I don't understand the connection from a medical standpoint but I know if I'm bad and have a high sodium day, I will retain fluid (up to 5 lbs in one day) and my heart will act up more than usual. Lots of pounding, increased ectopics and flutters of tachycardia. Once the fluid drains off over several hours, things quiet down in there. My thought is the increased fluid puts an extra strain on my cardiovascular system.
I don't know what the corrolation between palps. and salt are but the one thing i do know is that salt raises your blood pressure extremely fast. If you are taking metroprolol that should be relieving your episodes somewhat at least and if you are still having problems i would give the doc a call tomorrow to find out why its not working. It seems to me if you are on a beta blocker such as the metro. and it also lowers your blood pressure and you have a high intake of salt common sense would tell me you are negating the purpose of the meds you are on because one knocks out the other.. maybe someone else knows the answer to this one......