What Causes Heart Palpitations After Minor Foot Surgery?

I started noticing in the last couple weeks since I had minor foot surgery that in the middle of the day while awake it is as if I forget to breath. I only remember because I can feel my heart race oddly and then I gasp for error. It is more irritating than anything. Just seems weird and wanted to know if I should be concerned since this has never happened before. I was diagnosed with mild obstructive sleep apnea, but it only affects me when I m on my back. My bigger concern is that I m awake when this happens. I m very busy and probably could see my primary care in a few weeks. Just want to know if this is something more serious that I should see them right away. thx.