***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The aims of this study were to establish absolute ranges for right ventricular ( RV ) structural and functional parameters for endurance athletes and to establish any impact of body size . These data may help differentiate physiologic conditioning from arrhythmogenic RV cardiomyopathy . METHODS A prospect i ve observational study design was used , and st and ard two-dimensional echocardiography was performed on 102 endurance athletes , providing RV structural indices . A two-dimensional strain ( ε ) technique was used to provide indices of RV ε and strain rate . The association of RV chamber size to body surface area ( BSA ) and functional indices was examined by simple ratio scaling as well as adoption of the general , nonlinear allometric model . RESULTS The values for RV inflow , outflow , length , and diastolic area were greater than published " normal ranges " in 57 % , 40 % , 69 % , and 59 % of the population , respectively , while 28 % of the population had RV outflow tract values greater than the proposed " major criteria " for arrhythmogenic RV cardiomyopathy . Simple ratio scaling for all RV dimensions to BSA did not produce size independence , whereas scaling for BSA allometrically did . Strain and strain rate values were consistent with published normal ranges , and there is no evidence to suggest that scaling is required . CONCLUSIONS RV chamber dimensions are larger in endurance athletes than those described by " normal ranges " and frequently meet the major criteria for the diagnosis of arrhythmogenic RV cardiomyopathy . Functional assessment of RV ε may aid in this differential diagnosis . RV size is allometrically related to BSA and therefore scaling for population -specific b exponents is encouraged Deformation analysis using 2-dimensional strain echocardiography can detect early systolic function abnormalities in patients with left ventricular hypertrophy . This study was design ed to characterize global and regional myocardial deformation using 2-dimensional strain in professional soccer players ( PSPs ) compared with control subjects and patients with hypertrophic cardiomyopathy ( HC ) . Twenty nine PSPs , 26 patients with HC , and 17 controls were investigated at rest using transthoracic echocardiography with 2-dimensional strain analysis .  Radial and transverse strains were significantly higher in PSPs compared with controls , whereas longitudinal strain was lower . Compared with patients with HC , athletes had higher values for transverse , radial , and circumferential strains . In pathologic hypertrophic segments , longitudinal strain was lower in patients with HC than in PSPs . In conclusion , 2-dimensional strain can identify specific patterns of myocardial deformation in PSPs , controls , and patients with HC . It has the potential to become a routinely used method for the differentiation of athlete 's heart and HC During incremental exercise , stroke volume ( SV ) plateaus at 40 - 50 % of maximal exercise capacity . In healthy individuals , left ventricular ( LV ) twist and untwisting ( " LV twist mechanics " ) contribute to the generation of SV at rest , but whether the plateau in SV during incremental exercise is related to a blunting in LV twist mechanics remains unknown . To test this hypothesis , nine healthy young males performed continuous and discontinuous incremental supine cycling exercise up to 90 % peak power in a r and omized order . During both exercise protocol s , end-diastolic volume ( EDV ) , end-systolic volume ( ESV ) , and SV reached a plateau at submaximal exercise intensities while heart rate increased continuously . Similar to LV volumes , two-dimensional speckle tracking-derived LV twist and untwisting velocity increased gradually from rest ( all P < 0.001 ) and then leveled off at submaximal intensities . During continuous exercise , LV twist mechanics were linearly related to ESV , SV , heart rate , and cardiac output ( all P < 0.01 ) while the relationship with EDV was exponential . In diastole , the increase in apical untwisting was significantly larger than that of basal untwisting ( P < 0.01 ) , emphasizing the importance of dynamic apical function . In conclusion , during incremental exercise , the plateau in LV twist mechanics and their close relationship with SV and cardiac output indicate a mechanical limitation in maximizing LV output during high exercise intensities . However , LV twist mechanics do not appear to be the sole factor limiting LV output , since EDV reaches its maximum before the plateau in LV twist mechanics , suggesting additional limitations in diastolic filling to the heart Left ventricular ( LV ) rotation occurs due to contraction of obliquely oriented myocardial fibres . Left ventricular twist ( LVT ) results from rotation of the apex and base in opposite directions . Although LVT is altered in various cardiac diseases , physiological factors that affect LVT remain incompletely understood . Isometric h and grip testing ( IHGT ) , a well-established laboratory-based technique to increase LV afterload , was performed for 3 min at 40 % maximum force generation in healthy human subjects ( n = 18 , mean age 29.7 ± 2.7 years ) .  Speckle-tracking echocardiography was used to measure LV volumes , LV apical and basal rotation , peak systolic LVT and peak early diastolic untwisting rate ( UTR ) at rest and at peak IHGT . IHGT led to significant increase in systemic blood pressure ( systolic , 120.6 ± 9.7 vs. 155.6 ± 14.5 mmHg , P < 0.001 ; diastolic , 67.5 ± 6.4 vs. 94.1 ± 21.1 mmHg , P < 0.001 ) and LV end-systolic volume ( 44.2 ± 7.8 vs. 50.5 ± 10.8 ml , P = 0.005 ) , as well as a significant increase in heart rate ( 62.8 ± 11.7 vs. 84.7 ± 13.8 beats min−1 ; P < 0.001 ) . IHGT produced a significant acute reduction in LV stroke volume ( 63.9 ± 12.0 vs. 49.4 ± 7.8 ml , P < 0.001 ) . In this setting , there was a significant decrease in peak systolic apical rotation ( 11.9 ± 3.0 vs. 8.6 ± 2.2 deg , P < 0.001 ) and a result ant 25 % decrease in peak systolic LVT ( 16.6 ± 2.8 vs. 12.5 ± 2.8 deg , P < 0.001 ) . The magnitude of peak early diastolic UTR did not change ( −114.5 ± 26.4 vs. −110.6 ± 39.8 deg s−1 , P = 0.71 ) . Peak systolic apical rotation and LVT decrease during IHGT in healthy humans . This impairment of LV twist mechanics may in part underlie the LV dysfunction that can occur in the clinical context of acute increase in afterload AIMS To investigate the physiological adaptation of the right ventricle ( RV ) in response to endurance training and to define reference values for regional deformation in the RV in endurance athletes . METHODS AND RESULTS Healthy controls ( n = 61 ) , athletes ( n = 58 ) , and elite athletes ( n = 63 ) were prospect ively enrolled with a training intensity of 2.2 + /- 1.6 , 12.5 + /- 2.3 and 24.2 + /- 5.7 h/week , respectively ( P < 0.001 ) . Conventional echocardiographic parameters , tissue Doppler imaging ( TDI ) , and 2D strain echo (2DSE)-derived velocity , strain , and strain rate ( SR ) were calculated in three RV segments . Left ventricular and RV dimensions were significantly increased ( P < 0.001 ) in both groups of athletes compared with controls . Right ventricular systolic velocities and displacement were not different between the groups . Right ventricular strain and SR values were reduced in the RV basal and mid-segment in athletes . Athletes with marked RV dilatation showed lower strain and SR values in the basal ( -20.9 + /- 4.7 vs. -24.5 + /- 4.9 % , P < 0.001 and -1.23 + /- 0.31 vs. -1.50 + /- 0.33 s(-1 ) , P < 0.001 ) and mid ( -29.3 + /- 5.4 vs. -32.1 + /- 5.3 % , P = 0.017 and -1.58 + /- 0.41 vs. -1.82 + /- 0.42 s(-1 ) , P = 0.009 ) segment , whereas athletes without RV dilatation showed no significant difference compared with the controls . CONCLUSION Regional deformation and deformation rates ( TDI and 2DSE ) are reduced in the basal RV segment in athletes . This phenomenon is most pronounced in athletes with RV dilatation and should be interpreted as normal when evaluating athletes suspected for RV pathology AIMS In individuals who exercise regularly and for extended periods of time , some structural alterations in the heart , called the athlete 's heart , develop in time . These alterations vary in type , can be eccentric or concentric , depending on the nature of exercise . Speckle tracking echocardiography ( STE ) is a novel , angle-independent method that accurately and reliably measures systolic and diastolic functions of the left ventricle ( LV ) with considerably lower inter-operator variability . METHODS AND RESULTS Twenty-two marathon runners , 24 wrestlers , and 20 healthy sedentary individuals were included in the study . The average age of subjects is 17.5 ± 2.2 in marathon runners , 16.8 ± 1.9 in wrestlers , and 16.4 ± 1.8 in control group . The parameters of LV longitudinal strain ( S ) , LV longitudinal strain rate systolic ( SRS ) , LV longitudinal strain rate diastolic early filling ( SRE ) , and longitudinal strain rate diastolic late filling ( SRA ) were evaluated by apical two- , three- , and four-chamber grayscale imaging using the global longitudinal strain ( GLS ) and GLS rate ( GLSR ) . Conventional echocardiographic parameters demonstrated increased LV diameters and wall thickness in the marathon runners and increased wall thickness without increased LV diameters in the wrestlers . Systolic and diastolic functions were comparable between the marathon runners and wrestlers with conventional echocardiography . Analysis with STE , however , yielded higher systolic strain and strain rates in the athletes . Normalized GLS parameters and end-diastolic volume ( EDV ) were shown to be correlated . CONCLUSION Overall , conventional echocardiography can detect some differences between young athletes with eccentric and concentric type of athlete 's heart but it is incapable of revealing differences in intrinsic myocardial functions . However , analysis using STE demonstrated increased systolic functions in athletes commensurate with increased load , with unaltered diastolic functions Aims This study evaluated ( a ) global LV adaption to endurance versus resistance training in male athletes , ( b ) LV assessment using by modern imaging technologies and ( c ) the impact of scaling for body size on LV structural data . Methods A prospect i ve cross-sectional design assessed the LV in 18 elite endurance-trained ( ET ) , 19 elite resistance-trained ( RT ) and 17 sedentary control ( CT ) participants .  St and ard 2D , tissue Doppler and speckle tracking echocardiography assessed LV structure and function . Indexing of LV structures to body surface area ( BSA ) was undertaken using ratio and allometric scaling . Results Absolute and scaled LV end-diastolic volume ( ET : 43.7±6.8 ; RT : 34.2±7.4 ; CT 32.5±8.9 mL/m1.5 ; p<0.05 ) and LV mass ( ET : 29.8±6.6 ; RT : 25.4±8.7 ; CT 25.9±6.4 g/m2.7 ; p < 0.05 ) were significantly higher in ET compared with RT and CT . LV wall thickness were not different between ET and RT . 65 % of ET and 95 % of RT had normal geometry . Stroke volume was higher in ET compared with both RT and CT ( p<0.05 ) . Whilst regional tissue velocity data were not different between groups , longitudinal and basal circumferential strain ( ε ) was reduced in RT compared with ET . Conclusions In this comprehensive evaluation of the male athlete 's heart ( AH ) , normal LV geometry was predominant in both athlete groups . In the ET , 30 % demonstrated an eccentric hypertrophy with no concentric hypertrophy in RT . Cardiac ε data in RT require further evaluation , and any interpretation of LV size should appropriately index for differences in body size BACKGROUND The aim of this study was to investigate the systolic and diastolic properties of the right cardiac chambers ( the right ventricle and right atrium ) among different subsets of athletes to unveil potential variations in right ventricular and right atrial remodeling secondary to different training modes . METHODS A cohort of Caucasian male top-level athletes ( n = 108 ; 80 endurance athletes [ EAs ] , mean age , 31.2 ± 10 
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Conclusion Echocardiographic 2D speckle tracking can identify subtle physiological differences in adaptations to cardiac strain and twist mechanics between athletes and healthy controls .
Differences in speckle tracking echocardiography-derived parameters can be identified using suitable sporting categorizations