I woke up with my heart racing and numbness in my left side. i have never felt such a thing, no other symptoms and now feel ok. what to do?

Arrhythmia : You may have a supraventricular arrhythmia or rapid heart rhythm coming from the upper portion of the heart. You probably should be evaluated to exclude structural heart disease, thyroid disease of abnormal blood chemistries. Then if the rhythm abnormality is found it can be often treated with medications. If problems become very frequent or severe the disturbance might be curable with radiowaves.