Since this has been around for decades and has been increasing over the years, it’s been a killer long before the vaccine.
It’s not new. It first became a diagnosis in 1980. The number one common factor is “young athlete.”
It has been, and some of the culprits are the increased use of creatine dehydration, and steroid use. I personally know one Olympic class athlete that had heart surgery at 24 years old, and also have discussed this very issue with a power lifter. He says creatines can dehydrate a person to the point of heart attack, and they are available over the counter. He also said steroid use is on the rise.