Not really a "tip", but I found the videos from this channel very reassuring and elaborate.

https://www.youtube.com/channel/UCxt...pX1B9sGbRudG6g

The creator is Dr. Gupta from York Cardiology, a cardiologist, that talks about subjects revolving around the heart - palpitations, ectopic beats, blood pressure, anxiety's role in arrythmias etc.. His explanations are very down-to-earth, made in a simple and reassuring way.

If your fears revolve around your heart function, then you should give this kind doctor a try.