I have two AV nodes is it possible to have two SN nodes as well?

[maryb6]

I'm a 31 year old female. I've had a rapid heart rate (resting 100-135) my whole life and 2 years ago I started experiencing SVT and was cardioverted twice before ablation. During ablation they found AVNRT and corrected it. I was told the IST was something I was just going to have to live with as the meds available would be contraindicated since I have asthma. I am about to undergo my second ablation next week, the SVT has been reoccuring the past few months since increasing my workout routine. My EP is unwilling to even look at the sinus node, maybe I have two of those as well? She is telling me to increase exercise and go gluten carb free and it will resolve over time. After doing a lot of research on my own I am confused.
HELP PLEASE!

[maryb6]

Thank you for the clarification on the AV nodes. I must have misunderstood the doctor. I am hoping that she doesn't solely focus on the AV node and conducts an entire EP study to maybe see why I've started throwing PVC's and PAC's as well. My asthma is pretty active and I have medicine controlled hypothyroid as well. Some of the other posts on here have really worried me about the long term effects of IST, which until recently I have come to terms living with. Do you know of any studies that show a carb & gluten free diet help with IST? My doctor told me to buy the Blood Sugar Solution by Dr. Mark Hyman but I don't have blood sugar issues.  

[CCFHeartMD16]

You do not have 2 AV nodes. AVNRT (AV nodal reentrant tachycardia) means that you have 2 pathways - a slow one and a fast one - within your AV node. The ablation you had attempted to burn and terminate one of them (typically the slow one), but they exist within the same AV node.

The IST (inappropriate sinus tachycardia) means that your sinus node - where the normal electrical signal within the heart originates then propagates to the rest of the heart - is firing too fast (normal is 60-100 beats per minute in an adult). IST is exceptionally hard to manage, and often is either just tolerated or managed with medications such as beta blockers (which if the asthma is very severe, can be exacerbated by beta blockers). Ablation of the sinus node is rarely performed and done and if so, only in the most severe cases. This is because the sinus node is smaller in size, and management of IST often means that the entire sinus node can be damaged. If this were to occur, you would not have the signal originate from the sinus node, but would have to rely upon another area from the atrium to take over as the point of origin of your heart rhythm. If no other area takes over adequately, then a pacemaker may be needed. Therefore, there is no ideal treatment. Things like increasing exercise to improve conditioning may work, but likely not for everyone.