Guenter,
Thanks for the post.
Q1:"What if anything, is the significance of that?"
It sounds like you have intermittent diaphragmatic and/or pectoral stimulation from the pacer. This should be evaluated, as it may indicate migration of one of the pacer
leadsLead poisoning. Also, it can be uncomfortable (as you have noticed).
See your doctor or device clinic -- they should know what to do.
Good luck.