This is a bit of cut and paste from a cardiology text book chaps.
What it says is if your ECG is normal then you are fit to fly. If it is abnormal you need some further tests. Nothing new or alarming here!!!
In fact the concern in young people generally is abnormal electrical circuits in the heart such as Wolfe Parkinson White which can lead to sudden death. That is why many schools offer an ECG to their pupils. And one reason why an initial medical involves an ECG. Cardiomyopathy more commonly presents in older people with shortness of breath. It is pump failure and we investigate it initially with ultrasound (echocardiography) or MRI. However we rarely see it in younger people outside pregnancy, and palpitations can be a presenting cause. Of course if you get palpitations you would stop flying and tell your AME anyhow.
but a good read for budding cardiologists.