Hi Ruth,   This is a very serious matter that will take some collaboration between your primary doctor and specialists (if you are under the care of a cardiologist). If you were my patient I would need to know more about your heart status and why you have a rapid rate before prescribing or recommending allergy medications.   I would avoid all forms of decongestants (which may increase heart rate and blood pressure). Some non-sedating antihistamines may be considered only after learning more about your heart status. I would likely avoid all oral allergy medications (if there were any uncertainty about your heart rhythm) and go with intranasal steroid spray (for example Flonase, Nasonex or Nasacort) assuming you have allergic nasal problems.   The answer to your question is possibly yes, based on my above comments.   Any medication, over the counter or prescribed, should be carefully reviewed and discussed with your doctors.   Good Luck,   J. Thompson, MD