, and games. Results: The preseason practice injury rate was over twice the in-season practice injury rate (P < 0.001). For preseason, injury exposures were higher for full-contact practice (P = 0.0166), total practices (P = 0.015), and scrimmages/games (P = 0.034) compared with in-season. Preseason and in-season practice injuries correlated with exposure to full-contact practice combined with scrimmages for preseason (P < 0.008) and full-contact practice combined with games for in-season (P = 0.0325). The game injury rate was over 6 times greater than the practice injury rate (P < 0.0001). Concussions constituted 14.5% of all injuries, and the incidence of concussions correlated with the incidence of all injuries (P = 0.0001). Strength training did not correlate with injuries. Conclusion: Decreased exposure to full-contact practice may decrease the incidence of practice injuries and practice concussions. However, the game injury rate was over 6 times greater than the practice injury rate and had an inverse correlation with full-contact practice.

The utility of instrumented dual-task gait and tablet-based neurocognitive measurements after concussion

OBJECTIVES Quantitative and non-invasive measurements acquired by neurocognitive or gait evaluations are useful concussion management components. Emerging technology has allowed for the development of portable and objective tests which may be potentially useful across many settings where evaluations take place. Our aim was to examine the association between instrumented dual-task gait and tablet-based neurocognitive outcome variables with an acute concussion. DESIGN A total of 59 collegiate athletes were identified and tested within 5days of concussion (n=18, 50% female, 20±1years of age) or as a part of a baseline examination (n=41, 29% female, 19±1years of age). METHODS Participants completed an instrumented dual-task gait evaluation and a tablet-based neurocognitive evaluation. Outcome variables were compared with t-tests, and a multivariable logistic regression model was constructed to identify the association between the presence of a concussion and test performance. RESULTS Compared with controls, participants with concussion reported significantly more severe symptoms (PCSS=19.1±15.2 vs. 4.1±6.3; p<0.001), walked significantly slower during dual-task conditions (87.7±10.4cm/s vs. 98.1±15.4cm/s; p=0.01), and responded with significantly slower simple reaction times (305.2±32.4ms vs. 275.4±22.1ms; p<0.001). After adjusting for the effect of potential confounding variables, these three variables (more severe symptoms, slower walking speed, and slower reaction time) remained independently associated with concussion (adjusted odds ratios=1.181, 0.916, and 1.043, respectively). CONCLUSIONS Relatively simple quantitative measurements of dual-task gait and reaction time may be useful and portable clinical tests in the multifaceted assessment of concussion.

Self-reported sleep duration affects tandem gait, but not steady-state gait outcomes among healthy collegiate athletes

BACKGROUND Sleep deficits are associated with motor and cognitive function deficits, even in the absence of a recent concussion. RESEARCH QUESTION Does the amount of self-reported sleep prior to pre-season concussion testing affect single-task and dual-task instrumented steady-state gait and timed tandem gait test performance? METHODS One hundred and fourteen healthy collegiate athletes (mean age 18.8 ± 0.7 years; 60% female) reported the amount of sleep they received during the prior night and completed a timed tandem gait test and an instrumented assessment of steady-state gait in both single-task and dual-task conditions. Outcome variables included spatio-temporal gait parameters during steady-state gait, best and mean tandem gait times, and cognitive test accuracy. RESULTS Participants who reported sleeping <7 h of sleep during the night prior to testing (n = 62) had significantly longer tandem gait times in single-task and dual-task conditions (11.1 ± 2.2 vs. 10.1 ± 2.0 s and 14.5 ± 4.3 vs. 12.3 ± 2.6 s, respectively; p = .009) compared to those who reported sleeping ≥7 h (n = 52). No significant differences between groups were observed for spatio-temporal steady-state gait variables or for cognitive test accuracy. SIGNIFICANCE Self-reported sleep duration may be associated with baseline testing tandem gait performance. Thus, as sleep can play a role in motor abilities, clinicians may consider interpreting tandem gait performance in light of sleep duration during the night prior to testing.

Myocardial Metabolism in Endurance Exercise-Induced Left Ventricular Hypertrophy

Pathologic forms of left ventricular hypertrophy (LVH) are associated with impaired myocardial metabolic efficiency (MME), the ratio of myocardial work to oxygen consumption (MVO2), which may serve as a key mechanistic link between LVH and the development of heart failure syndromes [(1,2)][1]. At

Exercise-Induced Left Ventricular Remodeling Among Competitive AthletesCLINICAL PERSPECTIVE

Background—Contemporary understanding of exercise-induced cardiac remodeling is based on cross-sectional data and relatively short duration longitudinal studies. Temporal progression of exercise-induced cardiac remodeling remains incompletely understood. Methods and Results—A longitudinal repeated-measures study design using 2-dimensional and speckle-tracking echocardiography was used to examine acute augmentation phase (AAP; 90 days) and more extended chronic maintenance phase (39 months) left ventricular (LV) structural and functional adaptations to endurance exercise training among competitive male rowers (n=12; age 18.6±0.5 years). LV mass was within normal limits at baseline (93±9 g/m2), increased after AAP (105±7 g/m2; P=0.001), and further increased after chronic maintenance phase (113±10 g/m2; P<0.001 for comparison to post-AAP). AAP LV hypertrophy was driven by LV dilation (&Dgr;LV end-diastolic volume, 9±3 mL/m2; P=0.004) with stable LV wall thickness (&Dgr;LV wall thickness, 0.3±0.1 mm; P=0.63). In contrast, chronic maintenance phase LV hypertrophy was attributable to LV wall thickening (&Dgr; LV wall thickness, 1.1±0.4 mm; P=0.004) with stable LV chamber volumes (&Dgr;LV end-diastolic volume, 1±1 mL/m2; P=0.48). Early diastolic peak tissue velocity increased during AAP (−11.7±1.9 versus −13.6±1.3 cm/s; P<0.001) and remained similarly increased after chronic maintenance phase. Conclusions—In a small sample of competitive endurance athletes, exercise-induced cardiac remodeling follows a phasic response with increases in LV chamber size, early diastolic function, and systolic twist in an acute augmentation phase of exercise training. This is followed by a chronic phase of adaptation characterized by increasing wall thickness and regression in LV twist. Training duration is a determinant of exercise-induced cardiac remodeling and has implications for the assessment of myocardial structure and function in athletes.