How urgent is it when I get sudden fast heartbeats either while working, like today, or awakens me in the middle of the night. It started 3 days ago. I also get nausea, light headed and a squeezing sensation in my left upper arm along with the tachycardia. Do I just schedule an office appointment or go to the ER?
Hello, Your symptoms could be related to possible cardiac arrhythmia. For this reason, I would recommend consulting with your attending physician for a physical exam, a resting ECG and a cardiac ultrasound.  Some blood lab tests (complete blood count for anemia, thyroid hormone levels for thyroid gland dysfunction, blood electrolytes for possible imbalance).  An ambulatory 24-48 hours ECG monitoring would help examine your heart rhythm trends for a prolonged time and exclude possible cardiac arrhythmia.  Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor. 