Calcium/Magnesium/Potassium at the cellular level

[LINDA CAROLEO]

Hi:

I started getting SVT's and PCV's about 2 1/2 years during an extremely stressful period.  My electrophysiologist tried an ablation about 9 months ago but he could not map because they were all over the place on the left side of my heart.  He said there there is equipment out that will allow him to (I think he said) cut a hole in my heart and get to the left side, and this equipment also is supposed to have superior mapping capabilities.    While I'm waiting to do this I decided to try to determine if these arrhythmias could be caused by too much/too little calcium/magnesium/potassium.  I did some research on the web and found the following site: http://www.exatest.com/index.html  which says that you could have normal serum levels, but your cellular levels of these could be off (they sell the kit to test for this).  I've also spoken to nutritionists at the local health food store who tells me that not only deficiencies in magnesium, but also deficiencies in calcium (which I thought raised your heart rate) could cause arrhythmias.  
1) Do you think it is worth it taking this test?  Can deficiencies in calcium/magnesium/potassium cause arrhythmias and is that very common in this country where we're not starving?
2) I know I'm slightly anemic, could this be a part of the picture?
3) Have you heard of the equipment to do the ablation that I described?

Thanks so much for you response.

[CCF CARDIO MD JMF]

Dear Deb,

Diuretics of any kind could cause this including diet preparations.  You could be dehydrated or could have an abnormal excretion of potassium.

[Deb]

Went to ER with tachycardia, palpitations, and chest pain.  Only abnormalities were low potassium, high creatinine, high BUN.  What would cause this?

[CCF CARDIO MD JMF]

In response to your quesitons:

1)Do you think it is worth it taking this test? Can deficiencies in calcium/magnesium/potassium cause arrhythmias and is that very common in this country where we're not starving?

this is very common in certain people and low levels of any of these will increase the irritability of the heart.  

2) I know I'm slightly anemic, could this be a part of the picture?
This would be less likely to cause arrhythmias, but this should be evaluated.  This may represent iron deficiency.

3) Have you heard of the equipment to do the ablation that I described?

New phase array displays are now available to do 3d reconstructions of electrical pathways.  This may be what your are describing.