The "whooshing" or "clicks" are the traditional methods of diagnosing problems with the structure (plumbing) of the heart.
It's a very subjective method of detecting problems, and the odds are, in a 24 year old with no symptoms,it'll lead to nothing more.
The gold standard for diagnosis is the echo. It sounds like they are chucking in the ECG for completeness, which is fair enough.
Please leave some feedback when you are flying an Airbus :-)