Acta Cardiologica ISSN: 0001-5385 (Print) 0373-7934 (Online) Journal homepage: http://www.tandfonline.com/loi/tacd20 The occurrence of atrial fi brillation in former toplevel handball players above the age of 50 Frank Van Buuren, Klaus P. Mellwig, Lothar Faber, Christian Prinz, Andreas Fruend, Johannes B. Dahm, Tanja Kottmann, Nikola Bogunovic, Dieter Horstkotte, Thomas Butz & Christoph Langer To cite this article: Frank Van Buuren, Klaus P. Mellwig, Lothar Faber, Christian Prinz, Andreas Fruend, Johannes B. Dahm, Tanja Kottmann, Nikola Bogunovic, Dieter Horstkotte, Thomas Butz & Christoph Langer (2012) The occurrence of atrial fi brillation in former top-level handball players above the age of 50, Acta Cardiologica, 67:2, 213-220, DOI: 10.1080/AC.67.2.2154212 To link to this article: https://doi.org/10.1080/AC.67.2.2154212 Published online: 23 May 2017. Submit your article to this journal Article views: 2 View related articles Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=tacd20 Acta Cardiol 2012; 67(2): 213-220 213 doi: 10.2143/AC.67.2.2154212 The occurrence of atrial fibrillation in former top-level handball players above the age of 50 Frank VAN BUUREN1, MD; Klaus P. MELLWIG1, MD; Lothar FABER1, MD, PhD; Christian PRINZ1, MD; Andreas FRUEND1; Johannes B. DAHM2, MD; Tanja KOTTMANN1, MD; Nikola BOGUNOVIC1, Dieter HORSTKOTTE1, MD, PhD; Thomas BUTZ1,3, MD; Christoph LANGER1,4, MD 1 Dept. of Cardiology, Heart and Diabetes Center North Rhine-Westphalia, Ruhr University Bochum, Germany; 2Dept. of Cardiology and Angiology, New Bethlehem Hospital, Goettingen, Germany; 3Dept. of Cardiology and Angiology, Marienhospital Herne, Ruhr University Bochum, Germany; 4Dept. of Cardiology and Angiology, University Schleswig Holstein, Campus Kiel, Germany. Objective Cardiac adaptation to sports activity in endurance athletes is considerably different from that in power athletes. The effects of a highlevel team sport like handball, one of the most popular sports in the world, performed at a younger age, on cardiac rhythm in individuals above the age of 50 have not been investigated to date. Methods Thirty-three former top-level handball players from the first German league (6 former world champions and numerous Olympians) (57.5 ± 5.5 y) joined our screening programme for former athletes and underwent electrocardiography, echocardiography and spiroergometry. Data were compared to 24 sedentary healthy controls. Results Ten of the 33 athletes suffered from atrial fibrillation (AF). Left ventricular diameter was 53.68 ± 4.88 mm in the athletes group and 50.58 ± 4.12 mm in the healthy controls. Analysing the subgroups of handball players (‘AF group’ and ‘non-AF group’), spiroergometry showed oxygen consumption at the anaerobic threshold of 27.54 ± 6.77 ml/kg/min in the AF group and 31.24 ± 10.33 ml/kg/min in the non-AF group (P = 0.228). Absolute left atrial diameter was 44.34 ± 4.41 mm in the AF group (non-AF group 38.94 ± 3.77 mm, P < 0.001) (healthy controls 37.54 ± 4.34 mm, compared with all athletes P = 0.015). In all individuals left ventricular wall thickness was within normal limits. However, myocardial walls were thicker in the AF group (11.28 ± 1.83 mm) than in the non-AF group (9.44 ± 1.26 mm, P = 0.002). Athletes in the AF group (187.6 ± 6.42 cm) were significantly taller than in the non-AF group (180.91 ± 7.31 cm, P = 0.018). Conclusion Not only endurance training, but also sports activity with a relevant static component, like team handball, might predispose for AF above the age of 50. LA size, height and myocardial wall thickness seem to affect the risk of developing AF. More data in non-endurance sports are mandatory to confirm this hypothesis. Keywords Endurance training – vagal tone – atrial fibrillation – static component – team sport – handball – athlete’s heart. INTRODUCTION It is well documented that regular physical activity contributes to physical fitness beyond the age of 50 years due to an optimized arteriovenous oxygen difference Address for correspondence: Frank van Buuren, M.D., Heart and Diabetes Center North Rhine-Westphalia, Dept. of Cardiology, Ruhr University Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany. E-mail: fvbuuren@hdz-nrw.de Received 7 September 2011; revision accepted for publication 4 January 2012. and increases in left ventricular volume, stroke volume and diastolic filling1. The age-associated decline in maximal aerobic capacity is attenuated in healthy athletes who continue to engage in habitual exercise compared with sedentary individuals2. A coexisting atrial fibrillation (AF) impairs this positive effect of sport as it might be associated with severe and disturbing symptoms reducing quality of life, as well as increasing mortality3. Moreover, diabetes, hypertension and ischaemic heart disease are less frequent among physically active individuals4. However, there is no data showing that AF may impact on mortality in athletes. AF is assumed to be the most common tachyarrhythmia in active athletes5. Nevertheless, the prevalence of 214 F. van Buuren et al. this disease in people younger than 25 years in the general population is very low6. Several years of intense training in the active phase, particularly in endurance sport, has been identified as a risk factor for the development of AF in elderly athletes7-9. Some studies have shown that endurance athletes are at an approximately five times higher risk of developing AF than those who are sedentary3,10 and intense training might predispose to develop bradyarrhythmia11. The pathophysiology of AF in athletes is poorly understood and has moved into the focus of clinical trials12-14. Different mechanisms have been discussed as reasons for developing AF: (a) a slight dilatation of cardiac cavities due to regular physical activity, (b) an increased vagal tone with an associated tendency towards bradycardia13,15, and (c) fibrogenesis16. Coumel17 described how, in some patients, atrial fibrillation predominantly appeared in a vagal context (e.g. at night, a few hours after intense exercise or after heavy meals, etc.). Other reports mainly discuss the relationship between long-term endurance training and atrial fibrillation18-20. Only scant data are available about former top level athletes who have not been exclusively involved in sports with a dynamic component, but also with a moderate to high degree of static elements, like handball21. The aim of this descriptive study is to provide new information about the possible influence of professional moderate and intense static physical activity in combination with dynamic components (handball) at a young age on the incidence of AF at the age of over 50 years. METHODS In our national screening programme for former athletes we included 33 consecutive former top-level handball players older than 50 years who joined the programme on a voluntary basis. All played handball in the first German league (‘Bundesliga’), including 12 former national players and 6 world champions. Fifteen athletes had achieved international recognition in the Olympics. None of them was still active in sports at a higher level (> 3 hours per week). Although the total lifetime hours of sport could not be determined precisely, all athletes described a period of more than 20 years, with at least 18 hours of sport per week. The percentage of exclusive endurance training was about 20% of this time. However, the proportion of dynamic components during team sport like handball is also noteworthy. The time after stopping competitive sports was hard to find out as there were several athletes who did not quit their sport on a professional level abruptly. However, 31 of the 33 athletes had terminated more than 20 years before entering the study. According to their history of AF, the athletes were assigned to an AF group (n = 10) or a non–AF group (n = 23) for subgroup analysis. Data were evaluated against 24 sedentary healthy age-matched controls who had not been engaged in sports at a higher level at any time. They had comparable clinical and anthropometric characteristics and joined our screening programme on a voluntary basis. Apart from the episodes of AF, all 57 individuals (athletes and controls) were presumed to be healthy. None suffered from arterial hypertension. Besides the anamnesis and a physical examination, all individuals underwent a 12-lead ECG. Height and weight were measured in underwear and bare feet. Body mass index (BMI) and body surface area (BSA) were calculated from these data. Alcohol consumption was queried as a standardized question, quantified by the average daily consumption of alcohol in grams during the past year. More than 10 grams was the threshold for increased alcohol consumption. All individuals were below this line. Systolic and diastolic blood pressures were measured at rest in a stress-free setting following standardized methods and, in addition, directly before and during the physical stress test. The use of drugs at the time of ECG recording was queried. None of the individuals had taken cardiac drugs when AF appeared for the first time. Four of the athletes with AF had the first ECG documentation in another hospital or with their general practitioner. These patients were evaluated in our clinic within 1 week of first AF manifestation. Conventional echocardiography was performed according to the ASE guidelines (GE Vingmed Seven)22. Left-ventricular end diastolic index (LVEDDi) and leftatrial end systolic diameter index (LAESDi) were calculated by using body surface area (BSA). Measurement of cavity size and wall thickness was derived from M-mode recording. Diastolic dysfunction was defined as an E/A ratio less than 1. Six athletes displayed sinus rhythm at the time of investigation. The stress test was performed by spiroergometry (ZAN 600 USB CPX, h/p/cosmos quasar, Oberthulba, Germany). At the beginning and in the middle of each level of the physical stress test, blood pressure and heart rate were measured. Workload was increased every 2 minutes by 25 Watts, starting at 50 Watts. Workload was stopped on reaching the anaerobic threshold (AT VO2) or full exhaustion (peak VO2). The study was approved by the local ethics committee. It meets international ethical standards and respects the Declaration of Helsinki23. The statistical analyses were performed using SPSS for Windows, version 18.0 (SPSS Inc., U.S.A.). The continuous variables were presented as means and medians, while standard deviations and quartiles were chosen as Atrial fibrillation in handball players measures of dispersion. Regarding their normal distribution, the continuous variables were tested by means of the Shapiro-Wilk-test. For the comparison of two independent, normally distributed samples, the t-test was applied after the homogeneity of the variances had been tested by means of the Levene test. Due to the proven homogeneity of the variances, the Student t-test was carried out. However, for non-normally distributed samples the MannWhitney U test was applied as a non-parametric procedure. A P-value of < 0.05 was assumed as statistically significant for all statistical tests. For the diagrams, which were also compiled with SPSS, box plots were chosen to visualize the medians and quartile distances. While the median, as well as the 25th-75th percentile, are displayed in the boxes, the t-bars represent the smallest and largest values. Outliers are considered values located between 1½ and 3 box lengths outside the box; they are represented as circles in the diagram. RESULTS We studied 57 male individuals (33 former athletes and 24 healthy controls). Mean age in the athlete group was 57.55 ± 5.52 years (y) (healthy controls 56.54 ± 5.78 y, P = 0.559). Mean body weight (bw) was 87.33 ± 9.98 kg (82.92 ± 10.28 kg, P = 0.109), mean height was 182.94 ± 7.62 cm (178.96 ± 6.29 cm, P = 0.041). In all individuals hyperthyroidism was excluded by TSH laboratory test. None of the participating individuals had an average alcohol consumption of more than 10 g/day during the last year. Mean age of the athletes in the non-AF group (n = 23) was 57.39 ± 5.26 y (AF group (n = 10) 57.90 ± 6.37 y, P = 0.859). Mean weight was 84.61 ± 8.91 kg (AF group 93.60 ± 9.88 kg, P = 0.015), mean height 180.91 ± 7.31 cm (AF group 187.60 ± 6.42 cm, P = 0.018). Echocardiography showed that in all individuals (athletes and healthy controls) systolic function was normal and no structural heart disease was present. Ten (30.3%) of the former athletes suffered from AF (AF group). Six of them displayed sinus rhythm at the time of examination in our programme, four showed AF. Seven suffered from paroxysmal AF, three from persistent AF. Six of the patients in the AF group (others refused drug therapy) and none of the non-AF group or the healthy control group were taking beta blockers. The mean age of AF patients at the time of diagnosis was 53.6 ± 3.13 y. Out of the 10 athletes with AF four had no symptoms at the time of detecting AF, five had mild symptoms (EHRA classification II, normal daily activity not affected), one had severe symptoms (EHRA III) like palpitations and shortness of breath24. In the AF subgroup there was a longer PQ interval (199.17 ± 58.17 sec) in comparison to the non-AF group (180.36 ± 24.41 sec) (P = 0.414). Other ECG and spiroergometry findings, including blood pressure, are summarized in table 1. Absolute diameters of LVEDD in the AF subgroup was 55.33 ± 4.58 mm and in the non-AF subgroup 52.96 ± 4.93 mm (corresponding LA ESD 44.34 ± 4.41 mm and 38.94 ± 3.77 mm). LVEDDi was 25.16 ± 2.59 mm/m2 in the AF group and 25.77 ± 2.47 mm/m2in the non-AF group (P = 0.524). LAESDi was 20.15 ± 2.17 mm/m2 in the AF group (non-AF group 18.97 ± 2.07 mm/m2) (P = 0.149). In both subgroups diameters of IVS and PW were within normal limits. Posterior wall (PW) thickness was significantly higher in the AF group (11.28 ± 1.83 mm) in comparison to the non-AF group (9.44 ± 1.26 mm) (figure 1). In relation to body surface area, the group of athletes showed a mean LVEDDi of 25.59 ± 2.48 mm/m2, healthy controls were at 24.86 ± 2.22 mm/m2 (P = 0.258). LAESDi was 19.33 ± 2.14 mm/m2 (athletes) and 18.63 ± 2.02 mm/m2 (healthy controls, P = 0.219). In both groups wall thickness of the intraventricular septum (IVS) and the PW was within normal limits (table 2). Parameters of left ventricular diastolic function were normal, indicated by an E/A ratio of > 1 in all 53 individuals. Four athletes were excluded from analysis because they had AF at the time of investigation. Other echocardiographic parameters are summarized in table 2. DISCUSSION AF is a frequently occurring arrhythmia that demands further treatment. In population studies the average prevalence of AF is 0.5% in individuals aged 45-54 years, about 1% at the age of 55-64 and 4% at the age of 65-74 years8. Several recent studies have confirmed the relationship between endurance training and AF3,8,10,12,14,18-20. Data on team sports like handball are rare. In the presented study we found a rather high proportion of former top athletes with AF suggesting that atrial arrhythmia could be more common in these individuals. However, this result should not be overinterpreted as there is also a relevant endurance training aspect in handball and the investigated group of athletes is rather small. Atrial enlargement and left ventricular hypertrophy, both features of the endurance athlete’s heart, may increase the risk of suffering from AF12,14,18. Also, vegetative settings are a suggested reason for AF. Physical activity and increased sympathetic stimuli may act as triggers for AF in individuals with concomitant predisposing 215 216 F. van Buuren et al. Table 1 ECG findings, blood pressure and physical performance of athletes and healthy controls, as well as analysis of subgroups (non-AF group and AF group) Athletes (n = 33) Healthy controls (n = 24) Non-AF group (n = 23) AF group (n = 10) mean ± SD (median) mean ± SD (median) mean ± SD (median) mean ± SD (median) 57.55 ± 5.52 (58.0) 56.54 ± 5.78 (56.50) 0.559 57.39 ± 5.26 (58.00) 57.90 ± 6.37 (57.50) 0.859 Height (cm) 182.94 ± 7.62 (183.0) 178.96 ± 6.29 (179.0) 0.041 180.91 ± 7.31 (182.0) 187.60 ± 6.42 (186.0) 0.018 Weight (kg) 87.33 ± 9.98 (89.00) 82.92 ± 10.28 (80.00) 0.109 84.64 ± 8.91 (86.00) 93.60 ± 9.88 (94.00) 0.015 BMI (kg/m2) 26.06 ± 2.21 (25.7) 25.87 ± 2.63 (25.8) 0.766 25.84 ± 2.27 (25.21) 26.57 ± 2.08 (26.16) 0.338 Heart rate at rest (beats/min) a 59.47 ± 9.62 (63.0) 60.04 ± 5.56 (61.0) 0.806 60.91 ± 8.33 (64.0) PQ interval (ms) b 184.39 ± 33.94 (180.0) 174.04 ± 27.05 (180.0) 0.350 88.78 ± 15.21 (90.0) 77.83 ± 16.15 (70.0) Systolic blood pressure at rest (mmHg) a 126.39 ± 13.83 (126.0) 122.21 ± 10.83 (125.0) 0.223 128.09 ± 15.65 (131.0) 122.50 ± 7.55 (122.5) 0.293 Diastolic blood pressure at rest (mmHg) a 80.06 ± 8.13 (80.0) 78.33 ± 7.03 (81.0) 0.406 81.61 ± 8.63 (82.0) 76.50 ± 5.47 (76.0) 0.098 Maximum systolic blood pressure (mmHg) a 205.15 ± 28.22 (207.0) 197.17 ± 20.72 (201.0) 0.245 207.13 ± 28.85 (210.0) 200.60 ± 27.63 (196.0) 0.550 Maximum diastolic blood pressure (mmHg) a 90.76 ± 13.92 (92.0) 93.17 ± 13.95 (91.5) 0.522 93.48 ± 15.03 (97.0) 84.50 ± 8.63 (82.0) 0.089 AT VO2 (ml/kg bw) a 30.05 ± 9.38 (29.8) 25.72 ± 9.33 (25.1) 0.095 31.24 ± 10.33 (35.6) 27.54 ± 6.77 (29.2) 0.228 Peak VO2 (ml/kg bw) a 36.97 ± 8.14 (37.0) 31.02 ± 8.83 (29.5) 37.91 ± 9.09 (37.5) 35.01 ± 5.58 (34.7) 0.363 Age (y) QRS duration (ms) b p value 0.017 0.012 p value 56.3 ± 11.84 (56.0) 0.152 180.36 ± 24.41 (180.0) 199.17 ± 58.17 (197.5) 0.414 90.77 ± 15.11 (92.5) 84.4 ± 15.25 (90.0) 0.232 a = t-test; b = Mann-Whitney U test, bw = body weight. AT VO2: oxygen uptake at anaerobic threshold, peak VO2: maximum oxygen uptake. Table 2 Echocardiographic characteristics of athletes and healthy controls (absolute parameters and indexed by body surface area) as well as analysis of subgroups (non-AF group and AF group) a Athletes (n = 33) Healthy controls (n = 24) Non-AF group (n = 23) AF group (n = 10) mean ± SD (median) mean ± SD (median) mean ± SD (median) mean ± SD (median) LVEDD (mm) a 53.68 ± 4.88 (54.0) 50.58 ± 4.12 (51.5) 0.015 52.96 ± 4.93 (53.0) 55.33 ± 4.58 (55.0) 0.205 LVEDDi (mm/m2) a 25.59 ± 2.48 (25.7) 24.86 ± 2.22 (24.6) 0.258 25.77 ± 2.47 (26.1) 25.16 ± 2.59 (25.1) 0.524 LAESD (mm) a 40.58 ± 4.65 (41.0) 37.54 ± 4.34 (39.5) 0.015 38.94 ± 3.77 (39.0) 44.34 ± 4.41 (43.5) 0.001 LAESDi (mm/m2) a 19.33 ± 2.14 (19.2) 18.63 ± 2.02 (19.3) 0.219 18.97 ± 2.07 (19.0) 20.15 ± 2.17 (19.7) 0.149 LV IVS ED (mm) b 10.41 ± 1.54 (10.5) 10.38 ± 1.10 (11.0) 0.915 10.08 ± 1.56 (10.3) 11.16 ± 1.27 (11.1) 0.063 LV PW ED (mm) b 10.00 ± 1.66 (10.0) 10.63 ± 0.97 (10.5) 0.071 9.44 ± 1.26 (9.4) 11.28 ± 1.83 (11.2) 0.002 p value p value = t-test; b = Mann-Whitney U test. LVEDD: left ventricular end diastolic diameter, LVEDDi: left ventricular end diastolic diameter index, LAESD: left atrial end systolic diameter, LAESDi: left atrial end systolic diameter index, LV IVS ED: left ventricle interventricular septum end diastolic, LV PW ED: left ventricular posterior wall end diastolic. Atrial fibrillation in handball players a b c d Fig. 1 Findings in athletes (AF group and non-AF group) for (a): absolute dimensions of LA (left atrium) and LV (left ventricle) and (b): wall thickness of interventricular septum and posterior wall. LV EDD = left ventricular end diastolic diameter; LAESD = left atrium end systolic diameter; LV IVS ED = left ventricle interventricular septum end diastolic diameter; LV PW ED = left ventricle posterior wall end diastolic diameter. Fig. 2 Peak Vo2 and age. conditions like hypertension25. On the other hand, due to an increased parasympathetic activity that accompanies physical conditioning, athletes might have a higher prevalence for AF, especially at rest26. Most of the arrhythmias in athletes seem to be of vagal origin (57%) since they occur more commonly during sleep or after heavy meals, in comparison to 18% in a group of sedentary controls13. The role of anabolic steroids in the development of AF is largely unknown and still requires further trials25. The main aspect of our study is the relationship between AF and types of sport, according to the Classification of Sports21, with more static components. In contrast to endurance training, team handball is a sport with at least a moderate static component. We evaluated the very special population of 33 former top German handball players who showed a high prevalence of AF (30.3%). Although all athletes were screened in our national programme for top-level handball players, a selection bias could not be ruled out as we did not see all former athletes and the individuals suffering from AF, due to complaints, might be more motivated to have their heart rhythm checked. Heart rhythm of all individuals has been evaluated on several occasions by 12-lead ECG. We did not apply Holter ECG in the individuals supposed to be free from arrhythmia and so we cannot comment on potential patients with paroxysmal AF and no symptoms. The concrete reason for AF in the presented trial remains debatable because sport-adaptive 217 218 F. van Buuren et al. cardiac changes could not be ruled out as we did not apply myocardial biopsy. Our athletes were evaluated after many years of sport practice, when some of them had already reduced their physical training to a rather low level. All individuals were free from the mentioned co-factors like hyperthyroidism, arterial hypertension and high alcohol consumption. In athletes, an increased vagal tone might also harbour the risk of developing a first- and second-degree AV block. Braumann27 states that up to 33% of endurance-trained individuals have a first-degree AV block. This was supported by our AF group, which showed a longer PQ time (in comparison to the non-AF group and the healthy controls). However, this was still within normal range and not significant (table 1) and for this reason it could to be of limited relevance. Interestingly, 3 (one of them taking beta blockers) out of 10 individuals in the AF group showed a first-degree AV block, whereas only 2 out of 23 (9%) did so in the non-AF group. Athletes also had a longer QRS duration, when compared with healthy controls, which is in line with recently published findings in college students28. Analysing the subgroups, individuals in the AF group were significantly taller than in the non-AF group (P = 0.018), which complies with previous studies by Mont, who found a relationship between height and the incidence of AF in middle-aged individuals14. In our study we also found a significant correlation between weight and AF in the athletes’ subgroups, suggesting that body dimension influences the tendency to develop AF. However, these findings could not be confirmed for BMI. The data derived from the exercise test did not show a significant difference between the groups concerning blood pressure or the level of fitness at the anaerobic threshold (AT VO2). Hence, AF provoked by concealed arterial hypertension was unlikely. Healthy controls showed a lower fitness level. Only peak VO2 differed significantly (P = 0.012), whereas AT VO2 was not significantly different (table 1, figure 2). Both LA and LV cavity remodelling observed in trained athletes represent the physiological consequence of the global cardiac adaption to increased preload associated with intensive training, a fact mainly seen in athletes engaged in endurance training26,29-32. Thus, echocardiography is essential to rule out other underlying diseases (e.g. hypertrophic cardiomyopathy) that might be responsible for AF. Especially left atrial remodelling is an additional physiological adaptation in well-trained individuals which can be explained by associated LV cavity enlargement and volume overload. Pelliccia published data in 2005 stating that left atrial enlargement defined by a transverse anteroposterior diameter from the M-mode of more than 40 mm can be found in about 20% of active competitive athletes30. In contrast to other authors, it was postulated that the enlargement is benign and only rarely associated with AF3,30 as there were only 0.8% of athletes with enlarged LA diameters who suffered from paroxysmal AF in the investigated population. Analysing the athletes’ subgroups in our study, both LVEDD (P = 0.205) and LAESD (highly significant, P = 0.001) were higher in the AF group. However, when matched with the body surface area, LVEDDi and LAESDi turned to normal, suggesting a coherency between absolute dimensions of left atrium and AF. This has to be interpreted in the light of previous studies. Bjørnstad19 published a study of 30 former top-level endurance-trained athletes who had not detrained yet and confirmed studies that maintained physical activity leads to an ongoing enlargement of LA and LV. Other authors showed a reduction in previously enlarged heart cavities when training is reduced significantly33. The hypothesis that the development of an athlete’s heart is a benign and reversible process after detraining clashes with the findings in our study because there seems to be a relationship between AF and intensive physical activity that is not only focused on endurance training. Cardiac dimensions of athletes and healthy controls did not differ when indexed for BSA, raising the assumption that it is not the size of cardiac chambers in relationship to body dimensions that makes the difference, but more the structural changes of the myocardium and the absolute dimensions. Healthy controls showed higher values for left-ventricular PW diameters in comparison to athletes. Although this finding suggests relatively normal parameters for the individuals engaged in sport during their youth, the subgroup analysis taught a different lesson. The AF group showed a significantly thicker posterior wall in comparison to the other former athletes, strengthening the assumption that an increased hypertrophic response due to physical activity at a high level might be associated with a higher tendency to develop AF. However, enlarged wall thickness was not seen in the IVS, leaving this point to discussion. Although these data were collected in a series of consecutive individuals in our national screening programme for former top-level handball players, we cannot rule out a selection bias. It has to be taken into account that the cohort investigated is small because of its very special focus on top-level handball players. Further case control and longitudinal studies might further clarify the relationship between AF and high-level non-endurance sports at a young age. Atrial fibrillation in handball players CONCLUSION It is generally well accepted that regular physical activity might predispose to develop AF at an older age. The presented study could show that this finding might not only be associated with endurance training, but also with physical activity in the field of handball - a sport classified as moderately static and highly dynamic. Hence, our findings are in line with the literature but need further confirmation through screening more former athletes. Sports activity at a young age maintains maximum oxygen consumption at a significantly higher level above age 50 compared with healthy controls, even though intense regular physical activity has been terminated. However, based on this study, we have to consider limits concerning an ‘adequate use’ of sports, despite the positive effects of regular training on coronary heart disease and premature cardiac death. Furthermore, in contrast to some other authors, the data underline the relevance of height and LA size in athletes with AF. These findings need further trials to confirm the relevance of ‘non-endurance training’. 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