Angina Support Group

Cardiac ischemia is the name of the condition where you have a lack of blood flow and oxygen to the heart muscle. Often that results in angina but for some there is no pain associated with the ischemia. That's what's called "silent ischemia".

Are there any symtoms

No, not really. It's detected by a portable EKG or sometimes a stress test.
You might detect some weakness when exercising but not necessarily.

What does portable EKG throw up ?

It can show when you're having a cardiac event that doesn't occur in the doctors office. Sometimes it's precipitated by getting out of bed, eating, getting stressed...

Imagine that you are lifting weights, trying to build your biceps. to do that you're supposed to use a heavy weight and exercise the muscle to exhaustion... keep lifting the weight until the muscle just can't do any more.
When that happens the muscle is spent; all of the energy in the muscle has been used up, there is no more oxygen, sugar... nothing and the messages from your brain to flex that muscle are ignored.
It's the same with ischemia. The heart muscle is just another muscle. When blood flow is interrupted to an area of the heart that part of the muscle is unable to get adequate nutrients to function and even thought the electrical impulses are reaching the muscle... nothing. When that happens the electrical impulses that are usually given off are now slightly different. That's the cardiac event that can be detected by wearing a portable EKG.

BTW, in a situation like that only PART of the muscle is deprived, and when the pulse rate slows again the area recovers.