This is a very important subject, and I am so glad to see Annie bringing it up here.

Another crucial factor is electrolyte status. I've noticed that many here use Prednisone at times, and this drug can seriously lower potassium and magnesium levels.

When this happens, cardiac arrhythmias may occur, and blood pressure may go up. If you use any other drugs, like methadone for pain, SSRIs, or TCAs (tricyclic antidepressants for pain) and many others, you could develop a long QT situation.

Here is a website from the University of Arizona, which specializes in this subject:
http://www.azcert.org/

Some people may be genetically prone to this effect, but others without the genetic tendency can also have a QT event if they become too low in potassium and magnesium.
In fact a very common drug called Propulsid was taken off the market because of this interacting with diuretics which deplete both electrolytes. When doctors failed to respond to the warning letters from Janssen and FDA, it was pulled off the market. It was a very useful drug for GERD and gastroparesis, and nothing remains quite as useful. It was unfortunate, but does illustrate how sensitive the heart can be.

One does not need high doses of magnesium and for MGers here, really high Mag is not indicated. But keeping at the RDA level, will lower BP and help with heart functions considerably.
Chosing foods high in potassium can help too, if you are on Prednisone. One warning sign before the heart is affected, would be excessive fatigue and muscle cramping.
The new revised intake for daily dietary potassium is now 4.5 grams. One quick way to get potassium is with V8 juice. It has about 800mg/12 oz can.

This nutrition site is very good for showing food contents:
http://www.nutritiondata.com/facts/v...roducts/9873/2
This example link is for edamame beans-- very tasty flavorful way to get your minerals and some protein. Them come frozen/cooked and you just defrost in boiling water for a couple of minutes, and they are great in salads, etc.
Search any food, even some processed ones are on that database.