Thank you for your query at doctorspring.com
Fludrocortisine that you were prescribed helps in sakt water retention and thereby relieves the pots symptoms. However it also reduces potassium and may lead to vpcs as a result. If your renal functions are normal you could take plenty of citric fruits or supplements.
If you have a weak heart or left ventricular dysfunction then the fluid retention will
result in increase in bnp. In other words If bnp is elevated you are having heart failure due to Fludrocortisine.
I would like to advise you to get a 2D echo to assess the left ventricular function and if reduced woild like to change to alternatives of Fludrocortisine like midodrine or betablockers ir fluoxetine. Additional measures like compression bandage aerobic exercise avoidance of alcohol low carbohydrate small meals or caffeine maybe tried to reduce requirement of Fludrocortisine.
Kindly inform us the echo report if ypu have already done it
Dr Vivek Mahajan