The numbness of the left arm is not likely due to the heart. It is due to pinched nerves in the neck.
A heart attack causes pain in the left arm and not numbness. Going on for 4 days and your age makes it more unlikely to be related to the heart.
The following measures would be helpful;
1) Neck care in the activities of daily living.
a) No working on the computer for more than half an hour in a single stretch. Same for TV/ IPad/ Mobile.
b) Monitors and televisions exactly in front (180 degrees).
c) Contour pillow: Should fill the hollow when lying on the back /straight or sideways. The principal is neck to be in a neutral position and supported. Available over the counter.
2) Soft Cervical Collar or Brace
3) Cervical traction
4) Anti-inflammatory analgesics like Ibuprofen etc.
5) Some physicians do give oral steroids in severe radiculopathy cases, in whom pain/numbness/tingling is quite significant.
6) Physiotherapy: gradually increasing exercises from passive stretching to active ROM and against resistance regime.
7) Electrotherapy in the form of TENS, interferential and laser, and ultrasound.
8) Hot fomentation
9) Local analgesic patch/ointment/ spray.
10) Gentle massage.
This is an exercise resource;
The investigations advised are;
MRI of the neck.
Nerve conduction velocity study.
I hope your symptoms resolve soon.
I would be happy to assist you further if you need more information.
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