Clinical Trial: Exercise-induced Changes in Cardiac Function & Morphology

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Magnetic Resonance Technique in the Assessment of Exercise-induced Long- and Short-Term Changes in Cardiac Function and Morphology

Brief Summary:

Until now it has been assumed that regular endurance training has a positive influence on cardiac function and that the positive effect increases with increasing intensity. However, little is known about the effects of intense endurance stress on the heart. According to current knowledge repeated exposure to strenuous endurance activity may lead to minor but possibly irreversible damage to the heart with resultant scarring of the heart's muscle.

Within this study we attempt to find out by different analytical methods - in particular magnetic resonance imaging (MRI) and ultrasound of the heart - to what extent the heart muscle is affected by an intense endurance exercise, i.e. the "Jungfrau-Marathon", and which changes can possibly be found. Due to repeated measurements we will obtain further information on the short-term course of possible changes.

Hypotheses: A single bout of prolonged strenuous exercise (PSE) leads to transient alteration in cardiac function accompanied by the appearance of biomarkers for myocardial damage.


Detailed Summary:

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 d
Sponsor: University Hospital Inselspital, Berne

Current Primary Outcome:

  • Quantification of edema and/or ischemic areas with MRI [ Time Frame: baseline ]
  • Quantification of edema and/or ischemic areas with MRI [ Time Frame: 24h post-marathon ]
  • Quantification of edema and/or ischemic areas with MRI [ Time Frame: 5 days post-marathon ]
  • Quantification of edema and/or ischemic areas with MRI [ Time Frame: 8 days post-marathon ]


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • anthropometric data, VO2max, resting-ECG, stress-ECG, blood analyses [ Time Frame: at baseline ]
  • Cardiac contractility by echocardiography [ Time Frame: 1h post-marathon ]
  • Cardiac contractility by echocardiography [ Time Frame: 5 days post-marathon ]
  • Cardiac contractility by echocardiography [ Time Frame: 8 days post-marathon ]
  • Cardiac contractility by echocardiography [ Time Frame: baseline ]
  • various parameters of cardiac function and morphology assessed with MRI and echocardiography [ Time Frame: baseline ]
  • various parameters of cardiac function and morphology assessed with MRI and echocardiography [ Time Frame: 1h post-marathon ]
  • various parameters of cardiac function and morphology assessed with MRI and echocardiography [ Time Frame: 1 day post-marathon ]
  • various parameters of cardiac function and morphology assessed with MRI and echocardiography [ Time Frame: 5 days post-marathon ]
  • various parameters of cardiac function and morphology assessed with MRI and echocardiography [ Time Frame: 8 days post-marathon ]
  • Post-exercise levels and dynamics of blood parameters indicating cardiac damage, cardiac overload , inflammation and hormonal stress response [ Time Frame: baseline ]
  • Post-exercise levels and dynamics of blood parameters indicating cardiac damage, cardiac overload , inflammation and hormonal stress response [ Time Frame: 1h post-marathon ]
  • Post-exercise levels and dynamics of blood parameters indicating cardiac damage, cardiac overload , inflammation and hormonal stress response [ Time Frame: 1 day post-marathon ]
  • Post-exercise levels and dynamics of blood parameters indicating cardiac damage, cardiac overload , inflammation and hormonal stress response [ Time Frame: 5 days post-marathon ]
  • Post-exercise levels and dynamics of blood parameters indicating cardiac damage, cardiac overload , inflammation and hormonal stress response [ Time Frame: 8 days post-marathon ]


Original Secondary Outcome: Same as current

Information By: University Hospital Inselspital, Berne

Dates:
Date Received: August 10, 2010
Date Started: July 2010
Date Completion:
Last Updated: February 14, 2011
Last Verified: February 2011