Hello!

I am a 20 year old male. I have been diagnosed with SVT. I have had SVT my entire life. Generally I would have an episode once every few months. The episode would result in my heart beating approx 180-250 times a minute. Sometimes I would be able to terminate the episode by holding my breath, although other times I would just have to wait it out for about 10 minutes or so for it to stop on its own. After a particularly bad episode where my heart started beating 300 times a minute and would not stop on its own ever after 25 minutes (had to call the paramedics to stop it with Adenosine), I went through a cardiac ablation, and it was considered a partial success, as my SVT episodes, although happening more often (once or twice a month), are always able to be stopped 100% of the time within a few seconds, by holding my breath. My cardiologist has told me that the type of SVT I have is benign, more of an annoyance, but carries no serious risks.

I am taking 25 mg Metoprolol to further help control the SVT. My question is regarding the substance MDMA. I completely understand that you must advise against the use of any illicit substance as such. I am also very aware of all the potential risks of the substance as well as ways to minimize risks. I have used MDMA before multiple times with no adverse effects, although it was before I started taking Metoprolol. My question is, could there be any possible dangerous interaction between pure, MDMA and 25 mg Metoprolol, and if so, what could the interaction be, and what risks could it carry? I came across this study that seemed to indicate that using Pindolol with MDMA actually helped prevent increases in heart rate, which would indicate to me that using the two together is not a problem, however the beta blocker that was studied is a different one than the one I use. I'm assuming that the mechanism of action could be different for different beta blockers, so I wanted to ask to make sure I checked about it. http://www.ncbi.nlm.nih.gov/pubmed/20378736

My second question is, is there any significant chance that a person with benign SVT, using MDMA, could be more at risk for adverse effects, than someone with no heart conditions? And if so, are we talking, a slight increase in risk, or significant increase?

Thank you for your time!