Nigerian Journal of Cardiology

ORIGINAL ARTICLE
Year
: 2015  |  Volume : 12  |  Issue : 2  |  Page : 111--114

Structural and functional adaptations to exercise: Echocardiographic findings among professional footballers on routine screening among Nigerians - A view of athletes' heart


Akintunde A Adeseye, Kareem O Lookman 
 Department of Medicine, Ladoke Akintola University of Technology and Lautech Teaching Hospital, Ogbomoso, Nigeria

Correspondence Address:
Akintunde A Adeseye
P. O. Box - 3238, Osogbo
Nigeria

Abstract

Introduction: Prolonged professional exercises such as it occurs among professional footballers are associated with functional and structural cardiac changes. It may also worsen already existing cardiovascular abnormalities. Reports are scarce on the pattern of echocardiographic changes among professional footballers in Nigeria. This study aimed to describe the structural and functional changes among Professional Footballers undergoing routine pre-season screening in Nigeria. Materials and Methods: Forty-nine active top-division club members of a Division 1 Football Club in Nigeria who had echocardiography were compared to 24 age- and sex-matched controls. They had 2-D, M-mode and Doppler echocardiography. Statistical analysis was done using SPSS 17.0. Results: The mean age of the footballers was 22.2 ± 6.3 years and they were well matched with the controls in age. All of them were males. Echocardiographic parameters were significantly different between professional footballers and controls. The left ventricular internal dimension in diastole, left ventricular posterior and septal wall thicknesses, right ventricular dimension, left atrial dimension and aortic root dimension were significantly higher among footballers than age-matched controls. Prevalence of left ventricular hypertrophy (67.3% vs. 16.7%, P < 0.05), RVD > 28 mm (49% vs. 4.2%, P < 0.05), LAD > 40 mm (59.2% vs. 0%, P < 0.05), AOD > 3 5 mm (12.2% vs. 0%, P < 0.05) and sclerosed mitral valve leaflets (18.4 vs. 12.5%, P > 0.05) were higher among footballers than controls. Conclusion: Professional footballing is associated with distinctive structural and functional echocardiographic adaptations among Nigerian professional footballers. A good understanding of this is important to differentiate disease states among them and also to identify high-risk individuals which may benefit from definitive intervention.



How to cite this article:
Adeseye AA, Lookman KO. Structural and functional adaptations to exercise: Echocardiographic findings among professional footballers on routine screening among Nigerians - A view of athletes' heart.Nig J Cardiol 2015;12:111-114


How to cite this URL:
Adeseye AA, Lookman KO. Structural and functional adaptations to exercise: Echocardiographic findings among professional footballers on routine screening among Nigerians - A view of athletes' heart. Nig J Cardiol [serial online] 2015 [cited 2022 Dec 2 ];12:111-114
Available from: https://www.nigjcardiol.org/text.asp?2015/12/2/111/152003


Full Text

 INTRODUCTION



The athletic heart syndrome is the constellation of clinical findings among athletes whose sports and training require a large aerobic or endurance exercise component. [1] It can also be defined as a constellation of clinical, electrocardiographic and echocardiographic variants of normal found in well-trained athletes who participate in sports requiring prolonged aerobic exercise training. [2] These findings include sinus bradycardia, atrioventricular (AV) conduction delay, systolic flow murmurs and cardiac chamber enlargement. [2],[3]

A basic understanding of the response to endurance exercise among footballers is important in evaluating subjects with heart conditions. [4] This is especially useful in predicting the risk of sudden death among profession footballers and other high demanding sporting activities. These cardiac and functional adaptations could predispose to sudden death or worsen already established cardiovascular hemodynamics and function. [5],[6] Sudden death is always a celebrated case worldwide. Akpa reported that though there is no policy for preventing sudden death among Nigerian footballers, an increased report of sudden death among them is a major concern. [7] Echocardiographic parameters among professional footballers are important to prognosticate the risk of sudden cardiac death. Echocardiography is essential to determine the structural and functional adaptations among athletes. [8],[9] There are very few data on the echocardiographic changes among professional footballers in Nigeria. This study describes the echocardiographic changes in structure, function and morphology among top level professional footballers in Nigeria.

 MATERIALS AND METHODS



This was a descriptive study. It was done at the Ladoke Akintola University of Technology Teaching Hospital, Ogbomoso, Nigeria. The participants were professional footballers of a Crown Football Club, a Division 1 Football Club in Nigeria who was recently promoted to the Elite Division 1 League of the Nigerian Football Federation Globacom Premiership League. They were undergoing their pre-season medical certification examination and had echocardiography as part of the examination done. Forty-nine members of the club had 2-Dimensional, M-mode and Doppler echocardiography performed according to the American Society of Echocardiography standardized protocols. [10] The control subjects were age-matched subjects who were not engaged in active routine professional sporting activity. Their demographic and clinical parameters including age, systolic and diastolic blood pressure, weight and height were taken. The blood pressure was taken as an average of three measurements taken when the patient has rested for at least 5 minutes using the first and the fifth korotk off sounds. The body mass index was determined using the weight (kg)/(height). [2] Parameters taken during echocardiography include left ventricular posterior wall thickness in diastole, left ventricular interventricular septal thickness in diastole (IVSd), left ventricular end diastolic dimension (LVDD), left ventricular end systolic dimension (LVSD), left atrial dimension, aortic root dimension and right ventricular dimension. The ejection fraction and fractional shortening were determined using the cubed formula. [10] Other parameters include trans-mitral Early (E) and late (A) diastolic flow. Similarly the trans-tricuspid early (E) and late A velocities were also taken.

The left ventricular mass index was determined using the Devereux formula and corrected for height 2.7 . Left ventricular hypertrophy was defined as LVMI > 51 kg/m 2.7 . [11] Statistical analysis was done using the Statistical Package for Social Science (SPSS) 17.0 Chicago, IL. Quantitative variables were summarized using means ± standard deviation while qualitative data were summarized as frequencies and percentages. Students t' test and Chi-square were used for analysis between groups. P < 0.05 was taken as statistically significant. Informed consent was taken from all participants in the study.

 RESULTS



[Table 1] shows the clinical and demographic characteristics of the study participants. The footballers were similar as regards to their mean age when compared to controls. The mean age of the footballers is 22.2 ± 6.3 years compared to that of controls, 23.4 ± 4.0 years, P > 0.05. The mean body mass index, systolic blood pressure, diastolic blood pressure and pulse pressure were also similar between the two groups. (23.79 ± 2.03 kg/m 2 , 123.5 ± 17.7 mmHg, 80.6 ± 9.9 mmHg vs. 25.3 ± 9.6 kg/m 2 , 127.9 ± 7.7 mmHg, 74.3 ± 2.6 mmHg, respectively, for footballers and controls, P > 0.05).{Table 1}

Among professional footballers in this study, the mean left atrial dimension (39.2 ± 6.3 mm vs. 31.6 ± 3.6 mm, P < 0.05), mean right ventricular dimension (27.3 ± 3.0 vs. 21.1 ± 2.0 mm, P < 0.05), and left ventricular internal dimension in diastole (49.95 ± 5.8 vs. 42.5 ± 7.5 mm) were significantly higher compared to normal controls. The mean interventricular septal thickness in diastole (11.8 ± 1.7 vs. 9.5 ± 1.6 mm, P < 0.05, respectively) and posterior wall thickness in diastole (11.4 ± 1.8 vs. 8.7 ± 1.5, P < 0.05, respectively) were also significantly higher among the footballers than normal controls. Similarly, the mean aortic root dimension measured using the M-mode echocardiogram was significantly higher among the footballers than normal controls (31.4 ± 2.9 vs. 27.7 ± 2.1mm, respectively, P < 0.01). As a measure of diastolic function, the mean transmitral early diastolic velocity (E) and mitral E/A ratio were significantly lower among footballers compared to normal controls. This is as shown in [Table 2].{Table 2}

The proportion of participants with left ventricular hypertrophy diagnosed with echocardiography was significantly higher among footballers compared to normal controls (67.3% vs. 16. 7%, P < 0.05). Among those with left ventricular hypertrophy, asymetric septal hypertrophy was noticed among 12 of them (36.4%) of those with LVH compared to 25% of normal controls. (The mean left ventricular mass index was significantly higher among footballers compared to controls (50.01 ± 14.5 vs. 40.81 ± 10.17 kg/m 2.7 respectively, P < 0.001). Those with chamber dilatation including left ventricular end diastolic dimension > 50 mm, right ventricular dimension > 28 mm and aortic root dimension > 35 mm were also significantly commoner among footballers than controls (51% vs. 25%, 49.0% vs. 4.2%, 12.2% vs. 0% respectively, P < 0.05). Those with left atrial dilatation (LAD > 40 mm) were also more likely to be footballers than normal controls (59.2% vs. 0%, P < 0.05).

The degree of mitral valve sclerosis was commoner, albeit not statistically significant among professional footballers than controls. The mitral valve abnormalities included myxomatous degeneration with mild prolapse into the left atrium, mitral regurgitation. There was no evidence of vegetations, systolic anterior motion of the anterior mitral valve leaflets or intracardiac masses among the participants.

Though ejection fraction and fractional shortening were minimally higher among footballers than controls it did not achieve statistical significance. A similar pattern was observed for the estimation of right ventricular systolic function (Tricuspid Annular Systolic pulmonary excursion) and peak pulmonary and aortic pressure gradients as shown in [Table 3].{Table 3}

 DISCUSSION



This study revealed that long-term sporting activities are associated with distinctive structural and functional echocardiographic adaptations among Nigeria professional footballers. These adaptations include chamber hypertrophy, increased left ventricular and right ventricular dimension, increased left atrial and right atrial dimension, increased left ventricular mass index, a significantly higher aortic root dimension among others. The study participants as a result of cardiac adaptation to chronic physical exertion had significantly higher left ventricular internal chamber dimension in diastole, mean higher posterior wall thickness in diastole, mean interventricular septal thickness in diastole, mean right ventricular internal dimension and mean left atrial dimension than the controls. This agrees with studies among Caucasians that have documented increased dimension among sportsmen. [12],[13],[14],[15] D'Andrea et al., showed that among professional athletes, aortic root dimension, left ventricular internal dimension in diastole and left atrial dimension were significantly larger than others who were not involved in such activity. [13],[14]

These adaptations are mediated by several mechanism: Withacute exercise, the initial increase in heart rate is associated with increased sympathetic drive and elevated nor epinephrine spillage into the circulation. There is also increased in stroke volume which is due to increased left ventricular end diastolic internal dimension. These changes are also related to hemodynamic overload which is induced by regular training.

Exercise is beneficial in many ways including lowering the all cause mortality in healthy individuals and in those with chronic diseases such as diabetes, hypertension, etc., the specific mechanism is not well understood but likely multifactorial including reduction in cardiovascular risk factors and beneficial effects on thrombosis, endothelial function, inflammation and autonomic tone. Although the risk associated with exercise is low, most are related to the cardiovascular and the musculoskeletal system. Cardiovascular causes of sudden death among young athletes include hypertrophic cardiomyopathy, coronary artery anomalies, left ventricular hypertrophy of in determinate cause, myocarditis, arryhthmogenic right ventricular cardiomyopathy, aortic valve disease, dilated cardiomyopathy and myxomatous mitral valve degeneration.

It is also worthy of note that about one-fifth of the footballers had sclerosed or myxomatous mitral valve leaflets many of which were suggestive of subclinical rheumatic valvular heart disease. The prevalence of subclinical among schoolchildren in South Africa who were asymptomatic of any cardiac disease have been noted to be in this range. [16] It is not known whether active sport can interfere with the degree of sclerosis in the mitral valve leaflets. However, the hemodynamic changes that occurred with exercise occurring in the presence of aortic valve sclerosis in those >50 years of age may progress to aortic stenosis especially in athletes with other atherosclerotic risk factors. [17],[18]

The knowledge of the basic functional and structural adaptation among professional footballers will impact echocardiographic definition of disease states in the future and this has to be taken into consideration in them when evaluating for disease states.

 CONCLUSIONS



Professional footballers in Nigeria have structural and functional adaptations as demonstrated by echocardiography. These include increased chamber dimension, ventricular chamber hypertrophy, a higher aortic root dimension and functional diastolic dysfunction. It must be emphasized that although many of the parameters still fell within normal limits, the significantly increased parameters might be further impaired in the evolution of other factors and may therefore leads to an earlier decompensation that it would have been had it been there was no antecedent derangement. Although this study is not powered to identify this, we suggest a longitudinal follow-up study of professional athletes to determine the prognostic and pathologic correlates of these adaptations. This might be essential in echocardiographic interpretations in disease states. Follow-up is also indicated to document the progression of these adaptive mechanisms and whether they actually predispose to disease states in the future.

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