My left hand briefly went numb and now feels a bit weak. had pressure in jaw and throat earlier. echo, stress, blood work and holter all normal.

Numbness: The work up for hand numbness should also include screening holter extended or full disclosure event recorder to rule out paroxysmal,a fib. Additionally a bubble study might be helpful to rule out pfo

Worrisome: Generally in a young person with no other risk factors brief numbness on one hand would be less likely to be due to a TIA. However if weakness accompanied the numbness I would be more concerned and would likely advise my patient to take a baby aspirin and go to the ER to be evaluated. Consult your physician and consider going to the ER if he/she is not available.