The "athlete's heart" features in amateur male marathon runners

The athletes heart-from acute stimulus to chronic adaptation

INTRODUCTION

The complex phenomenon of the athlete's heart (AH) describes the chronic physiological structural and functional adaptation secondary to repeated exposure of an acute exercise stimulus.

SOURCES OF DATA

This narrative review is based on published evidence.

AREAS OF AGREEMENT

Highly trained athletic individuals frequently display cardiac parameters which are suggestive of an AH and can exceed the traditional 'normal' limits.

AREA OF CONTROVERSY

The physiological processes underpinning the extent of cardiac adaption and how this is closely linked to exercise type, but also sex, ethnicity, and body size.

GROWING POINTS

Since its seminal description by Morganroth and colleagues in 1975, our understanding of the AH has evolved in tandem with improvements in cardiac imaging techniques alongside the exploration of more diverse athletic populations. This narrative review aims to provide a balanced discussion of the multi-factorial nature of structure and function of the AH with specific reference to the unique physiological exercise stimuli.

AREAS TIMELY FOR DEVELOPING RESEARCH

Despite great interest in cardiac adaptations across a broad spectrum of athletic populations, future research designs should consider the use of new and novel imaging techniques to enhance our understanding of the acute cardiovascular responses which ultimately mediates such adaptations, especially in athletic populations underrepresented in the literature.

Sex differences in the associations between right heart structure and peak exercise capacity parameters in amateur cyclists

Introduction: Right heart changes and their association with exercise capacity, including sex differences, are still being investigated. We analysed right heart structure and its relationship with exercise capacity parameters in amateur cyclists. Materials and methods: A cross-sectional study involving 215 consecutive adult amateur cyclists, who underwent resting transthoracic echocardiography and a cardiopulmonary exercise test (CPET) to exhaustion was performed. Results: The median age of participants was 29 years (IQR 24-37), 71% of them were men. The mean training time was 6 h/week, and 90% participated in vigorous or moderate physical activity. Men had larger right ventricular diameters (basal - RVD1, mid-cavity - RVD2 and longitudinal - RVD3) compared to women (40.9 vs. 37.6 mm, p = 0.0005, 28.7 vs. 26.3 mm, p = 0.03, 92.2 vs. 81.9 mm, p < 0.0001). Indexing for body surface area revealed comparable right atrial volume (RAVI) between sexes (24.1 vs. 22.7 mL/m2). Men achieved higher peak exercise capacity parameters [O2 pulse, oxygen consumption (VO2) and workload] in CPET. Multivariate linear regression models revealed a positive association between peak VO2, workload and O2 pulse with RAVI in women but not with RVD1 or RVD3. Conversely, these parameters showed a positive association with RVD3 and RVD1 but not with RAVI in men. Conclusion: Sex differences exist in the relationship between right heart structural parameters and peak exercise capacity descriptors in amateur cyclists. Better exercise capacity during CPET to exhaustion is associated with greater RAVI in women but a greater RVD1 and RVD3 in men. These findings suggest different mechanisms of right heart adaptation to training in men and women.

The athlete's heart: insights from echocardiography

The manifestations of the athlete's heart can create diagnostic challenges during an echocardiographic assessment. The classifications of the morphological and functional changes induced by sport participation are often beyond 'normal limits' making it imperative to identify any overlap between pathology and normal physiology. The phenotype of the athlete's heart is not exclusive to one chamber or function. Therefore, in this narrative review, we consider the effects of sporting discipline and training volume on the holistic athlete's heart, as well as demographic factors including ethnicity, body size, sex, and age.

Reduced myocardial strain of interventricular septum among male amateur marathon runners: a cardiac magnetic resonance study

OBJECTIVES

To analyze the long-term effect of multiple marathons on cardiac structure and function in amateur marathon runners compared with healthy controls.

DESIGN

Cross-sectional study using male amateur marathon runners (n = 32) and age-matched cohort of male healthy controls (n = 12).

METHODS

A total of 32 male amateur marathon runners (age 44 ± 7 years) and 12 male healthy controls (age 42 ± 8 years) underwent cardiac magnetic resonance (CMR). The relevant parameters of cardiac structure and function were studied employing feature-tracking strain analysis.

RESULTS

Amateur marathon runners showed lower heart rates, body mass index and body surface area. The left ventricular (LV) mass index, LV end-diastolic volume index and right ventricular end-systolic volume index were significantly higher in amateur marathon runners compared with healthy controls. Furthermore, walls of interventricular septum (IVS) in amateur marathon runners were thicker than healthy controls. There was no significant difference between two groups in the global myocardial strain (MS) in LV. However, the segmental radial and circumferential strains of the LV were lower in amateur marathon runners compared to healthy controls, specifically in the 8th and 9th segments. Finally, we also found as the total running intensity increased, so did global longitudinal strain.

CONCLUSIONS

We reported higher wall thickness and lower regional radial and circumferential strain in the IVS region in amateur marathon runners, suggesting that prolonged and high-intensity exercise may cause cardiac remodeling. Further studies are needed to investigate whether this is an adaptive or maladaptive change in amateur marathon runners.

Assessment of right ventricular structure and systolic function in amateur marathon runners using three-dimensional speckle tracking echocardiography

Prolonged high-intensity endurance exercise has been reported to have adverse effects on the heart, which are further correlated with exercise dose. However, its effect on the right ventricle (RV) of amateur runners is unknown. This study aimed was to evaluate the early right ventricular structure and systolic function of amateur marathon runners by three-dimensional speckle tracking echocardiography (3D-STE), and to further analyze the correlation between relevant parameters and the amount of training. A total of 30 amateur marathon runners (marathon group) and 27 healthy volunteers (control group) were enrolled. Conventional echocardiography combined with 3D-STE was performed in all subjects, and the marathon group was screened by echocardiography a week before a marathon (V1), within 1 h post-marathon (V2), and 4 days post-marathon (V3). RV global longitudinal strain (GLS) and RV end-diastolic volume (EDV) increased significantly in the marathon group compared to the control group (P < 0.05). RV GLS was significantly decreased in the marathon group within 1 h post-marathon (V1: - 26.2 ± 2.5% vs V2: - 23.0 ± 1.6% vs V3: - 25.6 ± 2.6%, P < 0.001). However, there was no significant difference in RV ejection fraction (RVEF) (P > 0.05). The results of the correlation analysis showed that RV EDV and RV end-systolic volume (ESV) were positively correlated with the average training volume (P < 0.001). Multivariate linear regression analysis showed that average training volume was an independent predictor of RV EDV in amateur marathoners (β = 0.642, P < 0.001). The systolic function of the RV was enhanced in amateur marathon runners in the early stage, manifested by an increase in RV EDV. After a long period of high-intensity endurance exercise, RV systolic function will temporarily be reduced. 3D-STE can identify this subclinical change with high sensitivity and provide valuable information to assess the structure and function of RV in amateur marathon runners.

Biventricular Arrhythmogenic Cardiomyopathy Associated with a Novel Heterozygous Plakophilin-2 Early Truncating Variant

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is a hereditary condition that can cause sudden cardiac death in young, frequently athletic individuals under the age of 35 due to malignant arrhythmias. Competitive and endurance exercise may hasten the onset and progression of ARVC, leading to right ventricular dysfunction and potentially fatal ventricular arrhythmias earlier in life. In this article, we present a novel, pathogenic, early truncating heterozygous variant in the PKP2 gene that causes biventricular arrhythmogenic cardiomyopathy and affects a family, of which the only member with the positive phenotype is a competitive endurance athlete.

Correlation analysis of epicardial adipose tissue and ventricular myocardial strain in Chinese amateur marathoners using cardiac magnetic resonance

Background

The volume of epicardial adipose tissue (EAT) is associated with an increased incidence of cardiovascular disease (CVD); however, only a few studies have examined its effect on the myocardial function of endurance in athletes. The association between the EAT and the variation of myocardial function is still unclear in amateur marathoners. Consequently, by using some sedentary individuals as the control, this study aims to evaluate the correlation between the EAT volume and the myocardial strain in the left and right ventricles of Chinese amateur marathoners by cardiac magnetic resonance (CMR).

Methods

A total of 30 amateur marathoners were included as the exercise group and 20 sedentary people as a control group. All participants received the cardiac magnetic resonance (CMR) to measure the left and right ventricular end-diastolic volume, end-systolic volume and volume index, stroke volume and index, cardiac output index, ejection fraction and myocardial mass, the EAT volume, global radial, circumferential, and longi-tudinal strains, and the strain rates of left and right ventricular myocardium.

Results

There was a significant difference in the EAT volume (EATV) index between the exercise group and the control group (26.82±11.76ml/m² vs 37.82±17.15ml/m², P = 0.01). Results from the multivariate linear regression analysis showed that BMI (standardized β = 0.458; P < 0.001) had an independent positive correlation with the EATV index. The EATV index was negatively correlated with the left ventricular global radial strain (GRS) (r = -0.505; P = 0.004) in the exercise group, while it is negatively correlated with right ventricular GRS (r = -0.492; P = 0.027) and positively correlated with global longitudinal strain (GLS) (r = 0.601; P = 0.005) in the control group. In the exercise group, the multivariate linear regression analysis showed that the EATV index (standardized β = -0.429; P = 0.021) was an independent determinant of the left ventricular GRS, and being a male (standardized β = 0.396; P = 0.029) was an independent determinant of the right ventricular GLS.

Conclusion

The EATV index is independently correlated with the left ventricular GRS in the amateur Chinese marathoners, also, the amateur marathon reduces the EATV index and increases the left ventricular myocardial mass, which consequently reduces the adverse effects on myocardial function.

Post-marathon Decline in Right Ventricular Radial Motion Component Among Amateur Sportsmen

Moderate physical activity has a positive impact on health, although extreme forms of sport such as marathon running may trigger exercise-induced cardiac fatigue. The explicit distinction between the right ventricular (RV) physiological response to training and maladaptive remodeling has not yet been determined. In this study, we aimed to analyze the impact of running a marathon on RV mechanics in amateur athletes using three-dimensional (3D) echocardiography (ECHO) and the ReVISION method (RV separate wall motion quantification). A group of 34 men with a mean age of 40 ± 8 years who successfully finished a marathon underwent ECHO three times, i.e., 2 weeks before the marathon (stage I), at the marathon finish line (stage II), and 2 weeks after the marathon (stage III). The ECHO findings were then correlated with the concentrations of biomarkers related to myocardial injury and overload and also obtained at the three stages. On finishing the marathon, the amateur athletes were found to have a significant (p < 0.05) increase in end-diastolic (with a median of 51.4 vs. 57.0 ml/m²) and end-systolic (with a median of 24.9 vs. 31.5 ml/m²) RV volumes indexed to body surface area, reduced RV ejection fraction (RVEF) (with a median of 51.0% vs. 46.0%), and a decrease in RV radial shortening [i.e., radial EF (REF)] (with a mean of 23.0 ± 4.5% vs. 19.3 ± 4.2%), with other RV motion components remaining unchanged. The post-competition decrease in REF was more evident in runners with larger total volume of trainings (R² = 0.4776, p = 0.0002) and higher concentrations of high-sensitivity cardiac troponin I (r = 0.43, p < 0.05) during the preparation period. The decrease in REF was more prominent in the training of marathoners more than 47 km/week. At stage II, marathoners with a more marked decrease in RVEF and REF had higher galectin-3 (Gal-3) levels (r = −0.48 and r = −0.39, respectively; p < 0.05). Running a marathon significantly altered the RV performance of amateur athletes. Transient impairment in RV systolic function resulted from decreased radial shortening, which appeared in those who trained more extensively. Observed ECHO changes correlated with the concentrations of the profibrotic marker Gal-3.

Network analysis of the left anterior descending coronary arteries in swim-trained rats by an in situ video microscopic technique

BACKGROUND

We aimed to identify sex differences in the network properties and to recognize the geometric alteration effects of long-term swim training in a rat model of exercise-induced left ventricular (LV) hypertrophy.

METHODS

Thirty-eight Wistar rats were divided into four groups: male sedentary, female sedentary, male exercised and female exercised. After training sessions, LV morphology and function were checked by echocardiography. The geometry of the left coronary artery system was analysed on pressure-perfused, microsurgically prepared resistance artery networks using in situ video microscopy. All segments over > 80 μm in diameter were studied using divided 50-μm-long cylindrical ring units of the networks. Oxidative-nitrative (O-N) stress markers, adenosine A2A and estrogen receptor (ER) were investigated by immunohistochemistry.

RESULTS

The LV mass index, ejection fraction and fractional shortening significantly increased in exercised animals. We found substantial sex differences in the coronary network in the control groups and in the swim-trained animals. Ring frequency spectra were significantly different between male and female animals in both the sedentary and trained groups. The thickness of the wall was higher in males as a result of training. There were elevations in the populations of 200- and 400-μm vessel units in males; the thinner ones developed farther and the thicker ones closer to the orifice. In females, a new population of 200- to 250-μm vessels appeared unusually close to the orifice.

CONCLUSIONS

Physical activity and LV hypertrophy were accompanied by a remodelling of coronary resistance artery network geometry that was different in both sexes.

Electrocardiographic Changes in Male and Female Amateur Marathon Runners: A Comparison Study

Physical training is gaining popularity among amateurs. Males and females exhibit different cardiac adaptation to exercise. The aim of the study was to compare the incidence of electrocardiographic abnormalities before and after the marathon between sexes. 12-lead electrocardiogram was performed in 40 male (39±8 years) and 27 female (40±7 years) amateur runners: 2-3 weeks before (Stage 1) and immediately after (Stage 2) the marathon. Abnormalities in the resting (Stage 1) and exercise (Stage 2) electrocardiograms were compared between sexes. At rest left atrial enlargement was more frequent in females than males (48 vs. 20%; p<0.05). The incidence of right atrial enlargement was significantly more common at Stage 2 than 1, both in men (43 vs. 0%; p<0.001) and in women (48 vs. 4%; p=0.001). Significant increase of P-wave amplitude was found in male runners after the marathon (0.12±0.05 vs. 0.21±0.09 mV; p<0.001 Stage 1 vs. 2), but was absent in females. QTc prolongation was observed in both sexes, however to a higher degree in males (p<0.05 for the interaction stage and sex). Although both male and female amateur marathon runners exhibit abnormalities in resting and exercise electrocardiograms, men present more exercise-induced electrocardiographic changes, which might indicate a higher propensity for post-marathon arrhythmias. Electrocardiographic screening in amateurs should be considered.

Right Ventricular Diastolic Dysfunction after Marathon Run

It has been raised that marathon running may significantly impair cardiac performance. However, the post-race diastolic function has not been extensively analyzed. We aimed to assess whether the marathon run causes impairment of the cardiac diastole, which ventricle is mostly affected and whether the septal (IVS) function is altered. The study included 34 male amateur runners, in whom echocardiography was performed two weeks before, at the finish line and two weeks after the marathon. Biventricular diastolic function was assessed not only with conventional Doppler indices but also using the heart rate-adjusted isovolumetric relaxation time (IVRTc). After the run, IVRTc elongated dramatically at the right ventricular (RV) free wall, to a lesser extent at the IVS and remained unchanged at the left ventricular lateral wall. The post-run IVRTc_IVS correlated with IVRTc_RV (r = 0.38, p < 0.05), and IVRTc_RV was longer in subjects with IVS hypertrophy (88 vs. 51 ms; p < 0.05). Participants with measurable IVRT_RV at baseline (38% of runners) had longer post-race IVRTc_IVS (102 vs. 83 ms; p < 0.05). Marathon running influenced predominantly the RV diastolic function, and subjects with measurable IVRT_RV at baseline or those with IVS hypertrophy can experience greater post-race diastolic fatigue.