Not to disagree with the narrative (this covid vax is deadly, no question!), but that kid really looks like he might have Marfan Syndrome. Not uncommon for people with Marfan to suffer heart problems. Lots of conjecture going on here. It's very useful to look at teenage heart related deaths over time (as a population group), but not too useful to focus on individual cases as any one case can be an outlier for or against the hypothesis.