Another important reason is that the physical examination items of this era are too simple. The heart examination in the check-ups that children undergo annually at school, as required by the state, mostly involve an electrocardiogram and a chest X-ray, some don't even include an electrocardiogram. Lacking instrumental detection, doctors attempt to detect subtle heart issues using a simple stethoscope: Hmm, the doctors who can do this are practically divine.
Moreover, relying solely on an electrocardiogram and a chest X-ray is very limited in diagnosing heart disease.
Take the simplest example, a 16-year-old girl in bed 12 with an atrial septal defect.
