I have a feeling in my chest like my heart is sinking or slowing to the point of a slight loss of breath. It happens every day now and sometimes as much as 5-7 times in a minute. This is beginning to scare me. It feels like my heart is interrupted when beating and stops abruptly then beats hard when restarting or something. I have Tachycardia and take Toprol XL for that (Metotoprolol XR); I never have had a great heart rate even in the past (5-6) years since taking Toprol, it is usually about 100 bpm by late evening while resting supine on the couch. I also take Lisinopril HCTZ for high blood pressure. That is working great for the past 5 years together. I have a great BP with these meds. I also have Multiple Schlerosis (Relapsing and Remitting). I have lesions in my Brain stem, Thorasic and Lower Lumbar; the wors in the Thorasic and Brain Stem area.
Hello, I passed carefully through your question and would explain that your symptoms could be related to a possible cardiac arrhythmia.  For this reason, I recommend performing an ambulatory 24-48 hours ECG monitoring in order to investigate for possible cardiac arrhythmia and some blood lab tests (complete blood count for anemia, thyroid hormone levels for possible thyroid gland dysfunction, blood electrolytes for possible imbalance).  Hope I have answered your query. Let me know if I can assist you further.  