Testosterone at supraphysiologic elevates my HR, anabolic steroids increase the sensitivity to catecholamine uptake, beta adrenergic receptor stimulation induced by test or other AAS will increase sensitivity to catecholamines (of which esp epinephrine can cause PVC’s and accelerated HR).
What kind of irregular HR are we talking about? Tachycardia or potentially serious rhythm abnormalities like atrial flutter. Some AAS will cause this issue more than others. Personally on drostanolone I never noticed any alteration in HR, test and anavar however and HR was higher (oxandrolone induced consistent and constant tachycardia due to very high BP… if it was Oxandrolone that is)
The question is, do you have a familial history of cardiac complications? What’s you’re history like regarding prior drug use and/or exposure to toxins. Anabolic’s in themselves are also (aside from modifying sensitivity to catecholamine release) directly pro-arrythmiac through various mechanisms… or at least rodent models demonstrate them to be, genetic predisposition will determine individualistic sensitivity to these effects.
Do you take any meds known to interfere with ECG readings (various antidepressants can prolong QT interval etc). That being said it’s very possible you just aren’t cut out for using test at high doses like 500mg, try 300mg? I notice even 350mg gives me palpitations (although not by itself per se, when combined with the defamfetamine I’m prescribed to study), granted it’s possible testosterone itself causes these issues for me which would be incredibly depressing. I know I can tolerate 250mg without any issues regarding heart rate and/or palpitations (although my RHR will always go up 5-10BPM following a dosage escalation.
Theoretically over time on cycle you’re bodies receptors that are sensitive to catecholamine release should down regulate over time following initial hormonal induced upregulation. Drugs that block said receptors (beta blockers) may be of help, however it generally isn’t a great idea if you were severely symptomatic. It should be noted the vast majority of the populace experiences PVC’s at once point or another, I sometimes get them (though I haven’t had one for about a week now).
Did you wear a halter monitor? How many ectopic beats were revealed over 24hrs? What was you’re avg HR?
I totally understand though, if I was to find out there was nothing I could do aside from risk arrhythmia regarding cycling, I’d probably do it anyway out of sheer frustration. I’m fucking slightly under 5’5, GH would’ve gotten me to a normal height but noooo (and it does still irritate me somewhat) furthermore I have chronic pain amongst a variety of other ailments, bodybuilding is one of the few variables I have in my life that keeps me feeling good, it isn’t something I’d give up for the world (and associated with bodybuilding comes the prospect of performance enhancing drugs, if I dedicate a TON of time and energy to said activity, of course I want to look that part, though it’s more for me than it is for anyone else)
That being said a cardiac evaluation, stress test, echo etc may be beneficial. I think you’d want to know if god forbid you have some kind of undiagnosed heart defect no?