This poor chap is 18 not a geriatric like the rest of us. This is a totally different situation from the more common ectopics which may signify pathology in middle age
I agree by far the most likely is that this is utter nonsense - personally I would never arrange a 24 hour tape unless I had examined the patient several times unless there is something else........... In which case it will be normal 24 hour tape, red faces all round and on with the flying
In the VERY unlikely instance that there is something wrong at this age, it really is better to have been detected and although you may not agree a blessing in disguise