International Journal of Sports Physiology and Performance, 2016
To determine 1) the relationship between shuttle wheel test (SWT) outcomes and peak oxygen uptake... more To determine 1) the relationship between shuttle wheel test (SWT) outcomes and peak oxygen uptake (VO2peak) during that test; and 2) whether SWT and VO2peak can discriminate between different skill levels of wheelchair tennis players. 15 wheelchair tennis players performed a SWT on a tennis court while VO2 was measured continuously. Outcome measures were VO2peak and achieved stage. Relations between outcomes and Dutch wheelchair tennis ranking were calculated with Spearman correlation. Independent t-tests were used to test for differences between national and international players. Moderate correlations were found between VO2peak and SWT outcome (r=.40-.47). The tennis ranking correlated weakly with VO2peak (r=-.35) and strongly with SWT outcomes (r=-.80). A significant difference was found between national and international players for achieved stage (p=0.027) and VO2peak (p=0.027). The SWT outcome only explained a small part of the variance in VO2peak between players, hence it cannot be considered as a valid test for aerobic capacity. However, SWT outcomes are related to the skill level of the player and give a good indication of the overall peak wheelchair performance.
?gA performed tn 42 pts in 3 groups; VM undergoing revascularizatJen (R~ pts with Ischemic ca.'di... more ?gA performed tn 42 pts in 3 groups; VM undergoing revascularizatJen (R~ pts with Ischemic ca.'diomyopathy on increasing medical therapy t~'-~. • and dilated eardiomyopathy (DCM). Peak rata.pressure product (RPr: :~ ~s derived from hemodynamlca recorded duflng axerclsa and METS were ,, ,aasured from expired gas analysis. VM was defined by mismatch at pesdren emlasion tomagmphy or low-dose a~n at dobutsmlne echo. Rasutts, Groups were Comparabio with respect to age and functional status before intervention. Change (ch) in RPP and METS at fo,ow-up ~n RVS group exceeded that in lhe remainder;,
31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phos... more 31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phosphate metabolism of the myocardium. Accordingly, the purpose of the present study was to determine the metabolic response of normal human myocardium to severe atropine-dobutamine (A-D) stress. To corroborate the results from the present in vivo study, a 31P-MRS experiment was performed with a moving phantom to simulate respiratory motion. The phantom experiment showed no relation (P=.371) between the intensity ratio of two separate phosphate peaks and amplitude of phantom excursions. The phosphocreatine (PCr) and ATP signal strength and the PCr/ATP ratio were determined from the left ventricular wall in 20 healthy subjects (posttest likelihood for coronary artery disease was <2.5%) with 31P-MRS at rest and during high-dose A-D stress (rate-pressure product increased threefold). Stress-induced changes were -21% for PCr (P<.001) and -9% for ATP (P<.05). The average PCr/ATP value at rest was 1.42+/-0.18 and decreased by 14% to 1.22+/-0.20 during stress (P<.001). The phantom experiment shows that the in vivo decrease of myocardial PCr/ATP due to high-dose A-D stress we observed is not a motion artifact. Consequently, this indicates that myocardial high-energy phosphate metabolism of the normal human heart is altered at high workloads.
Exercising in the heat induces thermoregulatory and other physiological strain that can lead to i... more Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimize performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimize performance is to heat acclimatize. Heat acclimatization should comprise repeated exercise-heat exposures over 1-2 weeks. In addition, athletes should initiate competition and training in an euhydrated state and minimize dehydration during exercise. Following the development of commercial cooling systems (e.g., cooling vests), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organizers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule eve...
Scandinavian Journal of Medicine & Science in Sports, 2015
The objective of this study was to estimate the incidence and prevalence of injury and illness am... more The objective of this study was to estimate the incidence and prevalence of injury and illness among elite junior tennis players. A cohort of 73 players (11-14 years) in the 2012-2013 Dutch national high-performance program was followed for 32 weeks; all participants completed the study. The OSTRC Questionnaire on Health Problems was used to record self-reported injuries and illnesses and to record training and match exposure. Main outcome measures were average prevalence of overuse injury and illness and incidence density of acute injury. On average, players practiced 9.1 h/week (SD 0.6; range 2.3-12.0) and had 2.2 h of match play (SD 0.6; range 2.3-12.0). During the course of the study, 67 players reported a total of 187 health problems. The average weekly prevalence of all health problems was 21.3% (95% CI: 19.2-22.9), of which 12.1% (95% CI: 10.9-13.3) constituted overuse injuries and 5.8% (95% CI: 4.6-6.9) illnesses. The incidence of acute injuries was 1.2/1000 h of tennis play (95% CI: 0.7-1.7). The high occurrence of overuse injuries among elite junior tennis players suggests that an early focus on preventative measures is warranted, with a particular focus on the monitoring and management of workload.
To examine the correlation between heart rate variability and left ventricular mass in cyclists w... more To examine the correlation between heart rate variability and left ventricular mass in cyclists with an athlete's heart. Left ventricular mass and diastolic function were determined at rest and myocardial high energy phosphates were quantified at rest and during atropine-dobutamine stress in 12 male cyclists and 10 control subjects, using magnetic resonance techniques. Ambulatory 24 hour ECG recordings were obtained, and time and frequency domain heart rate variability indices were computed. In the cyclists, the mean of all RR intervals between normal beats (meanNN), the SD of the RR intervals, and their coefficient of variation were significantly greater than in control subjects (p < 0.01, p < 0.01, and p < 0.05, respectively). For cyclists and control subjects, only meanNN correlated with left ventricular mass (r = 0.48, p = 0.038). The heart rate variability indices that correlated with functional or metabolic variables were: meanNN v E/A peak (the ratio of peak earl...
Recent injury data for collegiate-level swimming and diving are limited. This study describes the... more Recent injury data for collegiate-level swimming and diving are limited. This study describes the epidemiology of men's and women's swimming and diving injuries reported by the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP) during the 2009/2010 to 2013/2014 academic years. Injuries and athlete-exposure (AE) data reported within 9 men's and 13 women's swimming and diving programmes were analysed. Injury rates, injury rate ratios (IRR), and injury proportions by body site, diagnosis and mechanism were reported with 95% CIs. The ISP captured 149 and 208 injuries for men's and women's swimming and diving, respectively, leading to injury rates of 1.54/1000 and 1.71/1000 AEs. Among females, divers had a higher injury rate (2.49/1000 AEs) than swimmers (1.63/1000 AEs; IRR=1.53; 95% CI 1.07 to 2.19). Injury rates for male divers (1.94/1000 AEs) and swimmers (1.48/1000 AEs) did not differ (IRR=1.33; 95% CI 0.85 to 2.31). Most injurie...
Magma: Magnetic Resonance Materials in Physics, Biology, and Medicine, 1998
4. Conclusions Diastolic LV function and myocardial HEP metabolism are impaired only when LVH is... more 4. Conclusions Diastolic LV function and myocardial HEP metabolism are impaired only when LVH is caused by permanent pressure or volume overload, and not by a temporary increase in cardiac workload during part of the day as in elite athletes. Therefore, training-induced and pressure/volume-overload-induced LVH seem to represent different phenotypes of LVH, possibly related to genetic reprogramming which only occurs during permanent cardiac overload [17]. Moreover, there is an association between impaired LV diastolic function and altered myocardial HEP metabolism in patients with hypertension and in patients with aortic valve disease. Finally we did not find a correlation between myocardial HEP metabolism and LV mass in any of the groups studied. The latter indicates that LVH should be regarded as an epiphenomenon to cardiac overload, and not as a primary factor causing abnormal HEP metabolism.
Journal of the American College of Cardiology, 1996
?gA performed tn 42 pts in 3 groups; VM undergoing revascularizatJen (R~ pts with Ischemic ca.'di... more ?gA performed tn 42 pts in 3 groups; VM undergoing revascularizatJen (R~ pts with Ischemic ca.'diomyopathy on increasing medical therapy t~'-~. • and dilated eardiomyopathy (DCM). Peak rata.pressure product (RPr: :~ ~s derived from hemodynamlca recorded duflng axerclsa and METS were ,, ,aasured from expired gas analysis. VM was defined by mismatch at pesdren emlasion tomagmphy or low-dose a~n at dobutsmlne echo. Rasutts, Groups were Comparabio with respect to age and functional status before intervention. Change (ch) in RPP and METS at fo,ow-up ~n RVS group exceeded that in lhe remainder;,
Aim The purpose of the study was to compare the accuracy of M-mode echocardiography and two diffe... more Aim The purpose of the study was to compare the accuracy of M-mode echocardiography and two different twodimensional echocardiographic approaches in the assessment of left ventricular mass and volumes in endurancetrained and strength-trained athletes, using magnetic resonance imaging as reference standard.
Cyclists show prominent left ventricular hypertrophy with normal geometry. The finding that the h... more Cyclists show prominent left ventricular hypertrophy with normal geometry. The finding that the hypertrophic hearts of the cyclists had normal left ventricular function and a normal phosphocreatine to adenosine triphosphate ratio suggests that sport-induced left ventricular hypertrophy is a physiological adaptation rather than a pathophysiological response.
Background-The question of whether training-induced left ventricular hypertrophy in athletes is a... more Background-The question of whether training-induced left ventricular hypertrophy in athletes is a physiological rather than a pathophysiological phenomenon remains unresolved. The purpose of the present study was to detect any abnormalities in cardiac function in hypertrophic hearts of elite cyclists and to examine the response of myocardial high-energy phosphate metabolism to high workloads induced by atropine-dobutamine stress. Methods and Results-We studied 21 elite cyclists and 12 healthy control subjects. Left ventricular mass, volume, and function were determined by cine MRI. Myocardial high-energy phosphates were examined by 31 P magnetic resonance spectroscopy. There were no significant differences between cyclists and control subjects for left ventricular ejection fraction 59Ϯ5% versus 61Ϯ4%), left ventricular cardiac index (3.4Ϯ0.4 versus 3.4Ϯ0.4 L ⅐ min Ϫ1 ⅐ m Ϫ2 ), peak early filling rate (562Ϯ93 versus 535Ϯ81 mL/s), peak atrial filling rate (315Ϯ93 versus 333Ϯ65 mL/s), ratio of early and atrial filling volumes (3.0Ϯ1.0 versus 2.6Ϯ0.6), mean acceleration gradient of early filling (5.2Ϯ1.4 versus 5.8Ϯ1.9 L/s 2 ), mean deceleration gradient of early filling(Ϫ3.1Ϯ0.9 versus Ϫ3.2Ϯ0.7 L/s 2 ), mean acceleration gradient of atrial filling (3.6Ϯ1.8 versus 4.5Ϯ1.7 L/s 2 ), and atrial filling fraction (0.23Ϯ0.06 versus 0.26Ϯ0.04, respectively). Cyclists and control subjects showed similar decreases in the ratio of myocardial phosphocreatine to ATP measured with 31 P magnetic resonance spectroscopy during atropine-dobutamine stress (1.41Ϯ0.20 versus 1.41Ϯ0.18 at rest to 1.21Ϯ0.20 versus 1.16Ϯ0.13 during stress, both PϭNS). Conclusions-Left ventricular hypertrophy in cyclists is not associated with significant abnormalities of cardiac function or metabolism as assessed by MRI and spectroscopy. These observations suggest that training-induced left ventricular hypertrophy in cyclists is predominantly a physiological phenomenon. (Circulation. 1998;97:666-672.)
It has been postulated that depending on the type of exercise performed, 2 different morphologica... more It has been postulated that depending on the type of exercise performed, 2 different morphological forms of athlete&#39;s heart may be distinguished: a strength-trained heart and an endurance-trained heart. Individual studies have not tested this hypothesis satisfactorily. The hypothesis of divergent cardiac adaptations in endurance-trained and strength-trained athletes was tested by applying meta-analytical techniques with the assumption of a random study effects model incorporating all published echocardiographic data on structure and function of male athletes engaged in purely dynamic (running) or static (weight lifting, power lifting, bodybuilding, throwing, wrestling) sports and combined dynamic and static sports (cycling and rowing). The analysis encompassed 59 studies and 1451 athletes. The overall mean relative left ventricular wall thickness of control subjects (0.36 mm) was significantly smaller than that of endurance-trained athletes (0.39 mm, P=0.001), combined endurance- and strength-trained athletes (0.40 mm, P=0.001), or strength-trained athletes (0.44 mm, P&lt;0.001). There was a significant difference between the 3 groups of athletes and control subjects with respect to left ventricular internal diameter (P&lt;0. 001), posterior wall thickness (P&lt;0.001), and interventricular septum thickness (P&lt;0.001). In addition, endurance-trained athletes and strength-trained athletes differed significantly with respect to mean relative wall thickness (0.39 versus 0.44, P=0.006) and interventricular septum thickness (10.5 versus 11.8 mm, P=0.005) and showed a trend toward a difference with respect to posterior wall thickness (10.3 versus 11.0 mm, P=0.078) and left ventricular internal diameter (53.7 versus 52.1 mm, P=0.055). With respect to cardiac function, there were no significant differences between athletes and control subjects in left ventricular ejection fraction, fractional shortening, and E/A ratio. Results of this meta-analysis regarding athlete&#39;s heart confirm the hypothesis of divergent cardiac adaptations in dynamic and static sports. Overall, athlete&#39;s heart demonstrated normal systolic and diastolic cardiac functions.
31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phos... more 31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phosphate metabolism of the myocardium. Accordingly, the purpose of the present study was to determine the metabolic response of normal human myocardium to severe atropine-dobutamine (A-D) stress. To corroborate the results from the present in vivo study, a 31P-MRS experiment was performed with a moving phantom to simulate respiratory motion. The phantom experiment showed no relation (P=.371) between the intensity ratio of two separate phosphate peaks and amplitude of phantom excursions. The phosphocreatine (PCr) and ATP signal strength and the PCr/ATP ratio were determined from the left ventricular wall in 20 healthy subjects (posttest likelihood for coronary artery disease was &lt;2.5%) with 31P-MRS at rest and during high-dose A-D stress (rate-pressure product increased threefold). Stress-induced changes were -21% for PCr (P&lt;.001) and -9% for ATP (P&lt;.05). The average PCr/ATP value at rest was 1.42+/-0.18 and decreased by 14% to 1.22+/-0.20 during stress (P&lt;.001). The phantom experiment shows that the in vivo decrease of myocardial PCr/ATP due to high-dose A-D stress we observed is not a motion artifact. Consequently, this indicates that myocardial high-energy phosphate metabolism of the normal human heart is altered at high workloads.
International Journal of Sports Physiology and Performance, 2016
To determine 1) the relationship between shuttle wheel test (SWT) outcomes and peak oxygen uptake... more To determine 1) the relationship between shuttle wheel test (SWT) outcomes and peak oxygen uptake (VO2peak) during that test; and 2) whether SWT and VO2peak can discriminate between different skill levels of wheelchair tennis players. 15 wheelchair tennis players performed a SWT on a tennis court while VO2 was measured continuously. Outcome measures were VO2peak and achieved stage. Relations between outcomes and Dutch wheelchair tennis ranking were calculated with Spearman correlation. Independent t-tests were used to test for differences between national and international players. Moderate correlations were found between VO2peak and SWT outcome (r=.40-.47). The tennis ranking correlated weakly with VO2peak (r=-.35) and strongly with SWT outcomes (r=-.80). A significant difference was found between national and international players for achieved stage (p=0.027) and VO2peak (p=0.027). The SWT outcome only explained a small part of the variance in VO2peak between players, hence it cannot be considered as a valid test for aerobic capacity. However, SWT outcomes are related to the skill level of the player and give a good indication of the overall peak wheelchair performance.
?gA performed tn 42 pts in 3 groups; VM undergoing revascularizatJen (R~ pts with Ischemic ca.'di... more ?gA performed tn 42 pts in 3 groups; VM undergoing revascularizatJen (R~ pts with Ischemic ca.'diomyopathy on increasing medical therapy t~'-~. • and dilated eardiomyopathy (DCM). Peak rata.pressure product (RPr: :~ ~s derived from hemodynamlca recorded duflng axerclsa and METS were ,, ,aasured from expired gas analysis. VM was defined by mismatch at pesdren emlasion tomagmphy or low-dose a~n at dobutsmlne echo. Rasutts, Groups were Comparabio with respect to age and functional status before intervention. Change (ch) in RPP and METS at fo,ow-up ~n RVS group exceeded that in lhe remainder;,
31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phos... more 31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phosphate metabolism of the myocardium. Accordingly, the purpose of the present study was to determine the metabolic response of normal human myocardium to severe atropine-dobutamine (A-D) stress. To corroborate the results from the present in vivo study, a 31P-MRS experiment was performed with a moving phantom to simulate respiratory motion. The phantom experiment showed no relation (P=.371) between the intensity ratio of two separate phosphate peaks and amplitude of phantom excursions. The phosphocreatine (PCr) and ATP signal strength and the PCr/ATP ratio were determined from the left ventricular wall in 20 healthy subjects (posttest likelihood for coronary artery disease was &lt;2.5%) with 31P-MRS at rest and during high-dose A-D stress (rate-pressure product increased threefold). Stress-induced changes were -21% for PCr (P&lt;.001) and -9% for ATP (P&lt;.05). The average PCr/ATP value at rest was 1.42+/-0.18 and decreased by 14% to 1.22+/-0.20 during stress (P&lt;.001). The phantom experiment shows that the in vivo decrease of myocardial PCr/ATP due to high-dose A-D stress we observed is not a motion artifact. Consequently, this indicates that myocardial high-energy phosphate metabolism of the normal human heart is altered at high workloads.
Exercising in the heat induces thermoregulatory and other physiological strain that can lead to i... more Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimize performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimize performance is to heat acclimatize. Heat acclimatization should comprise repeated exercise-heat exposures over 1-2 weeks. In addition, athletes should initiate competition and training in an euhydrated state and minimize dehydration during exercise. Following the development of commercial cooling systems (e.g., cooling vests), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organizers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule eve...
Scandinavian Journal of Medicine & Science in Sports, 2015
The objective of this study was to estimate the incidence and prevalence of injury and illness am... more The objective of this study was to estimate the incidence and prevalence of injury and illness among elite junior tennis players. A cohort of 73 players (11-14 years) in the 2012-2013 Dutch national high-performance program was followed for 32 weeks; all participants completed the study. The OSTRC Questionnaire on Health Problems was used to record self-reported injuries and illnesses and to record training and match exposure. Main outcome measures were average prevalence of overuse injury and illness and incidence density of acute injury. On average, players practiced 9.1 h/week (SD 0.6; range 2.3-12.0) and had 2.2 h of match play (SD 0.6; range 2.3-12.0). During the course of the study, 67 players reported a total of 187 health problems. The average weekly prevalence of all health problems was 21.3% (95% CI: 19.2-22.9), of which 12.1% (95% CI: 10.9-13.3) constituted overuse injuries and 5.8% (95% CI: 4.6-6.9) illnesses. The incidence of acute injuries was 1.2/1000 h of tennis play (95% CI: 0.7-1.7). The high occurrence of overuse injuries among elite junior tennis players suggests that an early focus on preventative measures is warranted, with a particular focus on the monitoring and management of workload.
To examine the correlation between heart rate variability and left ventricular mass in cyclists w... more To examine the correlation between heart rate variability and left ventricular mass in cyclists with an athlete's heart. Left ventricular mass and diastolic function were determined at rest and myocardial high energy phosphates were quantified at rest and during atropine-dobutamine stress in 12 male cyclists and 10 control subjects, using magnetic resonance techniques. Ambulatory 24 hour ECG recordings were obtained, and time and frequency domain heart rate variability indices were computed. In the cyclists, the mean of all RR intervals between normal beats (meanNN), the SD of the RR intervals, and their coefficient of variation were significantly greater than in control subjects (p < 0.01, p < 0.01, and p < 0.05, respectively). For cyclists and control subjects, only meanNN correlated with left ventricular mass (r = 0.48, p = 0.038). The heart rate variability indices that correlated with functional or metabolic variables were: meanNN v E/A peak (the ratio of peak earl...
Recent injury data for collegiate-level swimming and diving are limited. This study describes the... more Recent injury data for collegiate-level swimming and diving are limited. This study describes the epidemiology of men's and women's swimming and diving injuries reported by the National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP) during the 2009/2010 to 2013/2014 academic years. Injuries and athlete-exposure (AE) data reported within 9 men's and 13 women's swimming and diving programmes were analysed. Injury rates, injury rate ratios (IRR), and injury proportions by body site, diagnosis and mechanism were reported with 95% CIs. The ISP captured 149 and 208 injuries for men's and women's swimming and diving, respectively, leading to injury rates of 1.54/1000 and 1.71/1000 AEs. Among females, divers had a higher injury rate (2.49/1000 AEs) than swimmers (1.63/1000 AEs; IRR=1.53; 95% CI 1.07 to 2.19). Injury rates for male divers (1.94/1000 AEs) and swimmers (1.48/1000 AEs) did not differ (IRR=1.33; 95% CI 0.85 to 2.31). Most injurie...
Magma: Magnetic Resonance Materials in Physics, Biology, and Medicine, 1998
4. Conclusions Diastolic LV function and myocardial HEP metabolism are impaired only when LVH is... more 4. Conclusions Diastolic LV function and myocardial HEP metabolism are impaired only when LVH is caused by permanent pressure or volume overload, and not by a temporary increase in cardiac workload during part of the day as in elite athletes. Therefore, training-induced and pressure/volume-overload-induced LVH seem to represent different phenotypes of LVH, possibly related to genetic reprogramming which only occurs during permanent cardiac overload [17]. Moreover, there is an association between impaired LV diastolic function and altered myocardial HEP metabolism in patients with hypertension and in patients with aortic valve disease. Finally we did not find a correlation between myocardial HEP metabolism and LV mass in any of the groups studied. The latter indicates that LVH should be regarded as an epiphenomenon to cardiac overload, and not as a primary factor causing abnormal HEP metabolism.
Journal of the American College of Cardiology, 1996
?gA performed tn 42 pts in 3 groups; VM undergoing revascularizatJen (R~ pts with Ischemic ca.'di... more ?gA performed tn 42 pts in 3 groups; VM undergoing revascularizatJen (R~ pts with Ischemic ca.'diomyopathy on increasing medical therapy t~'-~. • and dilated eardiomyopathy (DCM). Peak rata.pressure product (RPr: :~ ~s derived from hemodynamlca recorded duflng axerclsa and METS were ,, ,aasured from expired gas analysis. VM was defined by mismatch at pesdren emlasion tomagmphy or low-dose a~n at dobutsmlne echo. Rasutts, Groups were Comparabio with respect to age and functional status before intervention. Change (ch) in RPP and METS at fo,ow-up ~n RVS group exceeded that in lhe remainder;,
Aim The purpose of the study was to compare the accuracy of M-mode echocardiography and two diffe... more Aim The purpose of the study was to compare the accuracy of M-mode echocardiography and two different twodimensional echocardiographic approaches in the assessment of left ventricular mass and volumes in endurancetrained and strength-trained athletes, using magnetic resonance imaging as reference standard.
Cyclists show prominent left ventricular hypertrophy with normal geometry. The finding that the h... more Cyclists show prominent left ventricular hypertrophy with normal geometry. The finding that the hypertrophic hearts of the cyclists had normal left ventricular function and a normal phosphocreatine to adenosine triphosphate ratio suggests that sport-induced left ventricular hypertrophy is a physiological adaptation rather than a pathophysiological response.
Background-The question of whether training-induced left ventricular hypertrophy in athletes is a... more Background-The question of whether training-induced left ventricular hypertrophy in athletes is a physiological rather than a pathophysiological phenomenon remains unresolved. The purpose of the present study was to detect any abnormalities in cardiac function in hypertrophic hearts of elite cyclists and to examine the response of myocardial high-energy phosphate metabolism to high workloads induced by atropine-dobutamine stress. Methods and Results-We studied 21 elite cyclists and 12 healthy control subjects. Left ventricular mass, volume, and function were determined by cine MRI. Myocardial high-energy phosphates were examined by 31 P magnetic resonance spectroscopy. There were no significant differences between cyclists and control subjects for left ventricular ejection fraction 59Ϯ5% versus 61Ϯ4%), left ventricular cardiac index (3.4Ϯ0.4 versus 3.4Ϯ0.4 L ⅐ min Ϫ1 ⅐ m Ϫ2 ), peak early filling rate (562Ϯ93 versus 535Ϯ81 mL/s), peak atrial filling rate (315Ϯ93 versus 333Ϯ65 mL/s), ratio of early and atrial filling volumes (3.0Ϯ1.0 versus 2.6Ϯ0.6), mean acceleration gradient of early filling (5.2Ϯ1.4 versus 5.8Ϯ1.9 L/s 2 ), mean deceleration gradient of early filling(Ϫ3.1Ϯ0.9 versus Ϫ3.2Ϯ0.7 L/s 2 ), mean acceleration gradient of atrial filling (3.6Ϯ1.8 versus 4.5Ϯ1.7 L/s 2 ), and atrial filling fraction (0.23Ϯ0.06 versus 0.26Ϯ0.04, respectively). Cyclists and control subjects showed similar decreases in the ratio of myocardial phosphocreatine to ATP measured with 31 P magnetic resonance spectroscopy during atropine-dobutamine stress (1.41Ϯ0.20 versus 1.41Ϯ0.18 at rest to 1.21Ϯ0.20 versus 1.16Ϯ0.13 during stress, both PϭNS). Conclusions-Left ventricular hypertrophy in cyclists is not associated with significant abnormalities of cardiac function or metabolism as assessed by MRI and spectroscopy. These observations suggest that training-induced left ventricular hypertrophy in cyclists is predominantly a physiological phenomenon. (Circulation. 1998;97:666-672.)
It has been postulated that depending on the type of exercise performed, 2 different morphologica... more It has been postulated that depending on the type of exercise performed, 2 different morphological forms of athlete&#39;s heart may be distinguished: a strength-trained heart and an endurance-trained heart. Individual studies have not tested this hypothesis satisfactorily. The hypothesis of divergent cardiac adaptations in endurance-trained and strength-trained athletes was tested by applying meta-analytical techniques with the assumption of a random study effects model incorporating all published echocardiographic data on structure and function of male athletes engaged in purely dynamic (running) or static (weight lifting, power lifting, bodybuilding, throwing, wrestling) sports and combined dynamic and static sports (cycling and rowing). The analysis encompassed 59 studies and 1451 athletes. The overall mean relative left ventricular wall thickness of control subjects (0.36 mm) was significantly smaller than that of endurance-trained athletes (0.39 mm, P=0.001), combined endurance- and strength-trained athletes (0.40 mm, P=0.001), or strength-trained athletes (0.44 mm, P&lt;0.001). There was a significant difference between the 3 groups of athletes and control subjects with respect to left ventricular internal diameter (P&lt;0. 001), posterior wall thickness (P&lt;0.001), and interventricular septum thickness (P&lt;0.001). In addition, endurance-trained athletes and strength-trained athletes differed significantly with respect to mean relative wall thickness (0.39 versus 0.44, P=0.006) and interventricular septum thickness (10.5 versus 11.8 mm, P=0.005) and showed a trend toward a difference with respect to posterior wall thickness (10.3 versus 11.0 mm, P=0.078) and left ventricular internal diameter (53.7 versus 52.1 mm, P=0.055). With respect to cardiac function, there were no significant differences between athletes and control subjects in left ventricular ejection fraction, fractional shortening, and E/A ratio. Results of this meta-analysis regarding athlete&#39;s heart confirm the hypothesis of divergent cardiac adaptations in dynamic and static sports. Overall, athlete&#39;s heart demonstrated normal systolic and diastolic cardiac functions.
31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phos... more 31P-MRS during cardiac stress may provide (patho)physiological insights into the high-energy phosphate metabolism of the myocardium. Accordingly, the purpose of the present study was to determine the metabolic response of normal human myocardium to severe atropine-dobutamine (A-D) stress. To corroborate the results from the present in vivo study, a 31P-MRS experiment was performed with a moving phantom to simulate respiratory motion. The phantom experiment showed no relation (P=.371) between the intensity ratio of two separate phosphate peaks and amplitude of phantom excursions. The phosphocreatine (PCr) and ATP signal strength and the PCr/ATP ratio were determined from the left ventricular wall in 20 healthy subjects (posttest likelihood for coronary artery disease was &lt;2.5%) with 31P-MRS at rest and during high-dose A-D stress (rate-pressure product increased threefold). Stress-induced changes were -21% for PCr (P&lt;.001) and -9% for ATP (P&lt;.05). The average PCr/ATP value at rest was 1.42+/-0.18 and decreased by 14% to 1.22+/-0.20 during stress (P&lt;.001). The phantom experiment shows that the in vivo decrease of myocardial PCr/ATP due to high-dose A-D stress we observed is not a motion artifact. Consequently, this indicates that myocardial high-energy phosphate metabolism of the normal human heart is altered at high workloads.
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