There are no risks for examinations
ECG - Painless, a few leads stuck to your chest, takes about 1 minute
Echo - Ultrasound of the heart, checks for heart size, valves are working fine, and also blood flow. etc. great test for picking up heart issues.
24hr Holter Monitor, similar to what happens with an ECG. You have a device you carry around with you with leads on your chest, which records all heart rhythms for 24hrs. it will show any abnormal rhythms.
X-Ray - My Cardiologist does not think x-rays help as they are so suggestive and diagnosis can be so wrong when it comes to looking at the heart. It helps but Echo is more definitive.
Blood tests - Stock standard blood test covering many things, especially thyroids, as overactive thyroids can cause many a issues with heart beats.
I have no idea about risks when talking about insurance, I have little to know idea about your health system. Our national medicare system covered all my tests I mentioned above, even though I have private cover.
But there are no risks in the tests above, and the only thing that enters your body is a needle when taking blood tests.
I went through all those tests and got my results only three days ago with a clean bill of health on my heart. Does not stop my palpitations, stress and irregular beats
BUT I am improving. I am told to relax and not notice them so much and go on with life. As stress sets mine off like wild fire.