Is it possible for a teenager to develop stress cardiomyopathy "broken heart syndrome"?

It is very rare. Broken heart syndrome, also known as takotsubo cardiomyopathy, is a specific condition where part of the left ventricle develops poor function and appears to balloon out. It most commonly occurs in women pver 50, but there are rare reports in children and adolescents. The onset of this condition is linked to an acute stressful event. Function usually returns to normal within one month.
No. There are three types of cardiomyopathies, hypertrophic, dilated and restrictive.