Thank you for your question .
First of all it sounds as though your pacemaker is working well. I do not think this has a direct impact on your headache .
You need to consult a doctor to examine you for the multiple reasons for headache , way to many to mention here. It is important to decide whether these are migraines you are getting , as the treatment is very specific and differs from other forms of headache . Headaches
should always be taken seriously until properly diagnosed as there are sinister causes of headaches.