What can a echocardiogram detect in a healthy-looking teenager?

Several things: You can look healthy but still have structural abnormalities of the heart. If there is a murmur, a valve may be leaking or too tight. There can be holes between the two sides of the heart. The heart muscle may not be contracting normally or may be too thick. The aorta could be dilated. In a teenager one could well be looking for congenital problems. (abnormalites that you are born with).

Different things: It can detect any congenital (inborn) abnormalities of the heart muscle, valves or blood vessels. It's a mon invasive routine test that a physician would order if the physical exam reveals a murmur or the ECG looks suspicious or the teenager had symptoms.

Congenital heart dz: Usually only done if murmur heard on exam, suspicious symptoms or abnormal ekg. Some defects that might be found in teens are ASD or vsd -holes in the wall between r and l sides- which can be treated before the r-side gets stressed. There are also cardiomyopathies like hocm-hank gathers' dz. Shaun white, star snowboarder, got tetralogy of fallot repair around age 5 based on echo and exam findings.

ManyThings,Depending: Your statement “healthy-looking” is key. Most issues of health/disease, a continuum, are hidden inside & do not become apparent until advanced because we have so many ways of compensating. People/drs. Usually wait until signs of problems obvious. Us the safest of medical imaging techniques, yet very quality dependent on machine/tech/person/reader. Best always get video copies, read yourself & save.