Cardiac function and autonomic cardiac function during a multi-stage cycling event: a brief report.

Introduction: Prolonged and repeated exercise performed during an ultra-endurance event can induce general and cardiac fatigue known as exercise-induced cardiac fatigue. Our objective was to find a possible correlation between the cardiac function and the autonomic cardiac function. Methods: During a multistage ultra-endurance event, a female well-trained cyclist underwent daily rest echocardiography and heart rate variability measurements to assess the cardiac function and the cardiac autonomic function. Results: The athlete completed 3,345 km at 65% of her maximum heart rate and 39% of her maximum aerobic power. A progressive improvement of the systolic function for both the left ventricle and the right ventricle was observed during the event. Discussion: Alterations were observed on the cardiac autonomic function with an imbalance between sympathetic and parasympathetic, but there was no sign of a significant correlation between the cardiac function and the autonomic cardiac function and no signs of cardiac fatigue either. Further analysis should be performed on a larger sample to confirm the obtained results.

Impact of long-lasting moderate-intensity stage cycling event on cardiac function in young female athletes: A case study.

PURPOSE: Effects of intense and/or prolonged exercise have been studied extensively in male athletes. Nevertheless, data are scare on the effect of long duration events on cardiac function in female athletes. Our aim was to investigate the effect of a long-lasting moderate-intensity stage cycling event on cardiac function of young female athletes. METHODS: Seven well-trained female cyclists were included. They completed a cycling event of 3529 km on 23 days. All underwent an echocardiography on 6 time-points (baseline and at the arrival of day (D) 3, 7, 12, 13 and 23). Cardiac function was assessed by conventional echocardiography, tissue Doppler imaging and speckle tracking techniques. Daily exercise load was determined by heart rate (HR), power output and rate of perceived exertion data (RPE, Borg scale). RESULTS: All stages were mainly done at moderate intensity (average HR: 65% of maximal, average aerobic power output: 36% of maximal, average RPE: 4). Resting HR measured at the time of echocardiography did not vary during the event. Resting cardiac dimensions did not significantly change during the 23 days of cycling. No significant modification of cardiac function, whatever the studied cavity, were observed all along the event. CONCLUSION: The results suggest that, in the context of our case study, the long-lasting moderate-intensity stage cycling event was not associated with cardiac function alteration. Nevertheless, we must be careful in interpreting them due to the limits of an underpowered study.

Cardiac Events in World-Class Athletes: An Internet-Based Study.

PURPOSE: This study aimed at assessing the prevalence of adverse cardiac events, as identified in the media, in world-class athletes according to their sex and sports discipline. METHODS: All female and male athletes from 30 individual Olympic sports who ranked in the international yearly top 10 between 2006 and 2018 were included. The name of each of them was associated in a Google search with selected key terms related to heart disease and/or acute cardiac events after their inclusion date. Global and sex-specific adverse cardiac event hazard function λ were calculated for each sport. Global and sex-specific prevalences of cardiac events were calculated, then compared (Fisher's exact test) between all sports. RESULTS: From the 2471 athletes included, 15 cases of cardiac events (prevalence of 0.61%) were reported; 2 sudden cardiac deaths (0.08%) occurred in male athletes. The other events were related to arrhythmic events ( n = 13), mainly supraventricular arrhythmias ( n = 9). All surviving athletes were able to continue their career, mostly after ablation procedure. Male endurance athletes accounted for seven events, among which three events occurred among short-distance triathletes. Events among women were comparatively rare ( n = 4), and all were observed among short-distance triathletes. CONCLUSIONS: A relatively unexpected high prevalence of cardiac events in endurance elite athletes was observed as compared with other sports, mainly, in short-distance male and female triathletes. This raises the question of particular cardiovascular constraints in this discipline and underlines the urge of international longitudinal follow-up studies in these kinds of athletes.

Exercise-Induced Cardiac Fatigue in Soldiers Assessed by Echocardiography.

Background: Echocardiographic signs of exercise-induced cardiac fatigue (EICF) have been described after strenuous endurance exercise. Nevertheless, few data are available on the effects of repeated strenuous exercise, especially when associated with other constraints as sleep deprivation or mental stress which occur during military selection boot camps. Furthermore, we aimed to study the influence of experience and training level on potential EICF signs. Methods: Two groups of trained soldiers were included, elite soldiers from the French Navy Special Forces (elite; n = 20) and non-elite officer cadets from a French military academy (non-elite; n = 38). All underwent echocardiography before and immediately after exposure to several days of uninterrupted intense exercise during their selection boot camps. Changes in myocardial morphology and function of the 4 cardiac chambers were assessed. Results: Exercise-induced decrease in right and left atrial and ventricular functions were demonstrated with 2D-strain parameters in both groups. Indeed, both atrial reservoir strain, RV and LV longitudinal strain and LV global constructive work were altered. Increase in LV mechanical dispersion assessed by 2D-strain and alteration of conventional parameters of diastolic function (increase in E/e' and decrease in e') were solely observed in the non-elite group. Conventional parameters of LV and RV systolic function (LVEF, RVFAC, TAPSE, s mitral, and tricuspid waves) were not modified. Conclusions: Alterations of myocardial functions are observed in soldiers after uninterrupted prolonged intense exercise performed during selection boot camps. These alterations occur both in elite and non-elite soldiers. 2D-strain is more sensitive to detect EICF than conventional echocardiographic parameters.