magnesium deficiency, potassium levels, and palpitations

I am your typical younger patient with occasional heart going out of rhythm and fluttering with sometimes near syncope issues.    I have also had all the usual tests which are all normal.    I have been having this on and off for 5 years now,  and I have lately started looking at unusual explanations.    

At first I thought this was just another kook theory/scam, but I found medical literature suggesting magnesium deficiency causing cardiac rhythm issues.   Also, I have looked at all my labs over the past 5 years and I have had about 15 metabolic panels done and the AVERAGE of my potassium is just 3.5,   the highest being 3.8 and the lowest 3.2.    Nobody every said anything to me about this which I was somewhat curious about.     So, I also find out there is some sort of magnesium-potassium connection?

I looked at the list of tests at my local lab that I could order on myself and I see a serum magnesium test and also an RBC magnesium test which is a little more expensive;   but I have also read in the literature that these tests are poor indicators of the Mg levels in the body.

Some questions...

Would either of these tests be useful?  

What of my chronic borderline low potassium?  

What would be the best type of supplement/drug containing Mg and/or potassium to "experiment" with, and would it be generally be considered safe?

Any thing else I want to know but forgot to ask?

[CCF HeartMD-2]

Many people may have chronic borderline low potassium levels.  I do not think your levels are low enough really to cause severe extra beats.
Would try to eat a diet high in potassium and recheck.  If this does not work, then you can be seen by a renal specialist to determine the cause of low potassium levels.  Magnesium levels would be normal if they are above 2.0.  A multivitamin has magnesium in it so this should be fine.  Potassium and magnesium levels often go together, and if there is a low potassium there also may be a low magnesium level.  There are many websites that can educate you on foods that have high and safe levels of magnesium and potassium to incorporate in your diet.  I would start with these conservative measures first.

[brumes]

I was wondering, if I do get a magnesium test,  which one should i get?   Serum Mg or RBC Magnesium?

[Mom2four85]

did those tests include a tilt table test to find out why you have near syncopal episodes?

[CCF HeartMD-2]

Serum magnesium would be to test to get