Is having a Persantine stress test safe with heart palpitations?

Hello,
I am a 55 yr. old female, and have been experiencing heart palpitations for over 15 years.  There is a history of heart problems in my family so this has always been a concern of mine. I have the palpitations constantly around the clock and they occur very frequently throughout the day and night, and often when they occur I feel like I lose my breath for a split second and I cough.  Not 15 minutes can go by where I don't feel palpitations, they're that frequent. I usually feel my heart skip 2-5 beats but I felt one recently, while in bed trying to fall asleep, that had 12-15 skipped beats, I alarmed me as I didn't think it was going to stop and made me feel lightheaded. I've even awakened from a sound sleep feeling palpitations. I've worn numerous holter monitors over the years and have had a few echocardiograms and stress tests, with none of them showing anything 'serious' with my heart.  I  tell my doctor how I have always been concerned about them and don't like how they feel so she is sending me for a Persantine stress test.  I have read about this test and I'm not comfortable with an injection giving me a feeling of possible shortness of breath, tightness in the chest and extremely rapid heartbeats and I am concerned about having this done with the palpitations I always have. Could anything serious happen, such as a heart attack, as a result of this injection?  
Are there any risks to having this test?  A friend of a friend had one and he said it was horrible how it made him feel and frightenend him.
Also would this test tell me if I have any congenital heart defects?  One echocardiogram I had 10 years ago showed my aortic valve is trileaflet and one I had last year said my aortic valve was poorly seen but "probably bicuspid" so my doctor told me not to worry about it. I am seeing a Cardiologist but unfortunately not until December.
I hope you could help me in aswering my questions and giving me your opinion.
Thank you,
Michelle

[Michael J. McWilliams, M.D.]

A minority of patients have that shortness of breath/ chest pressure sensation with persantine.  It is not dangerous if you don't have asthma or reactive airway disease.  Palpitations are not a contra indication to a persantine stress test -- this is done commonly for palpitations.  You may have symptoms with it but they usually only last about 5- 10 minutes during the stress test.

There are risks to a stress test including about a 1/1000 risk of heart attack or possibly death.

Persantine stress tests will not assess valves.  An echocardiogram is required for that.  It is important to know if your valve is bicuspid because bicuspid valves are at risk for narrowing and requiring surgery to correct.  If it is narrowing, there is usually a loud, characteristic murmur.

I hope this helps.