Deep breaths and pain?

Hi all, when i do my yoga nidra session before bed i take deep, slow breaths instead of normal breaths because noticed i can't always enter the "nidra" state by normal breaths, and this prevents me from a good night sleep.

The day next after lunch i notice a little pain on the chest area, right and left part of it, and feel a tight feeling, as i can't completely inhale as i want. If i go walking or listen to rhytmic music this feeling goes away.

Could this be angina? Or worse, could this lead to heart attack if i do it each night (was thinking 30 minutes-1h before bed throughout yoga nidra session)?

Thanks!