Thank you for your query at DoctorSpring.com.
I think your main problem is anxiety and the racing heart rate is primarily due to anxiety. Zolpidem does not cause your heart to race.
The medications you are on, are probably not adequate to control your anxiety and that may be leading to a heart rate acceleration.
So you may consult your psychiatrist for a better anti-anxiety medication.
As a cardiologist I would advise you to undergo a 2D ECHO test and a 24 hour Holter examination to rule out any other cardiac disease and to confirm whether all this due to anxiety itself.
I hope this was helpful. Feel free to ask queries.
Dr Vivek Mahajan,