No man...arythmias are not caused for high blood pressure or high cholesterol levels. Arythmia is an irregular heartbeat caused by a problem in the heart electrical system. Is very complex and difficult to explain. Imagine that an electrical pulse is going around your heart, causing your heart rythm. For a normal beat, this electrical pulse has to do the whole route around the heart. The speed of this electrical pulse changes depending on the body blood and oxygen demand. Now an irregular heartbeat is produced when for some medical reason that I don't know, this electrical pulse instead of going around the heart, jump from the middle of the route to the other side of the heart, going to the starting point like in the half of the time. You know what I mean? So instead of having a complete turn around, you have just the half of the turn. That causes a premature ventricle contraction. Now from what I've read, this kind of arythmia is benign. Because the variety of arythmias is big. Supposedly everybody has this type of arythmia in different degrees. The people that get them for example from dbol is because they have a higher chance to develop this kind of irregular heartbeats. And usually they will develop this using any kind of stimulants. As I said before, in my case for example I was having low quality of sleep and drinking too much coffee...that fucked me up. Now I have only sporadic irregular heartbeats. And of course I have them stronger when using d-bol. Don't worry. There's a lot of people that feel this from d-bol. In my case, I start with low doses increasing over a period of two weeks. That makes me get used to it.