I am 25 and have a diagnosis of PoTS based on my symptoms (tachycardia, exercise intolerance, low blood pressure and mild shortness of breath). Prior to these symptoms emerging 18 months ago, I was active and fairly healthy. Now, I find even light exercise quite difficult, as my heart rate shoots up and takes a while to come down. I can get up to 150bpm just stretching or standing up on bad days, which also makes me feel slightly short of breath, as if I've been running.
I have been seeing a cardiologist (privately), who has conducted two 24-hour holter monitors, which were both normal. My pulse and standing/sitting blood pressure are also checked regularly. I have been prescribed midodrine and ivabradine, which seem to help a little bit.
My oxygen levels are normal. Occasionally my O2 will drop down to 93-94%, but it always comes back up again quickly.
My worry is something like hypertrophic/dilated cardiomyopathy, which apparently sometimes only shows up on echocardiograms or MRIs. Should I be worried about this? I suppose I am afraid that I will drop dead.