Sinus Tachycardia and IVR

I am a 29 yr old female and was diagnosed with sinus tachy at 19 and have been on and off beta blockers since then. Just recently, i am also pregnant, I have started to have more issues and the cardiologist said IVR on top of the tachy and has referred me to electro physiologist. I have been put back on a low dose beta blocker ( waited until symptoms were at their worst because of risk factors). What are the possible causes and treatment? I guess Im just looking for some insight into what Ill be going through next. They did say more tests post partum and that normal treatment for the IVR could possibly make the sinus tachy worse. Thanks in advance for the responses.

[is_something_wrong]

I assume your condition is accelerated IVR (AIVR). Non accelerated IVR runs at 35-40 BPM, so if this is the case, you may have complete heart block or sinus arrest. That's a more serious condition. AIVR runs at rate 60-100 BPM, above that is ventricular tachycardia. How rapid is your AIVR?

AIVR happens when an irritable ventricular focus starts to outrun the sinus node; the beats are faster than the natural pacemaker. Why, is often unknown. It can in some cases be structural changes in the heart, or a small part of the heart is damaged by a virus. Most often, cause is unknown. Pregnancy is stressing the heart, and may provoke a variety of rhythms, most of them completely benign but some of them should be investigated. As far as I know, AIVR is somewhere in the middle of the two; usually considered a benign rhythm but all ventricular arrhythmias should be investigated.

Treatment is beta blockers, antiarrhythmic drugs (which doctors usually don't give to young people) or ablation where they burn and destroy the irritable focus.

What is causing your sinus tachycardia? Usually it's either anxiety, hyperthyroidea or low blood pressure in young people, and if it is the latter, it may worsen if treated with meds that lower blood pressure. Sinus tachycardia is by the way no diagnosis and no arrhythmia, it's a reaction on something stressing the heart, unless you have inappropriate sinus tachycardia or sinus node reentry tachycardia, but if you did, your doctor would probably have told you.

[rlnp22]

Thanks for the response, it is inapproriate sinus tachy, they did put me on labetalol to help. As far as IVR or AIVR they havent said which. They did say they were worried about additional defects or damage which will have to be explored post pregnancy. I am hoping and I think so are they that post pregnancy I wont have symptoms anymore, ie.. palpitations, dizziness, seeing spots, almost fainting - you know all that fun stuff. I didnt have symptoms for a year which is why i was off of the beta blocker in the first place. I do think the AIVR makes more sense considering I have to monitor everything twice a day and i know my heart rate doesnt go below 80 usually, and will register an irregular rhythm at lower and higher heart rates ie..pulse rate 88 and pulse rate 125 and above. As far as the possiblity of POTS, which we did discuss, its hard to tell. Babies and pregnancy do a lot of things to the body and right now its hard to distinguish what the root cause is. Plan now is to go back to electro physiologist 2 months after delivery for another holter monitor and to cut my that doctors can be so vague, I know google provides a plethera of information but it can be make you worry about stuff you shouldnt. Right now, symptoms are much better then they were and i only have a few more weeks until baby is here. As far as not giving beta blockers to young people, i know its not usual, but 10 yrs and i am still on them intermittently.