Abstract des Autors

The most important causes of atrial fibrillation can be divided in three separate entities, i.e.: 1) enlargement of the atria or changes in the tissue structure of the atria, 2) changes in adrenergic and/or vagal tone, 3) changes in the volume and electrolyte regulation. The relevant cardiovascular and neurohumeral adaptations in endurance athletes are: Structural cardiovascular adaptations that are characterised by normal physiological adaptations. There is an enlargement of the dimensions of the heart of approximately 10% and an improvement in the compliance of the tissue. An increase in vagal tone in rest and an enlarged capacity of the (nor)adrenergic system are normal adaptations in endurance athletes. In conditions of overloading an increase of sympathetic tone in rest is observed during the first days. In the long term such overloading can lead to a decrease in sympathetic activity in rest. Acute dehydration in endurance exercise in a hot climate and chronic magnesium deficit are contributing factors, too. The recommendations for treatment in endurance athletes are grossly equivalent to the recommendations for non sporting persons. However, some specific characteristics of endurance athletes can lead to preferential strategies. In general atrial fibrillation in endurance athletes does not necessarily lead to a restriction in athletic activity, provided that certain conditions are met. Verf.-Referat