I found a Danish interview of one of the doctors of the heart related diseases on the Danish main hospital. I think Google Translate did an alright job.
"Jesper Kjærgaard is chief physician at the Heart Center at Rigshospitalet. His colleagues are some of those investigating what may have happened.
- We will investigate whether it is a cardiac arrest that has caused the unconsciousness that Christian had. It's similar in some respects, it sounds.
The cardiologist emphasizes that he knows nothing about Eriksen's current condition.
After examining whether it was a cardiac arrest or not, an ultrasound scan of the heart to see how it pumps and whether there are any errors in it, says Jesper Kjærsgaard.
If it is not a cardiac arrest, however, it may be another group of diseases. He is also being examined for this.
- The other major group of diseases that cause cardiac arrest are coronary artery diseases such as blood clots in the heart, says the doctor.
Christian Eriksen is 29 years old. It is not typical at the age when cardiac arrest is something you are at risk for. At the same time, he is in good shape as a football player.
According to Jesper Kjærsgaard, there are examples among top athletes who out of the blue can get blood clots in the heart or who have heart rhythm diseases.
- They are difficult to see, but can be triggered by hard physical exertion, he says.
If it is a blood clot in the heart, it will typically be accompanied by chest pain and other discomfort. But if it is a arrhythmia, there are no warning signs and the person becomes unconscious immediately, he says."