Yes, my son experiences “chest pain” when he is low. It really scared me when he complained of chest pain when he was 7 and 8 years old. Now it’s a feeling he is familiar with and just deals with his low blood sugar.
When blood glucose goes low, the sympathetic nervous system kicks in and the following occurs: increased heart rate and respirations, dry mouth, decreased GI motility, pallor, headache, dilated pupils, increased gluconeogenesis which helps power the fight or flight reaction, and other effects. Other neurotransmitters play a role by their reduced levels during anxiety such as GABA, a major inhibitory neurotransmitter, and serotonin. Anxiety is a very uncomfortable feeling. No two people will react exactly the same way.
Ok - so you know for sure your heart rate is low at the same time you are hypo? The only other thing I could think of is to ask if you are taking any other kinds of medications, for diabetes or anything else, and if they could be causing those side effects.