In this first direct crossover comparison between real patient sonography and simulator based scanning we proved that the simulator we developed simulates the real patient examination reliably and reproducibly.

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In a comparative study 11 athletes and 11 untrained students were investigated at rest, of these 6 trained and 5 untrained individuals during exercise as well. Myocardial blood flow was measured by the argon method. Myocardial oxygen consumption, myocardial substrate uptake of glucose, lactate, and free fatty acids and cardiac output were determined by the direct Fick principle. Exercise was standardized according to 65% of an individual's maximal oxygen uptake (delta VO2 max). Coronary flow reserve was determined by dipyridamole injections. All measurements were made during hemodynamic and respiratory steady-state conditions with the subject in a supine position. At rest, myocardial blood flow and myocardial oxygen consumption were significantly lower in trained subjects compared to the untrained ones. These differences were more pronounced during heavy exercise. They cannot be explained completely by hemodynamic parameters. - During exercise, myocardial substrate uptake shifted to a predominant lactate uptake of almost 90% of total substrate uptake. Total substrate uptake as well as lactate uptake correlated significantly with myocardial oxygen. - Coronary flow reserve was lower in the trained group. It is concluded that the heart muscle of a trained individual requires less energy at a given work load than in the untrained state.

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Grundlagen zur Bewertung leistungsphysiologischer AnpassungsvorgängeDie ständige Steigerung der körperlichen Belastung im Leistungssport wirft immer wieder die Frage auf, durch welche Anpassungsvorgänge die Höchstleistungen vollbracht werden und inwieweit Schädigungen möglich sind. In einem zusammenfassenden Oberblick sollen Anpassungsrnöglichkeiten des kardio-pulmonalen Systems und metabolische Veränderungen bei schwerer körperlicher Belastung besprochen werden. Die Kenntnis der physiologischen Anpassungserscheinungen, die in der Abweichung einzelner wichtiger Parameter (Herzgröße, Elektrokardiogramm usw.) zum Ausdruck kommen, ist eine wichtige Voraussetzung bei der Abgrenzung krankhafter Veränderungen.