1. Maybe you can try scanning that range sitting next to the remote instead of contact mode. And use a bit smaller step.
There are posts about that.
My heart makes big jumps on a big hit sometimes. It might be one of the bigger hits.
I think the heart can react sometimes a bit more extreme to the contact mode.
2. I believe it may very well be, based on my own experiences and simply known medical info. There are plenty microbes that could (but should not )live in and on the heart or in the blood stream. Even as 'cold-infections'. When you hit those you might or will get a heftier reaction from the heart like you describe. It makes sense.
However all hits are not necessarily always from pathogens. Please take baby steps with those infections. I've been there. I assume you have had your heart checked in general.
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