If the pain reoccurs when you resume the activity at a slower pace stop, and follow the instructions in the above diagram.
This pain should not affect your recovery.
You should not have heart pain at rest. If pain does occur and does not pass away within 15 minutes (after taking GTN spray), then contact 999 immediately.
If, during exercise or walking, you get chest pain, excessive breathlessness, tiredness of dizziness, rest immediately and only resume activity when the pain has passed.
If you have to repeat the procedure on a regular basis consult your Doctor.