Echocardiographic findings in former professional cyclists after long-term deconditioning of more than 30 years
1 Cardiovascular Center, Klinik Im Park, Zurich, Switzerland
2 Outpatient Clinic Othmarsingen, Zurich, Switzerland
3 HerzZentrum, Zurich, Switzerland
4 Cardiovascular Center, Clinic for Cardiology, University Hospital Zurich, Zurich, Switzerland
5 Department of Biostatistics, University of Zurich, Zurich, Switzerland
Received 29 July 2006; accepted after revision 4 March 2007; online publish-ahead-of-print 10 May 2007.
* Corresponding author: Cardiovascular Center Zurich, Klinik Im Park, Seestr. 220, 8027 Zurich, Switzerland. Tel: +41 44 209 2020; fax: +41 44 209 2029. E-mail address: ch.attenhofer{at}attglobal.net
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Abstract |
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Background: In professional cyclists, typical changes include reversible dilatation of atria and left ventricle (LV), LV hypertrophy but normal diastolic function. Data on long-term outcome are limited.
Methods: Of all 134 former Swiss professional cyclists (PC) participating 
1x in the professional bicycle race Tour de Suisse from 1955 to 1975, 62 (42%) were recruited for a prospective case control study. The PC and a control group of 62 golfers (matched for age, gender, hypertension, present physical activity) were screened [clinical examination, history, echocardiography, measurement of proBNP (normal <227 pg/mL)].
Results: The interval since the last bicycle race as PC was 38 (15–49) years. Average age at exam was equal in controls and PC (66±6 vs 66±7 years; P = 0.73). Percentage of participants undergoing >4 h of endurance training per week was identical (P = 0.72). Total kilometers (km) on the bicycle were higher in PCs with 311,000 (60,000–975,000) than in controls (2500 [0–120,000]; P < 0.0001). PC had larger atrial volume indices (P = 0.002) and tended to have higher LV muscle mass indices (P = 0.07). Multiple regression analysis identified the total number of bicycle km as an independent factor for LV muscle mass. For left atrial size, heart rate at rest, age, years since the last bicycle race and the current hours of endurance training were identified as independent predictors. Long axis function of both ventricles (systolic velocities of mitral and tricuspid annulus) was decreased in PC (P 
0.04). There were signs of diastolic dysfunction with lower annular E' and A' velocities. ProBNP levels were comparable in both groups (P = 0.21).
Conclusion: Among former PC, there seems to be incomplete cardiac remodelling with differences in systolic and diastolic function between former PCs and controls in the long time follow-up. Former high level endurance training may have a persisting impact on cardiac size and function.
Keywords: Athlete's heart; Cyclists; Systolic function; Diastolic function; Long axis function; Left ventricular muscle mass