Hello, thank you for the query and welcome to HCM community.
There are many causes of
palpitation (heart racing) . It may be cardiac, psychiatric or other miscellaneous causes. But, a feeling of
dizziness along with palpitation usually indicate haemodynamic instability resulting from cardiac arrthmia.As you mentioned you have history of regurgitation in your echo, so valvular disease like mitral or
aortic insufficiency can be the reason.
valvular heart disease can cause arrthmia like
SVT, AFib, short runs of non sustained VT which may. be manifestated as palpitation and dizziness. So, consult with a cardiologist for complete evaluation. Hope, this helps.