Hi Diane,
Sorry to hear about your dad's experience. Medical problems on airplanes, especially long flights, can be hair raising.
I am not sure what to tell you about the "heart virus." There aren't many viruses that attack the heart. The ones that do can leave some very long last effects -- they are not 4-8 hour ordeals.
I am not sure if the doctors were trying to simplify their diagnosis to something they thought you might understand, but I cannot tell you what happened based on that information.
On a good note, most airplanes now have
defibrillatorsImplantable cardioverter-defibrillator , so if someone is in real trouble and develops a life threatening arrhythmia, at least they can treat it.
If you think there is a problem with his heart, have him seen by a cardiologist. You should be able to get a straight answer on whether this was a
cardiacCardiac catheterization
Cardiac tamponade
Left heart ventricular angiography problem or not.
Sorry I cannot be more helpful. Good luck.
Since you said your dad is a very healthy person odds are he will suffer no ill efects from it, but if he is concerned he may want to have an echo and EKG done just to make sure.