Thanks for the post,
The heart rate and rhythm responds to changes in your breathing. When you take in a deep breath, you activate the parasympathetic nervous system which can lead to extra or skipped beats. This is normal.
Holding your breath also leads to changes in the parasympathetic nervous system, which will cause an initial decrease in heart rate. Depending on how long you hold your breath, the heart rate may then speed back up.
A hiatal hernia can be associated with grumbling at any location in your chest. If air was rushing into your heart, you would be dead.
Hope that helps.
I have noticed those same changes in my hr/pulse when I breathe in deep or exhale. Good to know its normal.
this response to breathing is called sinus arrthymia. it's completely normal and i have it as well. as you inhale your heartrate speeds up, and as you exhale it decreases.