I will try to get some of the values I test tomorrow as I'm pretty tired today already and will go for some sleep (one fast thing I can tell: after a solid blast of tren, which usualy sends lipids down the shitter for many, mine were affected just very slightly. Which I'm sure is genetic, as there are/were no people with heart disseases/diabetes/obesity in my family tree.). You raise interesting points, could you elaborate on the electrical conductivity? I may do these tests next time around as I have some "access" to a medical care system through my relatives so I can get pretty much any test I want for a lower price or even for free. Myocardial fibrosis is interesting too, but I'm on quite an extensive regimen of supplements, probably like 30+ substances (mostly natural), I think I'm outweighing at least some of the possible negatives (eat clean, no drugs or alcohol ever, etc..).
Genetics will play a part for sure, so you are probably lucky on that part, or some other element of your diet or lifestyle in general is just right to mitigate the impact of gear on your lipid values.
In terms of the electrical conductivity, there are quite a few studies that seem to show, steroids can effect the conductivity of cardiac tissue. It doesnt seem to be a permanent change, but effectively the signals regulating the heart beat become erratic, in the studies I saw, they found that it was intermittent and occuring at certain times after intense physical exercise like cardio for example. Its not clear whether this is a physiological change or due to some kind of issue relating to electrolytes or mineral imbalance. I think one of the theories was that calcium was building up in cardiac tissue which impairs conductivity. Having an EKG would be worth doing anyway if you have access. Its not guaranteed to show anything up in regards to this specific issue, but it might show up other things. In my own opinion I would think if EKGS are used and they dont show a problem, that might suggest that its not a structural or physiological change, but rather some temporary imbalance caused by steroids affects on electrolytes or mineral balance.
Myocardial fibrosis happens to everyone but ramped up heavily in steroid use. There are things that could be done to reduce the effects via diet, red wine, once again, has been shown to possibly reduce the rate of fibrosis. Periodic periods of fasting (not good for bodybuilding) seem to be of benefit to the heart, cardiac tissue seems to do better on ketones.
I dont know if you are in US or Europe but the test names differ.
I the US you wont get APoA/B but something called LDL-P LDL-C, I think the test is called LDL NMR.
One other one worth doing is:
HBa1c - glycated hemaglobin
Ferritin
ApoA/ ApoB or NMR/LDL-P/LDL-C
HS-CRP
LP(a)
LP-PLA2
I dont know how old you are but if you are closer to 40 and have access a CAC or coronary calcium scan test is worth doing if you can get it cheap. It is the most effective test as it physically shows you what is actually in your arteries in terms of plaques so its very useful in seeing if you are setup for a heart attack/stroke. They suggest you only have this done once in your life, probably best after you have had children :-) as it involves a large dose of radiation and best done towards middle age. LP=PLA2 is your second best option to the CAC and is just a blood test.
I do believe that if one truly lives a healthy lifestyle, then they can mitigate some of the effects of steroids, however most of the effects we can mitigate are on the periphery, liver function, kidney function, test levels, hair loss, gyno,. Lipid values are more serious and again they can be regulated. Steroids actually do have some benefit in that they increase NO production which in turn has a positve effect on endothelial function but what we cant be sure of, and dont really know about, is what structural/functional affects are taking place in cardiac tissue. These are changes that are most likely long term and its not clear whether they reverse with time off.
Aside from these visible and "hidden" or noticable side effects, the main thing that cannot be mitigated is one of the fundamental priciniples on which steroids work, which is significantly increased levels of IGF-1. Having constantly elevated levels of IGF-1 by its most basic function means you have much higher levels of cell turnover...in the most basic sense aging. Basically you have tank of "life fuel", the more IGF-1 you have floating around everyday, the faster you burn your life fuel. The less IGF-1 the slower, we do need IGF-1 as we need it for the various normal anabolic type functions in our body, but we dont want to have it sky high 24/7 which is what steroids and a high calorie high protein diet will do. Im not saying only steroids do this thought, you can be 300lbs lazy obese guy eating mcdonalds every day, sitting on his backside all day and eating shit loads of food will also keep his IGF-1 elevated. Ideally you want to have periods of high IGF-1 during the day and then lower levels for the bulk of the day. Anyway I'm starting to digress into the realms of longevity

If you can get those tests, it would be good to see what they come back as.You can calculate some of your risk factors based on Lp(a), Athe apo's and pla2.