Increased longitudinal contractility and diastolic function at rest in well-trained amateur Marathon runners: a speckle tracking echocardiography study

Differences in radiation-induced heart dysfunction in male versus female rats

PURPOSE

Radiation therapy remains part of the standard of care for breast, lung, and esophageal cancers. While radiotherapy improves local control and survival, radiation-induced heart dysfunction is a common side effect of thoracic radiotherapy. Cardiovascular dysfunction can also result from non-therapeutic total body radiation exposures. Numerous studies have evaluated the relationship between radiation dose to the heart and cardiotoxicity, but relatively little is known about whether there are differences based on biological sex in radiation-induced heart dysfunction (RIHD).

MATERIALS AND METHODS

We evaluated whether male and female inbred Dahl SS rats display differences in RIHD following delivery of 24 Gy in a single fraction to the whole heart using a 1.5 cm beam size (collimater). We also compared the 2.0 cm vs. 1.5 cm collimator in males. Pleural and pericardial effusions and normalized heart weights were measured, and echocardiograms were performed.

RESULTS

Female SS rats displayed more severe RIHD relative to age-matched SS male rats. Normalized heart weight was significantly increased in females, but not in males. A total of 94% (15/16) of males and 55% (6/11) of females survived 5 months after completion of radiotherapy (p < .01). Among surviving rats, 100% of females and 14% of males developed moderate-to-severe pericardial effusions at 5 months. Females demonstrated increased pleural effusions, with the mean normalized pleural fluid volume for females and males being 56.6 mL/kg ± 12.1 and 10.96 mL/kg ± 6.4 in males (p = .001), respectively. Echocardiogram findings showed evidence of heart failure, which was more pronounced in females. Because age-matched female rats have smaller lungs, a higher percentage of the total lung was treated with radiation in females than males using the same beam size. After using a larger 2 cm beam in males which results in higher lung exposure, there was not a significant difference between males and females in terms of the development of moderate-to-severe pericardial effusions or pleural effusions. Treatment of males with a 2 cm beam resulted in comparable increases in LV mass and reductions in stroke volume to female rats treated with a 1.5 cm beam.

CONCLUSION

Together, these results illustrate that there are differences in radiation-induced cardiotoxicity between male and female SS rats and add to the data that lung radiation doses, in addition to other factors, may play an important role in cardiac dysfunction following heart radiation exposure. These factors may be important to factor into future mitigation studies of radiation-induced cardiotoxicity.

Left ventricular deformation in athletes playing sports with high dynamics-insights from the three-dimensional speckle-tracking echocardiographic MAGYAR-Sport Study

Background

Earlier results suggest the role of speckle-tracking echocardiography (STE)-derived left ventricular (LV) strains in screening and could help better understanding of adaptation to exercise. The present retrospective cohort study aimed to investigate three-dimensional STE-derived LV strains representing its deformation in athletes playing sports with high dynamics with different grades of static components of their training.

Methods

The study consisted of 67 athletes (mean age: 23.6±6.4 years, 39 males). This group of athletes was further divided into the following groups: Group C.I. (high dynamic/low static) (n=12), Group C.II. (high dynamic/moderate static) (n=22) and Group C.III. (high dynamic/high static) (n=33). The control group comprised 83 age- and gender-matched non-athletic healthy volunteers (mean age: 23.6±3.2 years, 50 males).

Results

Global LV longitudinal strain (LS) representing LV lengthening or shortening (-18.5%±3.0% vs. -16.3%±2.3%, P<0.05), LV circumferential strain (CS) representing LV widening or narrowing (-29.9%±5.2% vs. -28.1%±4.8%, P<0.05) and LV area strain (AS; combination of LS and CS; -43.7%±5.4% vs. -40.9%±4.8%, P<0.05) were increased in elite athletes as compared to those of non-athlete controls. All apical LV strains proved to be increased in all athletes with enhanced basal radial strain (RS, representing LV thickening and thinning) and LS and midventricular LS, AS and 3D strain (3DS, combination of RS, LS and CS).

Conclusions

Increased LV-LS, LV-CS and LV-AS represents enhanced LV deformation in longitudinal and circumferential directions in athletes playing sports with high dynamics. This enhancement is not related to the grade of the static component of training. Some regional differences in LV strains could be detected.

Mathematical modeling of antihypertensive therapy

Hypertension is a multifactorial disease arising from complex pathophysiological pathways. Individual characteristics of patients result in different responses to various classes of antihypertensive medications. Therefore, evaluating the efficacy of therapy based on in silico predictions is an important task. This study is a continuation of research on the modular agent-based model of the cardiovascular and renal systems (presented in the previously published article). In the current work, we included in the model equations simulating the response to antihypertensive therapies with different mechanisms of action. For this, we used the pharmacodynamic effects of the angiotensin II receptor blocker losartan, the calcium channel blocker amlodipine, the angiotensin-converting enzyme inhibitor enalapril, the direct renin inhibitor aliskiren, the thiazide diuretic hydrochlorothiazide, and the β-blocker bisoprolol. We fitted therapy parameters based on known clinical trials for all considered medications, and then tested the model's ability to show reasonable dynamics (expected by clinical observations) after treatment with individual drugs and their dual combinations in a group of virtual patients with hypertension. The extended model paves the way for the next step in personalized medicine that is adapting the model parameters to a real patient and predicting his response to antihypertensive therapy. The model is implemented in the BioUML software and is available at https://gitlab.sirius-web.org/virtual-patient/antihypertensive-treatment-modeling.

Mechano-growth factor E-domain modulates cardiac contractile function through 14-3-3 protein interactomes

In the heart, alternative splicing of the igf-I gene produces two isoforms: IGF-IEa and IGF-IEc, (Mechano-growth factor, MGF). The sequence divergence between their E-domain regions suggests differential isoform function. To define the biological actions of MGF's E-domain, we performed in silico analysis of the unique C-terminal sequence and identified a phosphorylation consensus site residing within a putative 14-3-3 binding motif. To test the functional significance of Ser 18 phosphorylation, phospho-mimetic (S/E¹⁸) and phospho-null (S/A¹⁸) peptides were delivered to mice at different doses for 2 weeks. Cardiovascular function was measured using echocardiography and a pressure-volume catheter. At the lowest (2.25 mg/kg/day) and highest (9 mg/kg/day) doses, the peptides produced a depression in systolic and diastolic parameters. However, at 4.5 mg/kg/day the peptides produced opposing effects on cardiac function. Fractional shortening analysis also showed a similar trend, but with no significant change in cardiac geometry. Microarray analysis discovered 21 genes (FDR p < 0.01), that were expressed accordant with the opposing effects on contractile function at 4.5 mg/kg/day, with the nuclear receptor subfamily 4 group A member 2 (Nr4a2) identified as a potential target of peptide regulation. Testing the regulation of the Nr4a family, showed the E-domain peptides modulate Nr4a gene expression following membrane depolarization with KCl in vitro. To determine the potential role of 14-3-3 proteins, we examined 14-3-3 isoform expression and distribution. 14-3-3γ localized to the myofilaments in neonatal cardiac myocytes, the cardiac myocytes and myofilament extracts from the adult heart. Thermal shift analysis of recombinant 14-3-3γ protein showed the S/A¹⁸ peptide destabilized 14-3-3γ folding. Also, the S/A¹⁸ peptide significantly inhibited 14-3-3γ's ability to interact with myosin binding protein C (MYPC3) and phospholamban (PLN) in heart lysates from dobutamine injected mice. Conversely, the S/E¹⁸ peptide showed no effect on 14-3-3γ stability, did not inhibit 14-3-3γ's interaction with PLN but did inhibit the interaction with MYPC3. Replacing the glutamic acid with a phosphate group on Ser 18 (pSer¹⁸), significantly increased 14-3-3γ protein stability. We conclude that the state of Ser 18 phosphorylation within the 14-3-3 binding motif of MGF's E-domain, modulates protein-protein interactions within the 14-3-3γ interactome, which includes proteins involved in the regulation of contractile function.

Left Ventricular, Left Atrial and Right Ventricular Strain Modifications after Maximal Exercise in Elite Ski-Mountaineering Athletes: A Feasibility Speckle Tracking Study

Eleven world elite ski-mountaineering (Ski-Mo) athletes were evaluated for pronounced echocardiographic physiological remodeling as the primary aim of our feasibility speckle tracking study. In this context, sports-related cardiac remodeling was analyzed by performing two-dimensional echocardiography, including speckle tracking analysis of the left atrium (LA), right ventricle (RV) and left ventricular (LV) global longitudinal strain (LV-GLS) at rest and post-peak performance. The feasibility echocardiographic speckle tracking analysis was performed on eleven elite Ski-Mo athletes, which were obtained in 2022 during the annual medical examination. The obtained data of the professional Ski-Mo athletes (11 athletes, age: 18-26 years) were compared for different echocardiographic parameters at rest and post-exercise. Significant differences were found for LV-GLS mean (p = 0.0036) and phasic LA conduit strain pattern at rest and post-exercise (p = 0.0033). Furthermore, negative correlation between LV mass and LV-GLS (p = 0.0195, r = -0.69) and LV mass Index and LV-GLS (p = 0.0253, r = -0.66) at rest were elucidated. This descriptive reporting provided, for the first time, a sport-specific dynamic remodeling of an entire elite national team of the Ski-Mo athlete's left heart and elucidated differences in the dynamic deformation pattern of the left heart.

Absence of cardiac damage induced by long-term intensive endurance exercise training: A cardiac magnetic resonance and exercise echocardiography analysis in masters athletes

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Endurance long-term high level of training induces significant cardiac remodelling involving all cardiac chambers, also known as ‘athletes-heart”.

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Both left and right ventricular longitudinal strain increases significantly at exercise.

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Cardiac extracellular volume is normal in master athletes and there is no evidence of cardiac fibrosis induced by long term endurance training in master athletes.

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There is no evidence of cardiac damage induced by intensive endurance training in healthy asymptomatic master athletes.

Objectives

It is under debate whether the long-term practice of intensive endurance exercise induces chronic cardiac damage such as myocardial fibrosis and ventricle contractile dysfunction. Multimodality analysis was performed to evaluate myocardial damage induced by long term intensive endurance training in master athletes.

Methods

Thirty-three asymptomatic endurance master athletes (47 ± 6 year-old, 9,6 ± 1,7 h training/week for 26 ± 6 years), were compared to 18 sedentary controls (49 ± 7 year-old). They underwent a CMR protocol including 4 chambers morphological and late gadolinium-enhancement (LGE) analysis, left (LV) and right ventricular (RV) T1 mapping and calculation of cardiac extracellular volume (ECV). A maximal exercise echocardiography with left and right ventricular longitudinal global strain (LGS) analysis was performed. Cardiac biomarkers of fibrosis (high sensitive cardiac Troponin T, N-Terminal pro brain natriuretic peptide, N-terminal propeptide of procollagen type I and N-terminal propeptide of procollagen type III) were analysed.

Results

Athletes had larger left and right atrial volume, LV and RV end diastolic volume and increased LV and RV mass compared to controls. LGE was not found in athletes. Native T1 values of LV and RV were not significantly different in athletes compared with controls. ECV was normal in both groups (21,5%± 1,6% [18.3 – 23%] in athletes, 22%± 2,2% [18.5 – 27%] in controls). LV and RV peak exercise LGS values were higher in athletes. Cardiac biomarkers levels were normal.

Conclusion

Despite significant physiological cardiac remodelling, consistent with previous descriptions of athlete's heart, there was no evidence of myocardial fibrosis or exercise left or right ventricular dysfunction or cardiac fibrosis in endurance athletes. Our results are not supporting the hypothesis of deleterious cardiac effects induced by long term and intensive endurance exercise training.

Myocardial Work Index: A Novel Method for Assessment of Myocardial Function in South Asian Recreational Athletes

Purpose

We used a novel noninvasive method based on speckle-tracking echocardiography to evaluate myocardial performance in South Asian recreational athletes who completed a half marathon.

Methods

Transthoracic echocardiography was performed on 24 recreational athletes 48 hours before they took part in a half marathon (premarathon), within 2 hours of half marathon completion (postmarathon), and 72 hours after completion. Clinical, laboratory, and echocardiographic variables were collected. Speckle-tracking echocardiography was performed in all subjects to characterize myocardial mechanics.

Results

Mean age of participants was 41.8 ± 7.4 years, and 23 (95.8%) were male. No subject had a prior history of coronary artery disease. Significant changes in pre- and postmarathon values suggested myocardial injury, including an increase in mean brain natriuretic peptide (BNP), an increase in left atrial volume, and an overall reduction in peak left ventricular global longitudinal strain. All subjects had a similar value of global work index, the average myocardial work, premarathon. Global work index did not change in 11 patients (Group 1), and global work index increased in 13 patients (Group 2) immediately postmarathon. Group 2 patients were noted to have higher heart rate, lower end-diastolic and end-systolic volumes, and higher BNP levels, suggesting myocardial stress.

Conclusions

South Asian athletes completing a half marathon exhibited two different responses to the cardiac stress of the half marathon, as outlined by the use of myocardial work indices, a novel method for assessing cardiac performance.

Acquired Immunity Is Not Essential for Radiation-Induced Heart Dysfunction but Exerts a Complex Impact on Injury

While radiation therapy (RT) can improve cancer outcomes, it can lead to radiation-induced heart dysfunction (RIHD) in patients with thoracic tumors. This study examines the role of adaptive immune cells in RIHD. In Salt-Sensitive (SS) rats, image-guided whole-heart RT increased cardiac T-cell infiltration. We analyzed the functional requirement for these cells in RIHD using a genetic model of T- and B-cell deficiency (interleukin-2 receptor gamma chain knockout (IL2RG-/-)) and observed a complex role for these cells. Surprisingly, while IL2RG deficiency conferred protection from cardiac hypertrophy, it worsened heart function via echocardiogram three months after a large single RT dose, including increased end-systolic volume (ESV) and reduced ejection fraction (EF) and fractional shortening (FS) (p < 0.05). Fractionated RT, however, did not yield similarly increased injury. Our results indicate that T cells are not uniformly required for RIHD in this model, nor do they account for our previously reported differences in cardiac RT sensitivity between SS and SS.BN3 rats. The increasing use of immunotherapies in conjunction with traditional cancer treatments demands better models to study the interactions between immunity and RT for effective therapy. We present a model that reveals complex roles for adaptive immune cells in cardiac injury that vary depending on clinically relevant factors, including RT dose/fractionation, sex, and genetic background.

Differences in Expression of Mitochondrial Complexes Due to Genetic Variants May Alter Sensitivity to Radiation-Induced Cardiac Dysfunction

Radiation therapy is received by over half of all cancer patients. However, radiation doses may be constricted due to normal tissue side effects. In thoracic cancers, including breast and lung cancers, cardiac radiation is a major concern in treatment planning. There are currently no biomarkers of radiation-induced cardiotoxicity. Complex genetic modifiers can contribute to the risk of radiation-induced cardiotoxicities, yet these modifiers are largely unknown and poorly understood. We have previously reported the SS (Dahl salt-sensitive/Mcwi) rat strain is a highly sensitized model of radiation-induced cardiotoxicity compared to the more resistant Brown Norway (BN) rat strain. When rat chromosome 3 from the resistant BN rat strain is substituted into the SS background (SS.BN3 consomic), it significantly attenuates radiation-induced cardiotoxicity, demonstrating inherited genetic variants on rat chromosome 3 modify radiation sensitivity. Genes involved with mitochondrial function were differentially expressed in the hearts of SS and SS.BN3 rats 1 week after radiation. Here we further assessed differences in mitochondria-related genes between the sensitive SS and resistant SS.BN3 rats. We found mitochondrial-related gene expression differed in untreated hearts, while no differences in mitochondrial morphology were seen 1 week after localized heart radiation. At 12 weeks after localized cardiac radiation, differences in mitochondrial complex protein expression in the left ventricles were seen between the SS and SS.BN3 rats. These studies suggest that differences in mitochondrial gene expression caused by inherited genetic variants may contribute to differences in sensitivity to cardiac radiation.

Myocardial longitudinal strain, fitness, and heart failure risk factors in young adults

AIMS

To investigate the relationship between fitness, heart failure (HF) risk factors (age, blood pressure, and obesity), and global/regional myocardial longitudinal strain in young adults undergoing stress testing.

METHODS

Individuals 25-55 years old without any significant medical history, not taking medications, and with a normal maximal stress echocardiogram were eligible. Global and regional longitudinal strain (LS) was evaluated by 2D speckle tracking echocardiography.

RESULTS

One hundred and seventy patients were included, of which 60% were males. The mean age was 43 years old, 49% had optimal blood pressure, and 30% were obese. On average, patients achieved 10.5 (3) METS, and the global LS was -19.9 (3.1) %. Reduced fitness was associated with decreased global longitudinal strain (GLS). Those in the top GLS quartile walked on average 1 minute and 21 seconds longer compared with the lowest quartile (P < .001). The effect of fitness on LS was preferential to the mid and apex, such that there was an apex-to-base gradient. Obesity was also independently associated with reduced GLS. However, the reduction in LS in obese individuals was more prominent at the base and mid-walls with relative sparing of the apex. Similar to fitness, aging was also associated with an increase in the apex-to-base gradient of LS. Furthermore, diastolic filling parameters correlated distinctively with regional LS.

CONCLUSIONS

In young adults without cardiovascular disease, low fitness and obesity are independently associated with reduced left ventricular longitudinal strain. There is a differential effect of HF risk factors on regional longitudinal function.

Echocardiographic Evaluation of Myocardial Function in Standardbreds During the First Year of Race Training

Several studies have shown the effect of training on myocardial deformation parameters in human athletes. The aim of this prospective, longitudinal study was echocardiographic evaluation of myocardial velocities and deformation in horses during the first year of training. Twelve Standardbred yearlings were examined using tissue Doppler imaging (TDI) and two-dimensional speckle tracking (2D-ST) during the first year of race training (short axis of left and right ventricle). The first examination was performed before the beginning of training (n = 12). At the last time point, horses were fully trained and had participated in their first races (n = 10). Radial myocardial velocities were evaluated using color (c-) and pulsed-wave (PW-)TDI in the left ventricular free wall, the interventricular septum (IVS) and the right ventricular free wall from a right parasternal short-axis image. Strain and strain rate were evaluated using 2D-ST in the LW and IVS using offline analysis of the 2D grayscale images. The radial, systolic myocardial velocities in the left ventricle (LVFW) increased significantly over the year in both c- and PW-TDI. In addition, the early diastolic velocity in the LW (in cTDI) and IVS (in c- and PW-TDI) and the systolic velocity in the IVS (in cTDI) increased significantly. The 2D-ST revealed significant increases of the radial systolic and early diastolic strain rate in the IVS and of the late diastolic strain rate in the LW. Training and aging/growing had both an impact on echocardiography.

Mapping genetic modifiers of radiation-induced cardiotoxicity to rat chromosome 3

Radiation therapy is used in ~50% of cancer patients to reduce the risk of recurrence and in some cases improve survival. Despite these benefits, doses can be limited by toxicity in multiple organs, including the heart. The underlying causes and biomarkers of radiation-induced cardiotoxicity are currently unknown, prompting the need for experimental models with inherent differences in sensitivity and resistance to the development of radiation-induced cardiotoxicity. We have identified the parental SS (Dahl salt-sensitive/Mcwi) rat strain to be a highly-sensitized model of radiation-induced cardiotoxicity. In comparison, substitution of rat chromosome 3 from the resistant BN (Brown Norway) rat strain onto the SS background (SS-3BN consomic) significantly attenuated radiation-induced cardiotoxicity. SS-3BN rats had less radiation-induced cardiotoxicity than SS rats, as measured by survival, pleural and pericardial effusions, echocardiogram parameters, and histological damage. Mast cells, previously shown to have predominantly protective roles in radiation-induced cardiotoxicity, were increased in the more resistant SS-3BN hearts postradiation. RNA sequencing from SS and SS-3BN hearts at 1 wk postradiation revealed 5,098 differentially expressed candidate genes across the transcriptome and 350 differentially expressed genes on rat chromosome 3, which coincided with enrichment of multiple pathways, including mitochondrial dysfunction, sirtuin signaling, and ubiquitination. Upstream regulators of enriched pathways included the oxidative stress modulating transcription factor, Nrf2, which is located on rat chromosome 3. Nrf2 target genes were also differentially expressed in the SS vs. SS-3BN consomic hearts postradiation. Collectively, these data confirm the existence of heritable modifiers in radiation-induced cardiotoxicity and provide multiple biomarkers, pathways, and candidate genes for future analyses. NEW & NOTEWORTHY This novel study reveals that heritable genetic factors have the potential to modify normal tissue sensitivity to radiation. Gene variant(s) on rat chromosome 3 can contribute to enhanced cardiotoxicity displayed in the SS rats vs. the BN and SS-3BN consomic rats. Identifying genes that lead to understanding the mechanisms of radiation-induced cardiotoxicity represents a novel method to personalize radiation treatment, as well as predict the development of radiation-induced cardiotoxicity.

Acute Responses of Novel Cardiac Biomarkers to a 24-h Ultra-Marathon

The aim of the present study was to examine the acute effect of an ultra-endurance performance on N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiac specific troponin T (cTnT), creatinine kinase-myocardial band (CK-MB), high sensitive C-reactive protein (hsCRP), ischemia modified albumin (IMA), heart-type fatty acid binding protein (H-FABP) and cardiovascular function. Cardiac biomarkers were evaluated in 14 male ultra-marathoners (age 40 ± 12 years) during a 24 h ultra-marathon at five points (i.e., Pre-race; Marathon, 12-h run, 24-h run, and 48-h post-race). All subjects underwent baseline echocardiography assessment at least 10 days prior to the ultra-marathon and 48 h post-race. The average distance covered during the race was 149.4 ± 33.0 km. Running the ultra-marathon led to a progressive increase in hsCRP and H-FABP concentrations (p < 0.001). CK-MB and cTnT levels were higher after a 24-h run compared to pre-race (p < 0.05). Diastolic function was altered post-race characterized by a reduction in peak early to late diastolic filling (p < 0.01). Running an ultra-marathon significantly stimulates specific cardiac biomarkers; however, the dynamic of secretion of biomarkers linked to myocardium ischemia were differentially regulated during the ultra-marathon race. It is suggested that both exercise duration and intensity play a crucial role in cardiovascular adaptive mechanisms and cause risk of cardiac stress in ultra-marathoners.

Characterization of the dynamic changes in left ventricular morphology and function induced by exercise training and detraining

BACKGROUND

Although exercise-induced cardiac hypertrophy has been intensively investigated, its development and regression dynamics have not been comprehensively described. In the current study, we aimed to characterize the effects of regular exercise training and detraining on left ventricular (LV) morphology and function.

METHODS

Rats were divided into exercised (n = 12) and control (n = 12) groups. Exercised rats swam 200 min/day for 12 weeks. After completion of the training protocol, rats remained sedentary for 8 weeks (detraining period). Echocardiographic follow-up was performed regularly to obtain LV long- and short-axis recordings for speckle-tracking echocardiography analysis. Global longitudinal and circumferential strain and systolic strain rate were measured. LV pressure-volume analysis was performed using additional groups of rats to obtain haemodynamic data.

RESULTS

Echocardiographic examinations showed the development of LV hypertrophy in the exercised group. These differences disappeared during the detraining period. Strain and strain rate values were all increased after the training period, whereas supernormal values rapidly reversed to the control level after training cessation. Load-independent haemodynamic indices, e.g., preload recruitable stroke work, confirmed the exercise-induced systolic improvement and complete regression after detraining.

CONCLUSIONS AND TRANSLATIONAL ASPECT

Our results provide the first comprehensive data to describe the development and regression dynamics of morphological and functional aspects of physiological hypertrophy in detail. Speckle-tracking echocardiography has been proven to be feasible to follow-up changes induced by exercise training and detraining and might provide an early possibility to differentiate between physiological and pathological conditions.

Is there a relationship between increased aortic stiffness and segmental left ventricular deformation in elite athletes? (Insights from the MAGYAR-Sport Study)

Introduction Myocardial contractility of the left ventricle (LV) is related to arterial distensibility. Sport activity is frequently associated with changes in both LV and arterial functions. This study aimed to find correlations between three-dimensional speckle-tracking echocardiography-derived segmental LV deformation parameters and echocardiographically assessed aortic stiffness index (ASI) in athletes. This study comprised 26 young elite athletes (mean age: 26.7 ± 8.4 years, nine men). Results Among segmental circumferential strains (CSs), only that of apical anterior (r = 0.40, p = 0.05), septal (r = 0.47, p = 0.01), inferior (r = 0.59, p = 0.001), lateral (r = 0.44, p < 0.05), and midventricular anteroseptal (r = 0.44, p < 0.05) segments correlated with ASI, whereas LV-CS of the midventricular anterior segment showed a correlation tendency. Only longitudinal strain of basal anteroseptal (r = -0.46, p < 0.05) and inferoseptal (r = -0.57, p < 0.01) segments showed correlations with ASI, whereas that of the basal anterior segment had only a tendency to correlate. Some segmental multidirectional strains also correlated with ASI. Conclusions Correlations could be demonstrated between increased aortic stiffness and circular function of the apical and midventricular LV fibers and longitudinal motion of the basal septum and LV anterior wall (part of LV outflow tract) in maintaining circulation in the elite athletes.

Endurance Exercise and the Heart: Friend or Foe?

Although low- to moderate-intensity exercise has well-known cardiovascular benefits, it has been increasingly suggested that prolonged strenuous endurance exercise (SEE) could have potential deleterious cardiac effects. In effect, the term 'cardiac overuse injury' (or 'over-exercise') has been recently reported to group all the possible deleterious cardiac consequences of repeated exposure to SEE or 'over-exercise'. In this article, we provide a balanced overview of the current state of knowledge regarding the 'pros' and 'cons' of SEE from a cardiological point of view.

Strain Imaging: From Physiology to Practical Applications in Daily Practice

Non-Doppler, 2-dimensional strain imaging is a new echocardiographic technique for obtaining strain and strain rate measurements, which serves as a major advancement in understanding myocardial deformation. It analyzes motion in ultrasound imaging by tracking speckles in 2 dimensions. There are a lot of data emerging with multiple applications of strain imaging in the clinical practice of echocardiography. As incorporation of strain imaging in daily practice has been challenging, we intend to systematically highlight the top 10 applications of speckle-tracking echocardiography, which every cardiologist should be aware of: chemotherapy cardiotoxicity, left ventricular assessment, cardiac amyloidosis, hypertrophic obstructive cardiomyopathy, right ventricular dysfunction, valvular heart diseases (aortic stenosis and mitral regurgitation), cardiac sarcoidosis, athlete heart, left atrial assessment, and cardiac dyssynchrony.

Myocardial adaptation to high-intensity (interval) training in previously untrained men with a longitudinal cardiovascular magnetic resonance imaging study (Running Study and Heart Trial)

BACKGROUND

To prospectively evaluate whether short-term high-intensity (interval) training (HI(I)T) induces detectable morphological cardiac changes in previously untrained men in cardiovascular magnetic resonance imaging.

METHODS AND RESULTS

Eighty-four untrained volunteers were randomly assigned to a HI(I)T group (n=42; 44.1±4.7 years) or an inactive control group (n=42; 42.3±5.6 years). HI(I)T focused on interval runs (intensity: 95%-105% of individually calculated heart rate at the anaerobic threshold). Before and after 16 weeks, all subjects underwent physiological examination, stepwise treadmill test with blood lactate analysis, and contrast-enhanced cardiovascular magnetic resonance imaging (cine, tagging, and delayed enhancement). Indexed left ventricular (LV) and right ventricular (RV) volume (LV, 77.1±8.5-83.9±8.6; RV, 80.5±8.5-86.6±8.1) and mass (LV, 58.2±6.4-63.4±8.1; RV, 14.8±1.7-16.1±2.1) significantly increased with HI(I)T. Changes in LV and RV morphological parameters with HI(I)T were highly correlated with an increase in maximal aerobic capacity (VO2max) and a decrease in blood lactate concentration at the anaerobic threshold. Mean LV and RV remodeling index of HI(I)T group did not alter with training (0.76 ±0.09 and 0.24±0.10 g/mL, respectively [P=0.97 and P=0.72]), indicating balanced cardiac adaptation. Myocardial circumferential strain decreased after HI(I)T within all 6 basal segments (anteroseptal, P=0.01 and anterolateral, P<0.001). There was no late gadolinium enhancement in any of the participants before or post HI(I)T.

CONCLUSIONS

Sixteen weeks of HI(I)T lead to measurable changes in cardiac atrial and ventricular morphology and function in previously untrained men. This correlates with improvements in parameters of endurance capacity.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01406730.

Comparison of left ventricular mechanics in runners versus bodybuilders using speckle tracking echocardiography

Background

Athlete’s heart is a common definition for a broad spectrum of adaptations induced by intense exercise. We intended to compare left ventricular (LV) mechanics in two sports disciplines with different exercise nature: marathon runners (endurance) and bodybuilders (power).

Methods

24 marathon or ultramarathon runners (R), 14 bodybuilders (B) and 15 healthy, sedentary male volunteers (N) were investigated. Beyond standard echocardiographic protocol, parasternal short-axis and apical recordings optimized for speckle tracking analysis were acquired (Esaote MyLab 25). Using dedicated software (TomTec 2D Performance Analysis), global longitudinal (GLS), circumferential (GCS) and radial strain (GRS) were calculated by averaging the corresponding 16 LV segments. Data are presented as mean ± SD.

Results

Calculated LV mass was higher in bodybuilders compared to normal controls (R vs. B vs. N: 198 ± 52 vs. 224 ± 69 vs. 186 ± 30 g, p < 0.05). We found no difference regarding conventional systolic function parameters among the groups (ejection fraction: 55 ± 9 vs. 60 ± 6 vs. 59 ± 5%; mitral lateral S’ velocity: 10.7 ± 0.6 vs. 10.6 ± 0.4 vs. 11.0 ± 0.8 cm/s). However, speckle tracking analysis showed a different pattern of myocardial deformation in our groups: while GRS was similar, GLS was decreased in runners, GCS was decreased in bodybuilders compared to the other two groups (GLS: -19.4 ± 3.4 vs. -23.3 ± 2.1 vs. -24.1 ± 3.0; GCS: -26.6 ± 3.8 vs. -22.4 ± 4.3 vs. -26.4 ± 2.7%, p < 0.05). Significant correlations were found in runners between GLS and end-diastolic volume (r = 0.46; p < 0.05), and body surface area (r = 0.49; p < 0.05). In bodybuilders, GCS was closely related to LV mass (r = 0.61; p < 0.01) and systolic blood pressure (r = 0.42; p < 0.05).

Conclusions

While conventional morphological and functional echocardiographic parameters failed to distinguish between the athlete’s heart of the two different sport disciplines, deformation parameters showed a different pattern of LV mechanics in runners versus bodybuilders.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-015-0002-y) contains supplementary material, which is available to authorized users.