An enlarged heart can be seen at echocardiography or sometimes on a chest X-ray. Similarities at presentation between athlete's heart and clinically relevant cardiac problems may prompt electrocardiography (ECG) and exercise cardiac stress tests.
The presence of an enlarged heart, as seen in echocardiograms or chest X-rays, can be indicative of various conditions, including athlete's heart.  When these findings are similar to those observed in other cardiac problems, further investigations like ECGs and exercise stress tests may be necessary for a more accurate diagnosis.