I was recently diagnosed with dilated cardiomyopathy. My EF is 35%. I take 3.125 mg of Coreg twice per day. Today, while sitting watching a video, my heart rate, which is usually in the 72 - 78 beats per minute range was up around 90 beats per minute. I also had a single shooting pain down my left arm and a general feeling of numbness in the arm after that. I had this happen once before and the shooting pain in my left arm was so strong it woke me out of a sound sleep. Do you have any idea what might be causing the shooting pain and racing heart rate? Is this something I should be going to the ER for?

Thanks,

Scott