My Cardiologist suggest that I ask my psychiatrist to find a replacement for this medication, but she's tried pretty much everything, SSRI's etc to help with my anxiety and depression and sleep, and the Quetiapine(Seroquel) has been the only thing I could tolerate the side effects of. My psychiatrist doesnt think the heart issues are from the Seroquel. I quit taking the Seroquel cold turkey one day, and after that 24 hour period of not taking the 200mg daily like I have been taking, is when the heart issues started. Even though Im back to taking 200 mg a day, Im having random high heart rate events. A lot at night when Im sleeping.