Exercise-induced Changes in Cardiac Function & Morphology

Background

Despite the well documented cardio-protective effects of aerobic exercise of moderate intensity, short- and long-term consequences of strenuous exercise are less clear. There is increasing evidence that maintaining a high cardiac workload over a prolonged duration may result in transient impairment of cardiac function. Recent studies have also reported a transient increase in cardiac biomarkers after prolonged strenuous exercise. While in patients with cardiac disease the presence of cardiac dysfunction and increased cardiac biomarkers generally reflects myocardial damage, the impact of these observations in athletes is ill defined. It is a matter of concern whether in athletes such findings simply reflect a reversible response or whether repetitive events may lead to an accumulative cardiac damage. Traditional echocardiographic methods used to determine potential cardiac changes in morphology or function are investigator-dependent and may be subject to interference by cardiac pre- and afterload. Cardiac magnetic resonance imaging provides an investigator-independent and objective method to quantify cardiac dimensions and function. Delayed contrast enhancement MR imaging is a highly reproducible cardiovascular magnetic resonance imaging technique to directly visualize myocardial edema, necrosis and fibrosis.

Objective

To use cardiac and delayed contrast enhancement magnetic resonance imaging in combination with echocardiographic methods to quantify cardiac dysfunction after a single competitive PSE event and to study post-exercise changes in morphology and function as well as the post-exercise dynamics of specific markers of myocardial damage.

Methods

Cardiac and delayed contrast enhancement magnetic resonance imaging will be used in combination with echocardiographic methods to repetitively investigate post-exercise cardiac function and morphology in 10 elite athletes finishing the "Jungfrau Marathon". Biomarkers of myocardial damage are assessed simultaneously.

Post-exercise dynamics of the outcome parameters are followed over a minimum of 7 days after the exercise.

Inclusion criteria

• Participants of the Jungfraumarathon 2010
• Elite runners defined by their results in the Jungfraumarathon 2009 (not more than 4:30 h, corresponding to a delay of 90 minutes compared to the winner)

Exclusion criteria

• Contraindication for MRI
• • History of relevant cardiac disease (including cardiomyopathies)
• coronary heart disease
• coronary abnormalities
• cardiovascular risk factors
• History of any chronic disease
• drug abuse