It was a Cardiac Arrest, not a Heart Attack (I always thought they were one and the same thing, but apparently not).
This is good news - this MIGHT mean that he could play again - although he would be banned in Italy and England.
Didn't Edgar Davids (??) have a similar problem, but was allowed to continue playing with the proviso that there was a specialist heart team always at the side of the pitch in case he collapsed????
From the Daily Mail (so it MUST be true....!):
WHAT IS A CARDIAC ARREST? HOW IS IT DIFFERENT FROM A HEART ATTACK?
A heart attack and a cardiac arrest are not the same thing
A cardiac arrest is when a person's heart stops pumping blood around their body and they stop breathing normally
A heart attack is when one of the coronary arteries becomes blocked. The heart muscle is robbed of its vital blood supply and, if left untreated, will begin to die because it is not getting enough oxygen
Many cardiac arrests in adults happen because of a heart attack. This is because a person who is having a heart attack may develop a dangerous heart rhythm, which can cause a cardiac arrest
Source: British Heart Foundation
Christian Eriksen releases first public statement since cardiac arrest: 'I won't give up' | Daily Mail Online