Adaptation of Left Ventricular Twist Mechanics in Exercise-Trained Children Is Only Evident after the Adolescent Growth Spurt.

The extent of structural cardiac remodeling in response to endurance training is maturity dependent. In adults, this structural adaptation is often associated with the adaptation of left ventricular (LV) twist mechanics. For example, an increase in LV twist often follows an expansion in end-diastolic volume, whereas a reduction in twist may follow a thickening of the LV walls. While structural cardiac remodeling has been shown to be more prominent post-peak height velocity (PHV), it remains to be determined how this maturation-dependent structural remodeling influences LV twist. Therefore, we aimed to (1) compare LV twist mechanics between trained and untrained children pre- and post-PHV and (2) investigate how LV structural variables relate to LV twist mechanics pre- and post-PHV. Left ventricular function and morphology were assessed (echocardiography) in endurance-trained and untrained boys (n = 38 and n = 28, respectively) and girls (n = 39 and n = 34, respectively). Participants were categorized as either pre- or post-PHV using maturity offset to estimate somatic maturation. Pre-PHV, there were no differences in LV twist or torsion between trained and untrained boys (twist: P = .630; torsion: P = .382) or girls (twist: P = .502; torsion: P = .316), and LV twist mechanics were not related with any LV structural variables (P > .05). Post-PHV, LV twist was lower in trained versus untrained boys (P = .004), with torsion lower in trained groups, irrespective of sex (boys: P < .001; girls: P = .017). Moreover, LV torsion was inversely related to LV mass (boys: r = -0.55, P = .001; girls: r = -0.46, P = .003) and end-diastolic volume (boys: r = -0.64, P < .001; girls: r = -0.36, P = .025) in both sexes. A difference in LV twist mechanics between endurance-trained and untrained cohorts is only apparent post-PHV, where structural and functional remodeling were related

Physicians approach shared decision-making for sports eligibility decisions heterogeneously.

There is limited data regarding how clinicians operationalize shared decision-making (SDM) with athletes with cardiovascular diagnoses. This study was designed to explore sports cardiologists' conceptions of SDM and approaches to sports eligibility decisions. 20 sports cardiologists were interviewed by telephone or video conference from October 2022 to May 2023. Qualitative descriptive analysis was conducted with the transcripts. All participants endorsed SDM for eligibility decisions, however, SDM was defined and operationalized heterogeneously. Only 6 participants specifically referenced eliciting patient preferences during SDM. Participants described variable roles for the physician in SDM and variable views on athletes' understanding, perception, and tolerance of risk. Participants thresholds for prohibitive annual risk of sudden cardiac death ranged from <1 % to >10 %. These findings reinforce the general acceptance of SDM for sports eligibility decisions and highlight the need to better understand this process and identify the most effective approach for operationalization

Priming cardiac function with voluntary respiratory maneuvers and effect on early exercise oxygen uptake.

Oxygen uptake (V̇o <sub>2</sub> ) at exercise onset is determined in part by acceleration of pulmonary blood flow ([Formula: see text]). Impairments in the [Formula: see text] response can decrease exercise tolerance. Prior research has shown that voluntary respiratory maneuvers can augment venous return, but the corollary impacts on cardiac function, [Formula: see text] and early-exercise V̇o <sub>2</sub> remain uncertain. We examined 1) the cardiovascular effects of three distinct respiratory maneuvers (abdominal, AB; rib cage, RC; and deep breathing, DB) under resting conditions in healthy subjects (Protocol 1, n = 13), and 2) the impact of pre-exercise DB on pulmonary O <sub>2</sub> transfer during initiation of moderate-intensity exercise (Protocol 2, n = 8). In Protocol 1, echocardiographic analysis showed increased right ventricular (RV) cardiac output and left ventricular (LV) cardiac output (RVCO and LVCO, respectively), following AB (by +23 ± 13 and +18 ± 15%, respectively, P < 0.05), RC (+23 ± 16; +14 ± 15%, P < 0.05), and DB (+27 ± 21; +23 ± 14%, P < 0.05). In Protocol 2, DB performed for 12 breaths produced a pre-exercise increase in V̇o <sub>2</sub> (+801 ± 254 mL·min <sup>-1</sup> over ∼6 s), presumably from increased [Formula: see text], followed by a reduction in pulmonary O <sub>2</sub> transfer during early phase exercise (first 20 s) compared with the control condition (149 ± 51 vs. 233 ± 65 mL, P < 0.05). We conclude that 1) respiratory maneuvers enhance RVCO and LVCO in healthy subjects under resting conditions, 2) AB, RC, and DB have similar effects on RVCO and LVCO, and 3) DB can increase [Formula: see text] before exercise onset. These findings suggest that pre-exercise respiratory maneuvers may represent a promising strategy to prime V̇o <sub>2</sub> kinetics and thereby to potentially improve exercise tolerance in patients with impaired cardiac function.NEW & NOTEWORTHY We demonstrate that different breathing maneuvers can augment both right and left-sided cardiac output in healthy subjects. These maneuvers, when performed immediately before exercise, result in a pre-exercise "cardiodynamic" increase in oxygen uptake (V̇o <sub>2</sub> ) associated with a subsequent reduction in the "cardiodynamic" V̇o <sub>2</sub> normally seen during early exercise. We conclude that pre-exercise breathing maneuvers are a plausible tool worthy of additional study to prime V̇o <sub>2</sub> kinetics and improve exercise tolerance in patients with cardiovascular disease

Bases de la physiologie de l’exercice : du principe de Fick au cœur d’athlète [Basics of exercise physiology: from Fick principle to the athlete's heart]

Physical activity is undeniably associated with numerous health benefits. However, performance of high intensity and/or high-volume exercise poses a significant physiological challenge to the cardiovascular and respiratory systems, which must undergo several adaptations to meet the increased metabolic demands of the organism. Repeated and prolonged exposure to training leads to long-term cardiac remodeling aimed at optimizing the efficiency of the work performed by the heart during exertion. This article discusses some of the fundamental mechanisms of cardiovascular physiology during exercise including adaptive responses to acute bouts of exercise and longer term structural and functional characteristics of the athlete's heart

Medical Conditions in Former Professional American-Style Football Players Are Associated With Self-Reported Clinical Features of Traumatic Encephalopathy Syndrome.

Consensus criteria for traumatic encephalopathy syndrome (TES) specify that at least one core clinical feature of cognitive impairment (CI; e.g., difficulties with memory, executive function) or neurobehavioral dysregulation (ND; e.g., explosiveness, rage, and mood lability) be present and not fully accounted for by other health disorders. Associations between self-reported symptoms that mirror the core clinical features of TES-and how they may be related to concomitant medical conditions-remain unclear. The purpose of this study was to evaluate the association of medical conditions and football exposures with TES clinical features (CI <sup>+/-</sup> , ND <sup>+/-</sup> ) in 1741 former professional American-style football (ASF) players (age, 57.7 ± 13.9 years; professional seasons, 6.6 ± 3.9 years). Demographics (age, race/ethnicity, current body mass index, age of first football exposure, use of performance-enhancing drugs, position played, and past concussion symptoms), self-reported medical conditions (anxiety, depression, attention-deficit hyperactivity disorder [ADHD], sleep apnea, headache, stroke, hypertension, heart disease, high cholesterol, erectile dysfunction, and low testosterone) were collected. Of 1741 participants, 7.4% were CI <sup>+</sup> and/or ND <sup>+</sup> (n = 129). Participants who were CI <sup>+</sup> or ND <sup>+</sup> were more likely to report one or more coexisting medical conditions than participants who did not report CI or ND (odds ratio [OR] = 2.04; 95% confidence interval: 1.25-3.47; p = 0.003). Separate general linear models for each medical condition that adjusted for demographics and football-related factors identified significant associations between ADHD, diabetes, erectile dysfunction, headaches, sleep apnea, anxiety, and low testosterone and CI <sup>+</sup> and/or ND <sup>+</sup> (ORs = 1.8-6.0). Chi-square automatic interaction detection (CHAID) multi-variable decision tree models that incorporated medical conditions and football exposures accurately differentiated former players meeting either CI or ND clinical criteria from those meeting none (accuracy = 91.2-96.6%). CHAID identified combinations of depression, headache, sleep apnea, ADHD, and upper quartiles of concussion symptom history as most predictive of CI <sup>+</sup> and/or ND <sup>+</sup> status. CI <sup>+</sup> and/or ND <sup>+</sup> players were more likely to report medical conditions known to cause cognitive symptoms. Concussion exposure and medical conditions significantly increased the likelihood that a former ASF player would demonstrate cognitive or neurobehavioral dysfunction. Clinicians engaged with this population should consider whether treatable coexisting condition(s) could account for some portion of the clinical picture associated with TES presentation

Consumer Wearable Health and Fitness Technology in Cardiovascular Medicine: JACC State-of-the-Art Review.

The use of consumer wearable devices (CWDs) to track health and fitness has rapidly expanded over recent years because of advances in technology. The general population now has the capability to continuously track vital signs, exercise output, and advanced health metrics. Although understanding of basic health metrics may be intuitive (eg, peak heart rate), more complex metrics are derived from proprietary algorithms, differ among device manufacturers, and may not historically be common in clinical practice (eg, peak V˙O <sub>2</sub> , exercise recovery scores). With the massive expansion of data collected at an individual patient level, careful interpretation is imperative. In this review, we critically analyze common health metrics provided by CWDs, describe common pitfalls in CWD interpretation, provide recommendations for the interpretation of abnormal results, present the utility of CWDs in exercise prescription, examine health disparities and inequities in CWD use and development, and present future directions for research and development