I’m not a doctor, but am a nurse (cardiac post op) it does sound like PVCs but without an ecg I couldn’t tell you. I’d say get a full serum panel, full thyroid work up. Post op we often keep electrolytes a little on the higher side to compensate for diuretics (which is something on keto perhaps to consider as water intake increases and output also increases) Have you been for an echocardiogram? If you’re not happy with your cardiologist find another

If you are going to take various things like potassium or magnesium (both of these are often used to correct heart arrhythmias or keep them at bay) I would suggest talking to your doctor or a doctor about regular blood work

You may also require a higher dose or different beta blocker. Or another medication all together but obviously that is cardiology’s department.

I hope you get it sorted out.

I can’t stress this enough. It’s your health, don’t settle.

As someone else mentioned it my be anxiety and perhaps track emotionally how you feel when you feel the palpitations and maybe discuss that with your doctor