A 5 second run that doesn't sustain may not be anything to be too concerned about but it is important to get your heart fully checked to see if there is a cause or other issue like leaky valves going on. This said, it can be easy for people to mix up VT with SVT. Were you specifically told it was VT or given a paper that gave you a diagnosis? I have had people who were diagnosed with PSVT think it is VT when that really means SVT that comes and goes. VT that doesn't sustain is generally labelled as NSVT. It can be very easy to mix them up so just wanted to clarify that you were indeed specifically told you had VT because SVT is a lot less concerning. Either way, if your heart is generally healthy VT is not necessarily a threat. If it becomes a danger to you odds are you would get a ICD put in but work to get your heart checked out first and go from there. Best of luck and keep us posted on how you are doing.
I think the medical staff is being cautious with your condition, that's a good thing. Your young, and if you've had no history of heart disease, that's a big plus. Non sustained VT (NSVT) in situations like youra is usually something that may need to be monitored, bUT not be overly concerned about.