I'm very sorry to hear that. No disrespect to your friend at all, but that doctor made an ignorant assumption. My guess is that your friend had an underlying condition that he was unaware of. There is no hard evidence pointing to steroids weakening the heart. There's a difference between responsible cycling and irresponsible cycling and/or abuse. If cycling irresponsibly (not controlling e2, not watching rbc and hematocrit, unhealthy eating, etc...) then yes you can do damage to your body, including your heart. But if you know what you're doing and have all the necessary ancillaries and know how to monitor your health, then 750mg of test is not a whole lot. I've done years of research on steroids my friend. That's more than most doctors can say. If there's one thing that a lot of doctors are completely ignorant to, it's steroid use.