Resting and post exercise arterial–ventricular coupling in endurance-trained men and women

Effects of a Transoceanic Rowing Challenge on Cardiorespiratory Function and Muscle Fitness

Ultra-endurance sports and exercise events are becoming increasingly popular for older age groups. We aimed to evaluate changes in cardiac function and physical fitness in males aged 50-60 years who completed a 50-day transoceanic rowing challenge. This case account of four self-selected males included electro- and echo-cardiography (ECG, echo), cardiorespiratory and muscular fitness measures recorded nine months prior to and three weeks after a transatlantic team-rowing challenge. No clinically significant changes to myocardial function were found over the course of the study. The training and race created expected functional changes to left ventricular and atrial function; the former associated with training, the latter likely due to dehydration, both resolving towards baseline within three weeks post-event. From race-start to finish all rowers lost 8.4-15.6 kg of body mass. Absolute cardiorespiratory power and muscular strength were lower three weeks post-race compared to pre-race, but cardiorespiratory exercise economy improved in this same period. A structured program of moderate-vigorous aerobic endurance and muscular training for>6 months, followed by 50-days of transoceanic rowing in older males proved not to cause any observable acute or potential long-term risks to cardiovascular health. Pre-event screening, fitness testing, and appropriate training is recommended, especially in older participants where age itself is an increasingly significant risk factor.

Effect of live-fire training on ventricular-vascular coupling

INTRODUCTION

Cardiovascular events are a leading cause of firefighter duty-related death, with the greatest risk occurring during or shortly after fire suppression activity. Increased cardiovascular risk potentially manifests from detrimental changes in ventricular function, vascular load, and their interaction, described as ventricular-vascular coupling.

PURPOSE

To determine the effect of live-fire training on ventricular-vascular coupling.

METHODS

Sixty-eight male (28 [Formula: see text] 7 years, 26.9 [Formula: see text] 3.9 kg/m²) and fifteen female (36 [Formula: see text] 8 years, 24.3 [Formula: see text] 3.9 kg/m²) firefighters completed hemodynamic and cardiac measures before and after 3 h of intermittent live-fire training. Left ventricular function was assessed as ejection fraction (EF) and ventricular elastance (E_LV: end systolic pressure [ESP]/end systolic volume) via echocardiography and applanation tonometry-estimated ESP. Vascular load was assessed as arterial elastance (E_A: ESP/stroke volume [SV]). Ventricular-vascular coupling (VVC) was quantified as the ratio of E_A to E_LV and indexed to body surface area (E_AI, E_LVI).

RESULTS

Following firefighting EF decreased (p < 0.01) with no change in E_LVI (p = 0.34). SV decreased (p < 0.01) with no change in ESP (p = 0.09), driving a significant increase in E_AI (p < 0.01). These changes resulted in a significant increase in the VVC ratio (p < 0.01).

CONCLUSION

The findings suggest that firefighting does not alter ventricular elastance but increases arterial elastance in healthy firefighters, resulting in a mismatch between ventricular and vascular systems. This increase in ventricular-vascular coupling ratio and concomitant reduction in ventricular systolic function may contribute to increased cardiovascular risk following live firefighting.

Stroke Work Damping Ratio is Increased in Trained Athletes

INTRODUCTION

Athletes training is often associated with morphological changes in the heart. In this sense, the ventricular pressure-volume (PV) relation provides a complete characterization of cardiac pump performance. Regarding the arterial system (AS), arterial wall viscosity is a source of energy dissipation, that takes place during mechanical transduction. Left ventricular stroke work (SW) constitutes the useful fraction of ventricular energy that is delivered to the AS.

OBJECTIVE

Left ventricular PV-loops were evaluated in terms of AS viscous property, by means of the interaction of two SW components (Stroke Work Damping Ratio, SWDR), both in untrained and trained subjects.

MATERIAL AND METHODS

Fourteen healthy individuals (seven trained) were noninvasively evaluated in terms of echocardiographic and aortic pressure measurements.

RESULTS

SWDR was observed to be increased in trained subjects.

CONCLUSION

SWDR was evaluated in trained individuals, being increased in comparison with the non-trained group. This effect is a consequence of a significant increase of SWD, which could be related with the viscous mechanical property of AS.

Sex-Specific Ventricular and Vascular Adaptations to Exercise

Increasing data suggest that there are sex differences in ventricular and vascular adaptations to aerobic (endurance) exercise, which may be attributed to different physical and physiological features in men and women. Despite that cardiovascular control during acute exercise at the same relative work rate (e.g., the percentage of peak oxygen uptake) appears to be similar between the sexes, women have blunted responses or adaptations to prolonged (e.g., ≥1 year) exercise training compared with men. Currently, there is little evidence to suggest that exercise-induced vascular adaptations are different between men and women. Furthermore, sex differences in skeletal muscle adaptations to exercise, and how this influences cardiovascular function, remain unclear. Identifying potential differences and the mechanisms behind such exercise-induced adaptations is important for the optimization of exercise interventions between men and women across the life span.

Improved arterial-ventricular coupling in metabolic syndrome after exercise training: a pilot study

PURPOSE

The metabolic syndrome (MetS) is associated with threefold increased risk of cardiovascular (CV) morbidity and mortality, which is partly due to a blunted CV reserve capacity, reflected by a reduced peak exercise left ventricular (LV) contractility and aerobic capacity and a blunted peak arterial-ventricular coupling. To date, no study has examined whether aerobic exercise training in MetS can reverse peak exercise CV dysfunction. Furthermore, examining how exercise training alters CV function in a group of individuals with MetS before the development of diabetes and/or overt CV disease can provide insights into whether some of the pathophysiological CV changes can be delayed/reversed, lowering their CV risk. The objective of this study was to examine the effects of 8 wk of aerobic exercise training in individuals with MetS on resting and peak exercise CV function.

METHODS

Twenty participants with MetS underwent either 8 wk of aerobic exercise training (MetS-ExT, n = 10) or remained sedentary (MetS-NonT, n = 10) during this period. Resting and peak exercise CV function was characterized using Doppler echocardiography and gas exchange.

RESULTS

Exercise training did not alter resting LV diastolic or systolic function and arterial-ventricular coupling in MetS. In contrast, at peak exercise, an increase in LV contractility (40%, P < 0.01), cardiac output (28%, P < 0.05), and aerobic capacity (20%, P < 0.01), but a reduction in vascular resistance (30%, P < 0.05) and arterial-ventricular coupling (27%, P < 0.01), were noted in the MetS-ExT but not in the MetS-NonT group. Furthermore, an improvement in lifetime risk score was also noted in the MetS-ExT group.

CONCLUSIONS

These findings have clinical importance because they provide insight that some of the pathophysiological changes associated with MetS can be improved and can lower the risk of CV disease.

Gender differences in myocardial function and arterio-ventricular coupling in response to maximal exercise in adolescent floor-ball players

BACKGROUND

The hemodynamic and cardiac responses to exercise have been widely investigated in adults. However, little is known regarding myocardial performance in response to a short bout of maximal exercise in adolescents. We therefore sought to study alterations in myocardial function and investigate sex-influences in young athletes after maximal cardiopulmonary testing.

METHODS

51 adolescent (13-19 years old) floor-ball players (24 females) were recruited. All subjects underwent a maximal exercise test to determine maximal oxygen uptake (VO2max) and cardiac output. Cardiac performance was investigated using conventional and tissue velocity imaging, as well as 2D strain echocardiography before and 30 minutes following exercise. Arterio-ventricular coupling was evaluated by means of single beat ventricular elastance and arterial elastance.

RESULTS

Compared to baseline the early diastolic myocardial velocity (E'LV) at the basal left ventricular (LV) segments declined significantly (females: E'LV: 14.7 +/- 2.6 to 13.6 +/- 2.9 cm/s; males: 15.2 +/- 2.2 to 13.9 +/- 2.3 cm/s, p < 0.001 for both). Similarly, 2D strain decreased significantly following exercise (2D strain LV: from 21.5 +/- 2.4 to 20.2 +/- 2.7% in females, and from 20 +/- 1 to 17.9 +/- 1.5% in males, p < 0.05 for both). However, there were no significant changes in LV contractility estimated by elastance in either sex following exercise (p > 0.05). Arterial elastance) Ea) at baseline was identified as the only predictor of VO2max in males (r = 0.76, p < 0.001) but not in females (p > 0.05).

CONCLUSIONS

The present study demonstrates that vigorous exercise of short duration results in a significant decrease of longitudinal myocardial motion in both sexes. However, in view of unaltered end systolic LV elastance (Ees), these reductions most probably reflect changes in the loading conditions and not an attenuation of myocardial function per se. Importantly, we show that arterial load at rest acts as a strong predictor of VO2max in males but not in female subjects.