Thank you for the input.
When the numbness is more in the thumb and wrist area it is most probably due to pinched nerve in the spine or arm. It can be due to carpal tunnel syndrome. Neuropathy can be possible too. In heart attack you may feel numbness in the left arm,but it usually starts in the upper arm and radiate downwards. In pinched nerve application of warmth, tylenol, physiotherapy can help. However an examination by doctor should be taken for investigations and intervention as necessary.
Any query, please feel free to ask. It will be my privilege to assist you. Regards.