Does anyone have ideas on effects of LL on heart

If you lengthen your legs by a much, you're over-extending your veins and blood vessels but your heart and other organs remain the same size. Thus wouldn't that cause pressure on heart load, so it has to pump much more amount of blood even though it is not designed for that, causing heart-related problems like heart failure and so on?

Does anyone have ideas or studies on this? For some reason this is not adressed by any LL surgeon, which had me worried

Don’t taller people have shorter lifespan? This could be part of the reason.

I don't know about any scientific research, but anecdotally I have a much harder time doing cardio now compared to pre-LL.

I used to be able to run a sub-5:30 mile, but now I can't even finish a mile at a 10:00 pace (which is slower than my marathon pace pre-LL). My heart rate will go over 190 BPM at that pace and I'm a bit concerned about getting a heart attack or something so I don't push myself. I can pretty much only do elliptical, biking, hiking, and casual sports for cardio (though I'm much more of a bodybuilder when it comes to the gym anyway).

I don't regret doing LL one bit though in terms of sports though. My days of distance running were long past before I even started LL (I hadn't run any half or full marathons for over 5 years as of my surgery date). I can still play a lot of different sports with friends and have fun in the amateur leagues I participate in and I'm still in very good shape visually so it's not a concern to me.

99% of the time modern humans don't need to run more than 30 seconds anyway (to catch the train or w/e)