Just curious, I passed out last Tuesday and went to the doctor on Wednesday. An EKG showed Sinus Brachycardia but when the labs came back it shoe my thyroid levels were low. The doctor called and wanted to start me on Thyroid, I have been on thyroid for 28 yrs, synthroid 50 mg and cytomel 25. Not my reg doc. I have an apart with cardiologist on wed, however, I have been experiencing twinges lack of better term in my left chest are. Not center, left. Not bad, just slight. Could it be related?